I have myself sometimes used bridge rectifiers different from their 'normal' use because I needed such a particular diode arrangement and they happened to come in a cheap package like that. Of course the meaning is disguised just seeing this as rectifier symbol in a circuit. It always makes sense to actually write out the diodes in a schematic to see these kind of hidden (rather interesting in this case) meanings. Thanks for the teardown and detailed explanations about your findings.
I have no background in electrical work and struggle to wrap my head around watts vs amps vs volts (basically anything electrical) but I still binge watch these lol. Great presentation and ability to talk fluidly!
I bought one of these after watching Clive's video. I added an earth wire to the screw and added a large inductor to the output. Also insulated the top and back of the heatsink because it is VERY close to the case.
The inductor is to filter the output. This device works the same way as a light dimmer. If you take apart a dimmer switch, it has a coil and a small X capacitor (100n) on the output.
I use one to control the heating element on my pot still, it works a treat and the controller only reaches 40-45C after 3 hours use @2600W load which I think is acceptable and definitely better than I expected when I was installing a cheap Chinese component.
The great Resistance on the snubber is effecting the time constant of that of the RC configuration (Making the charge time longer). This most probably reduces stress on the capacitor when there is a high inductive load present .
It might be informative to see that power supply connected to an oscilloscope comparing the waveform while using the 4k7 in the snubber to that of a 100 ohm resistor. I wonder how it changes the snubber performance.
Yea that is what I was wondering about. But I trust this schematic compare to what is being pushed out there as 100 ohm. Also the extra resistor that goes with the potentiometer is in the middle between it and the capacitor. They are typically shows to be above the potentiometer. I wonder if that matters or not. Probably not. But the whole idea of the bridge rectifier, I think it is a big deal and what has been explained makes lots of sense. Stability matter big time. I know that without it, any good motor will act as if there is no potentiometer and by pass it and will take off without doing anything.
For what it is worth, a company I used to work for made a whole series of TRIAC based DC motor controllers, and the snubbers were all 47k and 0.01uF (10nF). I never questioned how they got those values, but the circuit and TRIAC worked fine.
Hey Clive I know you've done a computer power supply tear down but I was wondering if you could compare a cheap PSU to a notable good quality one....in terms of quality of components and circuit architecture.
That sounds interesting and I am also in favour of that test. But I know that the brand Seasonic pretty much is the leading producer and that they make most of them. Just look at their warranty of 12 years!
@@sykoteddy Computerparts doesn't have to be crappy, as the requirements rising with every new release of hardware, I still have some 20y old hardware that runs well, even the cheap stuff. Some cheap psus blow up because people tent to run them close to theyr limit. Back than a 250w psu was enough, my 4y old setup runs on 550w psu, the one I build 2y ago already need a 660w psu and a pc with very recent hardware requires at least a 750w. Just as an example, that hardware just ages quick enough.
@@Scootertuner420 Well , in case of PSU's those are probably one of the components that you can not buy a cheap one, nor a expensive, just the wattage you need from a good brand, because very cheap PSU, uses components such as capacitors that are far from what we call a pure component (important for signal conditioning and noise filtering), and what's the problem? Unwanted current spikes, instable voltage, your coomputer will work however motherboard components will suffer, motherboard needs to work with a good PSU so the signal flow will be "smoother" I mean the risk of getting a wrong reading or a exploded cap on mother is lower; Also let's say that you house main fail the chance of a cheap power supply produce a giant current spike and your motherBoard get fried is even higher, I am the guy who bought a cheapier GPU to get a powerfull PSU and guess what nowadays I have a beast gpu with the same PSU chillin cause I know that whatever it happens my PSU will handle the situation while with a cheap your brain will be Please do not burn anything, It is like driving a car with bad tires sooner or later something will happen....
I see that the youtube algorithm has chosen this video for this week. I watched it a few years back but that was on my other account so decided to watch it again. I'm pleased to say that, having watched Clive's videos for a several years meant I understood this so much better this time around. :) Learning by osmosis is so much easier than studying.
Wow! Even though I watched this yesterday it's STILL in my feed! I had to click the three little dots and tell our overlords that I'm not interested in watching it yet again.
I can't admit to understanding all the electronics, but was delighted to hear that this regulator is designed to deliver smoother power at the lower end. My Ryobi drill is very spluttery and rough on slow RPMs and I'm really hoping this will help that. Also, several units of this type have been condemned as death traps, with circuit boards virtually touching unearthed casing, so I'm glad this thing appears to be relatively safe (despite looking hideous and having only one mounting hole on the front). Thanks for the clear and meticulous breakdown.
@@bigclivedotcom Thanks. I'm using my corded drill in a stand. Unfortunately most cordless drills have a pressure-controlled speed trigger which can't be accurately dialled in.
The one thing better than watching you "take things to bits", is you explaining what is going on and whether the bits are good or not. You know so much shit about electronic circuits. You are so good, Clive. And Your Delivery!! Ace, Bloke. ( I am US. I hope "Bloke" is not an insult. I know; "Google it!". I don't think it is an insult. I am rapt when watching and listening to you. Thank You, Clive.
i instantly knew the 470k R should have been 100, as i watched your other triac vid 20 mins ago, the 2 together are amazing. i especially like the journey of FBR discovery you personally embarked on in this one. and saying a diac is a bit like a bi-directional zenner made it's effect instantly comprehendible. thanks
Wow glad I found this video, I have one of these laying in a box back in my garage in South Dakota (I am hiding from the winter right now sitting in the Sun in Arizona at this time) It has been laying there now for a couple of years because I really didn't dare hook it up to my wood router. That what I purchased it for, as my 2.5 horse router is a single speed, and I have some huge bits that cannot run at full speed, lest they shake the whole machine apart. These are made for cutting things like chair rails or making cabnit door inserts. If this works right, I can slow the machine down enough to make the cuts without burning up the bits or tearing up the wood when it begins cutting. MIne came with no labels on the terminals but I have taken it apart and pretty much figured out which is which, then made a label for it so I would remember it the next time I dig it out. Thanks a million for explaining how this works and how to wire it up
Well here it is, another year has passed, the regulator is still laying in the box in the garage. The router has not been turned on, in fact my daughter knocked the hell out of my table trying to get an old bicycle out so I could try and sell it, and I have yet to build up the energy to go out and see how much damage has been done. She did it at my request so I can't really blame her. Doc's say I am drugged out on the prescription meds they have been telling me to take every damn day so now the weaning off of narcotic and anti what ever the hell they are anti drugs. My head seems to be clearing, after 3 months of sleeping day and night with only waking hours dedicated to eating and going to the BR. Nice to be awake again, but most of the damn spring and summer have gone and I have done NOTHING. Damn doctors anyhow.
The label is very logic, it's a very efficient way of supplying the sticker for your case, you peel of the blue part, then you peel off the sticker from the blue foil and stick it to your case where the module is installed. By doing it this way they are 100 percent sure that the sticker doesn't get damaged during transport.
I have one of those. Never have developed the guts to hook it up since it came with no documentation, and no markings as to what hooked to what. I did take the cover off, and sort of figured out how to hook it up, the plan was to control my router for my woodshop so I could cut down the speed when needed. That said, it was advertised as 240/110 volt and I was really hoping it would work but after having problems with about every item I got from China that had the duel markings I decided to let it sit in a box out in my garage. Thanks for the info, when the snow is at last gone and the weather warms a bit, I may try hooking her up to my router table and see if it will do the job for me.
Another point to note about fault conditions is the extra solder they have put on some tracks. In fault conditions this will sputter or could even create a vapour cloud which shorts out *everything*. Fault condition testing can be quite fun actually! Place a sheet of blank paper under the board to catch the sputter, then hang it on your wall!
This is why if I'm drawing out a circuit with a bridge rectifier, and it's not immediately obvious how it's being used, I do _not_ draw it as just a "box" like you did. I draw out the full "diode diamond" instead, because that often makes it much easier to see what's going on if people are using a bridge rectifier in an unconventional way (i.e. not actually as a rectifier), which does happen surprisingly often I've found.
I have disassembled several of those controllers, because it's way cheaper to rip them apart for components than to by components and in every one of them it was 100 ohm resistor in snubber circuit, so I am with you. I think that you are right when you say that they have made a mistake.
This is for resistive loads only (Power factor 1) and is triggered from the load, for an inductive load (power factor other than 1) you need to trigger from the line and there are power controller designed as such. Also when triggering from the line you wouldn't need that extra circuitry to stabilize it. Basically this is just a high power light dimmer. BTW the 10 amp fuse will only give you 1200 watts at 120 volts and 2400 watts at 240 volts...
As a radio ham, I don't actually use those bands (2m/70cm personally, I know some HF guys though), but the only thing worse than an unfiltered dimmer is those awful powerline ethernet gadgets. Great way to turn all the house wiring into a giant antenna for digital noise! 73s, 2E0GXE
+drkastenbrot Very interesting you mentioned this, I decided to check the pair I own. They do seem to be getting a little more efficient now. It costs me £2.09 pm to run mine with no idle at all. They run at 5.6w on full load. Further reading for those interested here: tinyurl.com/nbb9hmc
+drkastenbrot Yeah, I have a system that can get ethernet from one end of the house to the other with no power usage above normal at all! (it's called a cable lol)
+TheChipmunk2008 I wish I had ethernet handy when we had the floor boards up to fit the central heating, I would have loved to wire up the house properly. I have to make do with powerline, not the favourite solution but the best for the circumstances.
+Ben Thomson Usually even WLAN is more performant than that and it at least stays on its frequency. Those thingies are really just made for the "oh my god WLAN is killing me" guys to make money. In the end you'll have more fun putting a proper cable in your house or moving the computer. An idea I just had is just putting a directed antenna(like 20dB) on your WLAN. That wouldn't emit any electromagentic waves where it shouldn't and gives a solid connection as long as no one walks through. 73 DO1JOM
Back in the first half of the 1970s I took a standard electrical box and installed a dimmer in it along with a duplex outlet, the original use for it being to subdue the lights on the christmas tree at the time all incandescent. After that this device was used to dim the bedroom lamps, which worked out quite nicely. Unless I wanted to listen to something on AM radio, in which case I had to turn the unit off, or the generated noise made it impossible to use the radio. I have some salvaged ferrites and should probably install one in there, as I don't believe that it came with one installed. So many years later and the thing is still working fine, excepting a bit of mechanical sluggishness in the pot. More recently I offered to build one of these for my lady, and we went out and got what I thought was the same stuff, and I built it. Unfortunately that one displays the exact instability you describe here. Turn it all the way down so that the light pretty much goes out, and then when you want a bit of light you turn it up but nothing happens until you get to a certain point and then it *jumps* to more light than what I'd wanted, at which point you can turn it down a bit. The dimmers in both cases are the sort of thing that might be installed in the wall, as the last place I lived had one for the light over the dining table (which I had to replace when it decided one day to let the smoke out). I haven't really opened them up to see what the differences might be, or why one would exhibit that behavior and the other one didn't. Do you have any thoughts on this?
I like your comments regarding ceramic fuses. It should be noted, however, that not all ceramic fuses actually have sand inside them. The fuses sold by a particular Australian and New Zealand electronics retailer (known for ripping off Freetronics work) are standard air-filled fuses but have a ceramic case. The inside is identical to your normal glass fuses although the fuses are sold as ceramic fuses.
The snubber circuit in parallel with triac anodes always allows a leakage current.With these values is about to 6mA.Larger capacitors and lower resistors allows high leakage current.Especially when triac is used as an on/off switch then you might notice your low consumption led lamps to flicker when supposed to be switched off due to that leakage current.
Thanks for sharing this review, I like reviewing stuff before buying it. You said you have not seen it built like that, you never to old to learn, might be a 10yrs Asian boy or girl took a old made controller and improve on it to power and control a toy they have or school work where their teacher give them projects to improve on old equipment. Never underestimate the Chinese way of doing things.
In my experience electronics design engineers in China are generally first class at their job. Most problems arise from the changes made when management tell the production guys to cut costs below the limits needed by the original design.
Thanks for this explanation, I've draw the schematic of the controller myself and was wondering what the purpose was of the bridge rectifier, you made it clear for me!
Thanks Clive. I was just investigating putting a treadmill motor in my mini lathe and you popped up in the recommended. Bonus, because I hadn't seen this video.
Clive's rule of thumb for about 1W/A power dissipation is about on the mark for this device. Here's a table of common UK heating element values versus amps and heat dissipation (plus 4kW). Values are Watts RMS / Amps @240V / Watts heat. See AN2703 for the equation used. 𝟸𝟶𝟶𝟶 𝟾.𝟹 𝟽.𝟶𝟽𝟷𝟼𝟾𝟻𝟶𝟷𝟽 𝟸𝟺𝟶𝟶 𝟷𝟶 𝟾.𝟼𝟻𝟸𝟼𝟾𝟾𝟼𝟾𝟽 𝟹𝟶𝟶𝟶 𝟷𝟸.𝟻 𝟷𝟷.𝟷𝟸𝟾𝟹𝟼𝟶𝟾𝟼 𝟺𝟶𝟶𝟶 𝟷𝟼.7 𝟷𝟻.𝟻𝟹𝟸𝟸𝟻𝟾𝟿𝟸 I have the 'digital' version of this device and will be trying it out tomorow in a plastic unventilated but spacious enclosure at 2kW for about 90 minutes. We'll see if it overheats. I think that little heatsink would benefit from active cooling. The usual disclaimers about the chances of this actually being a genuine ST part apply.
I've dismantled a faulty dimmer that came with some fake Arri light a year ago, the inside schematic is quite similar and the fun facs is that the pcb has the room for the bridge rectifier but is not used, if you are interested i can send you some photos of that circuit. (the Ebay listing is no more available but it was called: As ARRI 300/650/1000W Tungsten Studio Video Spot light+case+Air stands Kit)
I have a 2 kW variant of this triac..use it to control the speed of a 120 volt PM DC motor. It feeds a full wave bridge rectifier with a large run capacitor to help smooth the resultant DC. works but still noisy. need to add a choke ib series to keep from blowing the fuse.
I'm using this very thing to automatically limit a boiler power (from home assistant with esphome) so that it matches pv solar. I considered using a digital potentiometer but there were complications, mainly too much heat dissipation, and maybe live mains on the microcontroller so I ended up using a servo. After 1.5 years of continuous adjustment the pot gave up so I replaced the whole thing wih something very similar but this time detachable thus easily replaceable potentiometer. There are better sollution but this works for me. Needs active cooling.
+bigclivedotcom So if I understand correctly, it doesn't actually lower the voltage? When using a 220/240V incandescent bulb on 110V you can massively extend its lifetime. Will using a dimmer circuit like this have the same result or does the lamp still get 220/240V spikes?
+Ni5ei It lowers the power dissipation of a lamp, so you could use a dimmer to nudge the power down for longer lamp life, but efficiency of the lamp would fall dramatically.
+Ni5ei 5% lower power to an incandescent is generally considered to double the lifetime of the bulb. Any spikes that it might receive from the circuitry would (probably) be much too short in length to actually influence the intensity and therefore does not effect the lifetime.
Since you reviewed this, three years ago now, the only thing different between this and the ones sold today is seemingly the blue protective film, and the screw terminals are marked, and have by he same yellow/orange cover as the power supply
Im in a rabbit hole trying to turn the speed of my die grinder down. I used to be into electronics when i was young, this is very cool. I may try this one out.
I have had a quick read but did not see any comment on this. The reason that glass fuses are not good for high current interuption is that the fuse wire vapourises and can coat the outside of the glass forming another fuse link. The problem with that is the glass keeps it cool so it needs a lot higher current to blow and this will shatter the glass leaving you just the end caps.
Thanks. I learnt something and that's the point. Never knew about the ceramic fuse point either. Really useful one to keep in mind. I often wondered about the sharp edge from triacs on inductive loads especially transformers. I was thinking or experimenting wit ha large triac before a arc welder to drop the power but was worried about the high frequencies generated causing massive heat problems in the welders transformer.
I have a suspicion on that the 4K7 is also for stability, I think it is a part of making the rectifier stable at low voltage, but have you found it out?
in regards with the 4.7k on the snubber .. I believe that to be intentional. If that resistance is too low it would defeat the benefits gained from the rectifier which in it self provides some snubbing.
I think it can also prevent arcing when changing the speed under high load? Being too of a value small might cause the system to become unstable since the bridge rectifier is doing a lot of low end stability.
I open my unit. Same as you have . It gave this 4.7k and when I remove it completely it make a humming inside the unit when I set the knob under 40% and upper 30% . So I think it's a filter for the triac it self Test it under load of heater 220v 1600w
@@NeuronalAxon no I did not because I was not sure if I change it for lower or higher value is the right thing to do since I was need to install it asap in my water heater. I need from you to calculate if this resistance and the Caps can be filter for some frequency ? Because some transistors when they switching on and off they make noise by it self I think
@@NeuronalAxon ok . look what I did now . I just make some calculations for this RC network and I get this information Resistance: 4.7k Capacitance: 100n Frequency oscillating : 50hz Impedance : I got 32 kohm And phase fixing : I got -81.6 Current ammunition : 3>7.8mA So what do you think ? Do you think this a safe guard network for the transistor so it can descharge the capacitance inside it when you try to play quickly in the knop by changing the voltage so quickly and not let the high current make any damages in the transistor ? They say every transistors have an internally C and R virtual and they changing depends on current and voltage and frequency .
So i bought this exact module, I'm planning to use it to power a 2Kw mains water heater element using a 12v 1.5Kw inverter. The 1.5Kw inverter is powered by 4x110ah 12v lead acid batteries. So the plan is the inverter 220v output will go to this module then to the 2Kw water heater, hopefully running the water heater at around 1Kw. Would there be any problems with this arrangement? Thanks!
The dimmer might not like the inverter waveform. You can get low voltage elements for direct use from a battery bank. Using a water heater as a load dump for a solar panel or turbine is a great way to use power above that required to charge the batteries.
@@bigclivedotcom thanks very much for the reply! It's a pure sine wave inverter so hopefully that would help? Yes, I'm actually doing that exact thing! Its a 15L mains water tank which I've modified to also fit a 12v 300w element, that's sealed in with bolts and high temp gasket sealant. So it has two elements in it now. All the water heaters electronics can work on either 12v or 240v and therefore all the thermal safety cut offs should still work regardless of what element is being used. I have dual isolating transfer breakers at either end to ensure 12v and 240v feed can't go to the unit at the same time if a mistake is made! It will mainly be left on 12v and I have a 40a DC relay between the water heater and the battery bank, there is no connection when the relay is closed. The relay is opened/ actuated by a small voltage sensing relay which reads the battery bank voltage. If the battery bank gets above 13.2v then the vsr actuates the 40a relay and dumps the excess charging power from the solar/alternator to the hot water heater. If you're interested I might send you a video/ diagram when it's all put together and you can let me know if I'm about to cause imminent fire, electrocution, explosion!!😂
I should also mention that only the 240v 2000w element is used when 240v ac is supplied. And only the 12v 300w element is used when 12v DC is supplied.
You have a "monster rated" pot in the device since it needs to be rated at mains voltage across the track in series with the 1k and 0.1. Worst case scenario is when the wiper is coming towards the end of the track. It is only protected with the 1k while charging the 0.1. The more up to date ones seem to be using pots designed for audio work which is a little alarming, and possibly getting a little too hot.
Question: Would I be able to use one of these to power the heated build plate of my 3D printer? It's essentially a 1.8 ohm resistor, and I'm not sure if something like this would work. Of course, it would trip a breaker if I turn it up too high, but I'd be running at ~24Vrms and ~400 watts. Does this sound reasonable?
I don't think this will work on 24V~ as it is designed to work with mains voltage. Since your resistive heating element is low voltage and high current (17 A), you can rectify the 24 volts and use a NE555 + mosfet for power regulation.
Sunny Julien Divine No, I don't mean 24V input, I mean 24V RMS OUTPUT. The whole point is that I CAN run the heater on AC, so there is no need for a separate 24V switchmode power supply (which is what most people do). I was thinking that this would be a better solution. I already ordered a similar one, though.
This device is not suitable for your intend as the minimum output voltage is around 33 volts. It would cause a current of over 18 amps and therefore blow the fuse and maybe the SCR if you turn it up accidently. The better solution would be an extra transformer or smps for your heating element.
Sunny Julien Divine Ah, okay. Well, I already bought one, so I guess I'll try it out and see what happens. It was cheap enough that if it dies, I won't be out much.
I'm still an AM user and indeed have trouble with anything using chopped signals, good side of it, I know more about the LEDs build quality this way :)
I think you alluded to the RC network as being more of an EMI filter instead of a snubber and I would agree with that assertion. It will roll off high frequency power spectrum whereas a snubber is designed to limit the possibility of transistor damage due to voltage excursion. A snubberless triac wouldn't need this feature externally.
Hi was just thinking of getting one of those to contr a mot. Transformer in power supply experiment just wander if you think. It would work in this application. Thanks I will like n sub very good video
I have noticed that you sport a sticking plaster or a small cut most times lol, not to distract from your excellent understanding of your presentations.
Great one Clive, I'm in my 60's and have built AC controlers all my life but never seen this set up before ! I think the snubber ressistor is wrong and maybe thats why they were selling them off on Ebay, cheaper to sell them than to repair them.
+Robothut It is not wrong value, it is relatively common for modern TRIAC (it just show someone did homework instead putting random values). Low value of resistor is wrong way in designing rc snubber for TRIAC it will increase turn-on stress which with low value of resistor can damage the TRIAC. Picking components for TRIAC rc snubber is balancing act, but using better TRIAC will lead to greater values of resistor.
+Miloš Lazović Could you point me to a schematic on the Internet where such a high value is used? The purpose of the snubber is to absorb a transient that could exceed the DV/DT rating of the triac. The triac used in this unit is a normal non-snubberless one, so would require a typical snubber combination. The 4700 ohm resistor is going to severely limit the ability of the capacitor to attenuate the transient. Even with a 100 ohm resistor and the capacitor charged up to peak mains voltage the current would be limited to a tiny portion of current not exceeding around 3.5A. That's nothing to a 40A triac with a peak current pulse rating of around 400A. Especially when the capacitor is a mere 100nF.
I am an amateur radio operator and I had a weird experience with a touch lamp. If I transmitted on my radio in the HF bands (3-30MHz) when I unkeyed the radio I'd get a noise that started near the frequency I was on and would slowly drift up in frequency. If I tuned a little up or down I'd get away from the noise so it was like a carrier wave. It turned out to be a touch lamp I had that wasn't even on.
Touch lamps should be illegal. I had horrendous interference all across the HF bands that I eventually tracked down to a touchlamp in a neighbors basement 5 houses down the street.
Hi Clive, Can you please advise how can I test the SCR to determine whether it works correctly? My concern is that with no load and connected to a 220V supply I receive an output of 220V irrespective of the potentiometer position. Will the Volts drop when the Treadmill motor is connected and then only increase as the potentiometer is dialed in? As the Treadmill motor is max 180V I do not want to connect it and then the motor gets blown as the Voltage is not regulated? Regards Hendrik
Great video Clive. SCR/ Tiacs are fascinating things. You might have added how the capacitor manages to allow the dimmer range to be extended by phase shifting the signal to the diac. Always fun to watch your channel
Phew, I'm glad you mentioned Radio Amateurs as I was shouting at the video when your said suppression chokes are not needed these days. Can you do a video on Power Line Transformers and tell people not to use them for exactly the same reason. Cheap Chinese ones won't have the filters in and render thousands of pounds worth of sensitive radio equipment useless.
Is that speed controller suitable for a wood lathe (universal 220V motor) for example? I would like to bypass the 4 speeds pulleys and belt system but my concern is that it could stall under load at slow speeds.
So if I wanted to use this on an induction motor (such as a treadmill motor), what would you suggest I add in order to get good variation of speed from 0 - it's maximum? Thank you very much for your great videos!
actualy on philips diac dimmers you still find the big inductance for filtering... this module is only a chep chinese one that's why is missing... try use it and try do a measuring with the oscilloscope to see how much common noise you get while is working... that's the problem with the cheap things like power supplies ecc... i had cheap led lamps in my lab and while there where on I could not use the oscilloscope...
This also taught me that the dimmer in my lamp must be one of said unstable dimmers; the lamp will suddenly come on after you’ve turned it a bit and will the have dimming function
Thanks for the nice Analysis - I don't like the screw so close to the high voltage track on the backside close to MT1. This could easely short out and put the heatsink at high voltage.
That’s the thing with China; some stuff is really good quality But the overwhelming majority is junk So it gets the bad name It’s hard to know what’s good and bad when everything is a clone
@33Ddg209Ret7 A huge percentage (majority?) of all super high quality tech is made in China (e.g. iPhones, etc), it's just that almost all the super low quality tech is also made in China, and there is a lot more of it.
Dear Clive! I have built a TIG welder from an old stick welder. I have argon post-flow, switch button start and with this 4kW regulator i can regulate my welder below the value allowed by the magnetic shunt. I want to add a pulsed TIG function to my machine utilizing a relay delay timer module (switching between two different resistor values on the 4kW regulator). What currents/Voltages we have on that big potentiometer? Can/should I use snubbers to protect the relay contacts? Thank You very much in advance!
Treat the potentiometer as being live at mains voltage. I'd suggest using half watt resistors. The relay won't be passing much current. I'm surprised the triac has survived such a fierce inductive load.
@@bigclivedotcom Thank YOu very much! In fact, tried it with max power as well and it worked for a short time when the fuse melted. At max power I am measuring a bit above 2kW which around the top for the fuse. Added fan cooling and paste to the triac and it seems it can handle the max load. However pulsing is needed only for thin stainless welds where the high power is around 50A; 1kW at the primary.. Give it a try this weekend.
Hi. There is an effective method without using layers as the rectifier tip passes a sawtooth signal, such as smoothing that signal to eliminate that network interference and canceling out that sound produced by that network interference.
The heat sink screw looks excitingly close to a live track. I'd be trepidacious installing this near ants! If the case is grounded and touching the heat sink, it might be on the wrong side of the fuse as well, but I couldn't really tell from the picture.
Thanks for another great video. I have just got one of these to use on my solar immersion heater control. I see many different suppliers of the same thing but they show completely different connections to what looks like an identical unit. Any input would be appreciated, should not the fuse be on the input?
I intend to use one of those to "dim" down the power use of a 500 W heating element in an RV boiler to about 275-300 W, because I like the boiler element to not take more power then my 455 Wp solar panel can produce. Am I wrong to assume this type of dimmer can reduce (overall) power use of the dimmer/heating element combination ?
The phase angle control requires normal smooth AC and may cause issues with an inverter and undersized solar panel. Using a smaller heating element designed for direct powering from the solar panel would be the most efficient approach.
I wouldn't recommend it. Be VERY careful if playing with MOTs as they are currently the biggest killer of experimenters. Literally like playing with the power supply of the electric chair, and your GFCI/RCD will not detect you getting shocked.
Nice video and explanation. The high voltage clearance around the triac legs looks a bit dodgy (small). Also, I'm not one for trusting the isolation clearances of a cheap carbon pot ( I know they say 750v, but I've seen the guts of pots like that fall to bits on more than one occasion).
And, any RFI generated could also affect those who use over-the-air receivers for home entertainment. It's not just the amateur radio operators who are affected.
The interference is worst in the HF shortwave bands and below. No home entertainment receivers operate that low. Pretty much everything is VHF hi and above now. Unless you still gather around the parlor radio and listen to the evening wireless program in your house.
I have one of these controlling a 2000 Watt element in a pot still. I mounted a small fan on it as the heat sink gets warm and it works for several hours at a time but it preforms very well and is CHEAP. Thanks for explaining how it works. For controlling an element what could better for the money.
Search eBay for 25 in 1 Precicision Screwdriver Repair Tool Set and you'll find some really nice ones for under £5 sets of 32 and 38 also worth looking at
I've been asked to repair a kitchen extractor fan, it draws about 2kw, it's an induction with capacitor single phase motor. It's speed controller has failed . Was wondering if this could be used atleast to drop the speed maybe a third . Do you think the fan motor would overheat as I know this is not the way to slow an induction motor down. What you think
I believe the triac is a "snubberless" type (you mentioned that). The snubberless don't really need a snubber (the word "snubberless" is kind of a self description). The rather high 4.7k resistor is only used to take the "edge" off of the waveform and not trying to really snub.
Clive.. I am trying to build a cheap variac using this device. Great video, but are you intending to show anothr video testing it? Also try to sort out what the trim pot does. Calibrate against known AC supply or st to zero? Hope you can do this. Cheers from New Zealand.
I have myself sometimes used bridge rectifiers different from their 'normal' use because I needed such a particular diode arrangement and they happened to come in a cheap package like that.
Of course the meaning is disguised just seeing this as rectifier symbol in a circuit.
It always makes sense to actually write out the diodes in a schematic to see these kind of hidden (rather interesting in this case) meanings.
Thanks for the teardown and detailed explanations about your findings.
I've always wondered why those diac/triac dimmers can't dim evenly down to complete shut-off. Thanks a ton for explaining that!
I have no background in electrical work and struggle to wrap my head around watts vs amps vs volts (basically anything electrical) but I still binge watch these lol. Great presentation and ability to talk fluidly!
Fluidly? Do you mean "Fluently"?
Gregg Macey nope, fluidly. Like water, he is able to ramble smoothly. Fluidly accurately describes that.
Gregg Macey lol
It's ELECTRONICS not ELECTRICAL!
I bought one of these after watching Clive's video. I added an earth wire to the screw and added a large inductor to the output. Also insulated the top and back of the heatsink because it is VERY close to the case.
I did exactly the same as you as i was concerned about proximity of the heatsink to case screws and added an earth
Assume an inductor on output would be unwise if load was also inductive such as a motor ?
The inductor is to filter the output. This device works the same way as a light dimmer. If you take apart a dimmer switch, it has a coil and a small X capacitor (100n) on the output.
i tested vacuum cleaner universal motors before with this and there were no problems. It handled the inductive load fine.
I also use it to slowly increase the input voltage to SMPS that ive repaired. I can't afford a proper variac.
I use one to control the heating element on my pot still, it works a treat and the controller only reaches 40-45C after 3 hours use @2600W load which I think is acceptable and definitely better than I expected when I was installing a cheap Chinese component.
The great Resistance on the snubber is effecting the time constant of that of the RC configuration (Making the charge time longer). This most probably reduces stress on the capacitor when there is a high inductive load present .
It might be informative to see that power supply connected to an oscilloscope comparing the waveform while using the 4k7 in the snubber to that of a 100 ohm resistor. I wonder how it changes the snubber performance.
would it be worth swapping it out anyway?
Yea that is what I was wondering about. But I trust this schematic compare to what is being pushed out there as 100 ohm.
Also the extra resistor that goes with the potentiometer is in the middle between it and the capacitor. They are typically shows to be above the potentiometer. I wonder if that matters or not. Probably not.
But the whole idea of the bridge rectifier, I think it is a big deal and what has been explained makes lots of sense. Stability matter big time.
I know that without it, any good motor will act as if there is no potentiometer and by pass it and will take off without doing anything.
For what it is worth, a company I used to work for made a whole series of TRIAC based DC motor controllers, and the snubbers were all 47k and 0.01uF (10nF). I never questioned how they got those values, but the circuit and TRIAC worked fine.
Hey Clive I know you've done a computer power supply tear down but I was wondering if you could compare a cheap PSU to a notable good quality one....in terms of quality of components and circuit architecture.
That sounds interesting and I am also in favour of that test. But I know that the brand Seasonic pretty much is the leading producer and that they make most of them. Just look at their warranty of 12 years!
@@sykoteddy Computerparts doesn't have to be crappy, as the requirements rising with every new release of hardware, I still have some 20y old hardware that runs well, even the cheap stuff. Some cheap psus blow up because people tent to run them close to theyr limit. Back than a 250w psu was enough, my 4y old setup runs on 550w psu, the one I build 2y ago already need a 660w psu and a pc with very recent hardware requires at least a 750w. Just as an example, that hardware just ages quick enough.
instablaster...
@@Scootertuner420 Well , in case of PSU's those are probably one of the components that you can not buy a cheap one, nor a expensive, just the wattage you need from a good brand, because very cheap PSU, uses components such as capacitors that are far from what we call a pure component (important for signal conditioning and noise filtering), and what's the problem? Unwanted current spikes, instable voltage, your coomputer will work however motherboard components will suffer, motherboard needs to work with a good PSU so the signal flow will be "smoother" I mean the risk of getting a wrong reading or a exploded cap on mother is lower; Also let's say that you house main fail the chance of a cheap power supply produce a giant current spike and your motherBoard get fried is even higher, I am the guy who bought a cheapier GPU to get a powerfull PSU and guess what nowadays I have a beast gpu with the same PSU chillin cause I know that whatever it happens my PSU will handle the situation while with a cheap your brain will be Please do not burn anything, It is like driving a car with bad tires sooner or later something will happen....
@@Scootertuner420 only 20 years … I still have a UK 101 that I assembled myself in 1980 and that runs fine .. 😂😂😂
I see that the youtube algorithm has chosen this video for this week. I watched it a few years back but that was on my other account so decided to watch it again. I'm pleased to say that, having watched Clive's videos for a several years meant I understood this so much better this time around. :) Learning by osmosis is so much easier than studying.
This video seems to be very active at the moment. I'm not sure why.
@@bigclivedotcom I've noticed it being suggested to me by youtube all week. It seems that you've won the youtube lottery! ;)
Wow! Even though I watched this yesterday it's STILL in my feed! I had to click the three little dots and tell our overlords that I'm not interested in watching it yet again.
I can't admit to understanding all the electronics, but was delighted to hear that this regulator is designed to deliver smoother power at the lower end. My Ryobi drill is very spluttery and rough on slow RPMs and I'm really hoping this will help that. Also, several units of this type have been condemned as death traps, with circuit boards virtually touching unearthed casing, so I'm glad this thing appears to be relatively safe (despite looking hideous and having only one mounting hole on the front). Thanks for the clear and meticulous breakdown.
None of these modules are really up to most safety standards. For better drill control I recommend a good cordless drill.
@@bigclivedotcom Thanks. I'm using my corded drill in a stand. Unfortunately most cordless drills have a pressure-controlled speed trigger which can't be accurately dialled in.
Thank you for mentioning Amateur Radio it’s much appreciated.
Agreed. VA6MEC
@@gmtech68 Yup! WD3WTF
I had to watch the bridge rectifier explanation twice before I got it. (I'm getting old.) But that is quite genius. Thanks for the explanation.
It took me a while to get my head round it too when I first found it.
@@bigclivedotcom Can you give a link to that application note?
The one thing better than watching you "take things to bits", is you explaining what is going on and whether the bits are good or not.
You know so much shit about electronic circuits. You are so good, Clive. And Your Delivery!! Ace, Bloke. ( I am US. I hope "Bloke" is not an insult. I know; "Google it!". I don't think it is an insult. I am rapt when watching and listening to you. Thank You, Clive.
Superb! Like a previous comment I wondered about the poor performance of dimmers at low levels and now I understand why!
i instantly knew the 470k R should have been 100, as i watched your other triac vid 20 mins ago, the 2 together are amazing. i especially like the journey of FBR discovery you personally embarked on in this one. and saying a diac is a bit like a bi-directional zenner made it's effect instantly comprehendible. thanks
Wow glad I found this video, I have one of these laying in a box back in my garage in South Dakota (I am hiding from the winter right now sitting in the Sun in Arizona at this time) It has been laying there now for a couple of years because I really didn't dare hook it up to my wood router. That what I purchased it for, as my 2.5 horse router is a single speed, and I have some huge bits that cannot run at full speed, lest they shake the whole machine apart. These are made for cutting things like chair rails or making cabnit door inserts. If this works right, I can slow the machine down enough to make the cuts without burning up the bits or tearing up the wood when it begins cutting. MIne came with no labels on the terminals but I have taken it apart and pretty much figured out which is which, then made a label for it so I would remember it the next time I dig it out. Thanks a million for explaining how this works and how to wire it up
Well here it is, another year has passed, the regulator is still laying in the box in the garage. The router has not been turned on, in fact my daughter knocked the hell out of my table trying to get an old bicycle out so I could try and sell it, and I have yet to build up the energy to go out and see how much damage has been done. She did it at my request so I can't really blame her. Doc's say I am drugged out on the prescription meds they have been telling me to take every damn day so now the weaning off of narcotic and anti what ever the hell they are anti drugs. My head seems to be clearing, after 3 months of sleeping day and night with only waking hours dedicated to eating and going to the BR. Nice to be awake again, but most of the damn spring and summer have gone and I have done NOTHING. Damn doctors anyhow.
@@JerryEricsson Get well Jerry!
The label is very logic, it's a very efficient way of supplying the sticker for your case, you peel of the blue part, then you peel off the sticker from the blue foil and stick it to your case where the module is installed. By doing it this way they are 100 percent sure that the sticker doesn't get damaged during transport.
I have one of those. Never have developed the guts to hook it up since it came with no documentation, and no markings as to what hooked to what. I did take the cover off, and sort of figured out how to hook it up, the plan was to control my router for my woodshop so I could cut down the speed when needed. That said, it was advertised as 240/110 volt and I was really hoping it would work but after having problems with about every item I got from China that had the duel markings I decided to let it sit in a box out in my garage. Thanks for the info, when the snow is at last gone and the weather warms a bit, I may try hooking her up to my router table and see if it will do the job for me.
Another point to note about fault conditions is the extra solder they have put on some tracks. In fault conditions this will sputter or could even create a vapour cloud which shorts out *everything*. Fault condition testing can be quite fun actually! Place a sheet of blank paper under the board to catch the sputter, then hang it on your wall!
This is why if I'm drawing out a circuit with a bridge rectifier, and it's not immediately obvious how it's being used, I do _not_ draw it as just a "box" like you did. I draw out the full "diode diamond" instead, because that often makes it much easier to see what's going on if people are using a bridge rectifier in an unconventional way (i.e. not actually as a rectifier), which does happen surprisingly often I've found.
I have disassembled several of those controllers, because it's way cheaper to rip them apart for components than to by components and in every one of them it was 100 ohm resistor in snubber circuit, so I am with you. I think that you are right when you say that they have made a mistake.
This is for resistive loads only (Power factor 1) and is triggered from the load, for an inductive load (power factor other than 1) you need to trigger from the line and there are power controller designed as such. Also when triggering from the line you wouldn't need that extra circuitry to stabilize it. Basically this is just a high power light dimmer. BTW the 10 amp fuse will only give you 1200 watts at 120 volts and 2400 watts at 240 volts...
The Chinese have several "standards" like the EU DIN packages. In many cases, the frames are the protective earths. Cheap, fast, safe.
As a radio ham, I don't actually use those bands (2m/70cm personally, I know some HF guys though), but the only thing worse than an unfiltered dimmer is those awful powerline ethernet gadgets. Great way to turn all the house wiring into a giant antenna for digital noise!
73s, 2E0GXE
Powerline units are a ridiculous waste of power too. I had a set which took 16 watts. All day long.
+drkastenbrot Very interesting you mentioned this, I decided to check the pair I own. They do seem to be getting a little more efficient now. It costs me £2.09 pm to run mine with no idle at all. They run at 5.6w on full load. Further reading for those interested here: tinyurl.com/nbb9hmc
+drkastenbrot Yeah, I have a system that can get ethernet from one end of the house to the other with no power usage above normal at all! (it's called a cable lol)
+TheChipmunk2008 I wish I had ethernet handy when we had the floor boards up to fit the central heating, I would have loved to wire up the house properly. I have to make do with powerline, not the favourite solution but the best for the circumstances.
+Ben Thomson Usually even WLAN is more performant than that and it at least stays on its frequency. Those thingies are really just made for the "oh my god WLAN is killing me" guys to make money. In the end you'll have more fun putting a proper cable in your house or moving the computer.
An idea I just had is just putting a directed antenna(like 20dB) on your WLAN. That wouldn't emit any electromagentic waves where it shouldn't and gives a solid connection as long as no one walks through.
73
DO1JOM
Back in the first half of the 1970s I took a standard electrical box and installed a dimmer in it along with a duplex outlet, the original use for it being to subdue the lights on the christmas tree at the time all incandescent. After that this device was used to dim the bedroom lamps, which worked out quite nicely. Unless I wanted to listen to something on AM radio, in which case I had to turn the unit off, or the generated noise made it impossible to use the radio. I have some salvaged ferrites and should probably install one in there, as I don't believe that it came with one installed. So many years later and the thing is still working fine, excepting a bit of mechanical sluggishness in the pot. More recently I offered to build one of these for my lady, and we went out and got what I thought was the same stuff, and I built it. Unfortunately that one displays the exact instability you describe here. Turn it all the way down so that the light pretty much goes out, and then when you want a bit of light you turn it up but nothing happens until you get to a certain point and then it *jumps* to more light than what I'd wanted, at which point you can turn it down a bit. The dimmers in both cases are the sort of thing that might be installed in the wall, as the last place I lived had one for the light over the dining table (which I had to replace when it decided one day to let the smoke out). I haven't really opened them up to see what the differences might be, or why one would exhibit that behavior and the other one didn't. Do you have any thoughts on this?
Your videos are so relaxing. Anyone with a bit of knowledge about schematics and components in general should be able to understand
Great video, interesting application with that bridge rectifier.
I have done many triac designs and have never seen this diode trick. Wow. Interesting!
I have no idea what his videos are about or understand what's going on but I can't stop watching
DITTO
Clear as mud!
@@fulwoodphantom.... but....it never covered the Ground ?! Lol.
Man your videos are great, I think I just powerwatched ten of them. Keep it coming :)
So I find a thing I really would like to find out more about and Clive already did it specially for me 5 years ago it seems 😂 thanks Clive!
I like your comments regarding ceramic fuses. It should be noted, however, that not all ceramic fuses actually have sand inside them. The fuses sold by a particular Australian and New Zealand electronics retailer (known for ripping off Freetronics work) are standard air-filled fuses but have a ceramic case. The inside is identical to your normal glass fuses although the fuses are sold as ceramic fuses.
Congratulations on finally solving the white-balance problem. Good job.
The snubber circuit in parallel with triac anodes always allows a leakage current.With these values is about to 6mA.Larger capacitors and lower resistors allows high leakage current.Especially when triac is used as an on/off switch then you might notice your low consumption led lamps to flicker when supposed to be switched off due to that leakage current.
Thanks for sharing this review, I like reviewing stuff before buying it. You said you have not seen it built like that, you never to old to learn, might be a 10yrs Asian boy or girl took a old made controller and improve on it to power and control a toy they have or school work where their teacher give them projects to improve on old equipment. Never underestimate the Chinese way of doing things.
In my experience electronics design engineers in China are generally first class at their job. Most problems arise from the changes made when management tell the production guys to cut costs below the limits needed by the original design.
I used it on a welding machine and changed the fuse with 20 amps and it works
20 Amp ! you might as well put a 3mm nail, It will work !!!!!
My version that I just bought a couple of weeks ago came with a 20A fuse installed.
Thanks for this explanation, I've draw the schematic of the controller myself and was wondering what the purpose was of the bridge rectifier, you made it clear for me!
Thanks Clive. I was just investigating putting a treadmill motor in my mini lathe and you popped up in the recommended. Bonus, because I hadn't seen this video.
Clive's rule of thumb for about 1W/A power dissipation is about on the mark for this device. Here's a table of common UK heating element values versus amps and heat dissipation (plus 4kW). Values are Watts RMS / Amps @240V / Watts heat. See AN2703 for the equation used.
𝟸𝟶𝟶𝟶 𝟾.𝟹 𝟽.𝟶𝟽𝟷𝟼𝟾𝟻𝟶𝟷𝟽
𝟸𝟺𝟶𝟶 𝟷𝟶 𝟾.𝟼𝟻𝟸𝟼𝟾𝟾𝟼𝟾𝟽
𝟹𝟶𝟶𝟶 𝟷𝟸.𝟻 𝟷𝟷.𝟷𝟸𝟾𝟹𝟼𝟶𝟾𝟼
𝟺𝟶𝟶𝟶 𝟷𝟼.7 𝟷𝟻.𝟻𝟹𝟸𝟸𝟻𝟾𝟿𝟸
I have the 'digital' version of this device and will be trying it out tomorow in a plastic unventilated but spacious enclosure at 2kW for about 90 minutes. We'll see if it overheats. I think that little heatsink would benefit from active cooling. The usual disclaimers about the chances of this actually being a genuine ST part apply.
Why am I even watching this?
I love you Clive!
no plans to plug it in and test it out?
I've been wondering about this topic for three weeks. Thank you!
I've dismantled a faulty dimmer that came with some fake Arri light a year ago, the inside schematic is quite similar and the fun facs is that the pcb has the room for the bridge rectifier but is not used, if you are interested i can send you some photos of that circuit.
(the Ebay listing is no more available but it was called: As ARRI 300/650/1000W Tungsten Studio Video Spot light+case+Air stands Kit)
I have a 2 kW variant of this triac..use it to control the speed of a 120 volt PM DC motor. It feeds a full wave bridge rectifier with a large run capacitor to help smooth the resultant DC. works but still noisy. need to add a choke ib series to keep from blowing the fuse.
I just ordered a SCR and rectifier to control a 130v DC motor with FF 1.0. How did you size the capacitor? I'm not sure how to figure that out.
i think you will find this a SCR not a triac.
Replace this with an triac and double your power and decrease the noise.
I'm using this very thing to automatically limit a boiler power (from home assistant with esphome) so that it matches pv solar. I considered using a digital potentiometer but there were complications, mainly too much heat dissipation, and maybe live mains on the microcontroller so I ended up using a servo. After 1.5 years of continuous adjustment the pot gave up so I replaced the whole thing wih something very similar but this time detachable thus easily replaceable potentiometer. There are better sollution but this works for me. Needs active cooling.
Forgive my ignorance but is this the AC equivalent of a PWM circuit?
+Jamie H Yes. The phase control is similar to the mark space ratio used with DC PWM.
Thanks Clive. Great videos on your channel by the way!
+bigclivedotcom So if I understand correctly, it doesn't actually lower the voltage?
When using a 220/240V incandescent bulb on 110V you can massively extend its lifetime. Will using a dimmer circuit like this have the same result or does the lamp still get 220/240V spikes?
+Ni5ei It lowers the power dissipation of a lamp, so you could use a dimmer to nudge the power down for longer lamp life, but efficiency of the lamp would fall dramatically.
+Ni5ei 5% lower power to an incandescent is generally considered to double the lifetime of the bulb. Any spikes that it might receive from the circuitry would (probably) be much too short in length to actually influence the intensity and therefore does not effect the lifetime.
Since you reviewed this, three years ago now, the only thing different between this and the ones sold today is seemingly the blue protective film, and the screw terminals are marked, and have by he same yellow/orange cover as the power supply
Im in a rabbit hole trying to turn the speed of my die grinder down. I used to be into electronics when i was young, this is very cool. I may try this one out.
I have had a quick read but did not see any comment on this.
The reason that glass fuses are not good for high current interuption is that the fuse wire vapourises and can coat the outside of the glass forming another fuse link. The problem with that is the glass keeps it cool so it needs a lot higher current to blow and this will shatter the glass leaving you just the end caps.
"I'll put that away cause it's quite shite" Mate, as a fellow Scot, that made me chuckle
Thanks. I learnt something and that's the point. Never knew about the ceramic fuse point either. Really useful one to keep in mind.
I often wondered about the sharp edge from triacs on inductive loads especially transformers. I was thinking or experimenting wit ha large triac before a arc welder to drop the power but was worried about the high frequencies generated causing massive heat problems in the welders transformer.
Excellent, thank you for the video.
I have a suspicion on that the 4K7 is also for stability, I think it is a part of making the rectifier stable at low voltage, but have you found it out?
in regards with the 4.7k on the snubber .. I believe that to be intentional. If that resistance is too low it would defeat the benefits gained from the rectifier which in it self provides some snubbing.
I think it can also prevent arcing when changing the speed under high load? Being too of a value small might cause the system to become unstable since the bridge rectifier is doing a lot of low end stability.
I open my unit. Same as you have . It gave this 4.7k and when I remove it completely it make a humming inside the unit when I set the knob under 40% and upper 30% .
So I think it's a filter for the triac it self
Test it under load of heater 220v 1600w
Interesting - did you try different resistor values, too?
@@NeuronalAxon no I did not because I was not sure if I change it for lower or higher value is the right thing to do since I was need to install it asap in my water heater.
I need from you to calculate if this resistance and the Caps can be filter for some frequency ?
Because some transistors when they switching on and off they make noise by it self I think
@@NeuronalAxon ok . look what I did now . I just make some calculations for this RC network and I get this information
Resistance: 4.7k
Capacitance: 100n
Frequency oscillating : 50hz
Impedance : I got 32 kohm
And phase fixing : I got -81.6
Current ammunition : 3>7.8mA
So what do you think ?
Do you think this a safe guard network for the transistor so it can descharge the capacitance inside it when you try to play quickly in the knop by changing the voltage so quickly and not let the high current make any damages in the transistor ?
They say every transistors have an internally C and R virtual and they changing depends on current and voltage and frequency .
@@abeditani8293 - Very interesting - it could be to smooth out rapid changes of the dial, I suppose.
Good informative upload, there Clive , cheers 👍
Radioastronomers hate RF noise as well.
So i bought this exact module, I'm planning to use it to power a 2Kw mains water heater element using a 12v 1.5Kw inverter. The 1.5Kw inverter is powered by 4x110ah 12v lead acid batteries. So the plan is the inverter 220v output will go to this module then to the 2Kw water heater, hopefully running the water heater at around 1Kw. Would there be any problems with this arrangement? Thanks!
The dimmer might not like the inverter waveform. You can get low voltage elements for direct use from a battery bank.
Using a water heater as a load dump for a solar panel or turbine is a great way to use power above that required to charge the batteries.
@@bigclivedotcom thanks very much for the reply! It's a pure sine wave inverter so hopefully that would help?
Yes, I'm actually doing that exact thing! Its a 15L mains water tank which I've modified to also fit a 12v 300w element, that's sealed in with bolts and high temp gasket sealant. So it has two elements in it now.
All the water heaters electronics can work on either 12v or 240v and therefore all the thermal safety cut offs should still work regardless of what element is being used.
I have dual isolating transfer breakers at either end to ensure 12v and 240v feed can't go to the unit at the same time if a mistake is made!
It will mainly be left on 12v and I have a 40a DC relay between the water heater and the battery bank, there is no connection when the relay is closed. The relay is opened/ actuated by a small voltage sensing relay which reads the battery bank voltage. If the battery bank gets above 13.2v then the vsr actuates the 40a relay and dumps the excess charging power from the solar/alternator to the hot water heater.
If you're interested I might send you a video/ diagram when it's all put together and you can let me know if I'm about to cause imminent fire, electrocution, explosion!!😂
I should also mention that only the 240v 2000w element is used when 240v ac is supplied. And only the 12v 300w element is used when 12v DC is supplied.
Was kind of hoping you would test it and see how close to 4kw you would pull before it chooches
You have a "monster rated" pot in the device since it needs to be rated at mains voltage across the track in series with the 1k and 0.1. Worst case scenario is when the wiper is coming towards the end of the track. It is only protected with the 1k while charging the 0.1. The more up to date ones seem to be using pots designed for audio work which is a little alarming, and possibly getting a little too hot.
Always something to learn!
...better than many circuits you've reverse engineered, but 4kW with a 10A fuse...riiiiiight! Thanks BC and cheers KA1RBP
I basically spent my whole Saturday watching your videos, no regrets.
Question: Would I be able to use one of these to power the heated build plate of my 3D printer? It's essentially a 1.8 ohm resistor, and I'm not sure if something like this would work.
Of course, it would trip a breaker if I turn it up too high, but I'd be running at ~24Vrms and ~400 watts. Does this sound reasonable?
I don't think this will work on 24V~ as it is designed to work with mains voltage.
Since your resistive heating element is low voltage and high current (17 A), you can rectify the 24 volts and use a NE555 + mosfet for power regulation.
Sunny Julien Divine
No, I don't mean 24V input, I mean 24V RMS OUTPUT. The whole point is that I CAN run the heater on AC, so there is no need for a separate 24V switchmode power supply (which is what most people do). I was thinking that this would be a better solution. I already ordered a similar one, though.
This device is not suitable for your intend as the minimum output voltage is around 33 volts. It would cause a current of over 18 amps and therefore blow the fuse and maybe the SCR if you turn it up accidently. The better solution would be an extra transformer or smps for your heating element.
Look at 15:04 then you will understand why using this on 24V is not a good idea.
Sunny Julien Divine
Ah, okay. Well, I already bought one, so I guess I'll try it out and see what happens. It was cheap enough that if it dies, I won't be out much.
I'm still an AM user and indeed have trouble with anything using chopped signals, good side of it, I know more about the LEDs build quality this way :)
I think you alluded to the RC network as being more of an EMI filter instead of a snubber and I would agree with that assertion. It will roll off high frequency power spectrum whereas a snubber is designed to limit the possibility of transistor damage due to voltage excursion. A snubberless triac wouldn't need this feature externally.
Hi was just thinking of getting one of those to contr a mot. Transformer in power supply experiment just wander if you think. It would work in this application. Thanks I will like n sub very good video
I have noticed that you sport a sticking plaster or a small cut most times lol, not to distract from your excellent understanding of your presentations.
Great one Clive, I'm in my 60's and have built AC controlers all my life but never seen this set up before ! I think the snubber ressistor is wrong and maybe thats why they were selling them off on Ebay, cheaper to sell them than to repair them.
+Robothut It is not wrong value, it is relatively common for modern TRIAC (it just show someone did homework instead putting random values). Low value of resistor is wrong way in designing rc snubber for TRIAC it will increase turn-on stress which with low value of resistor can damage the TRIAC.
Picking components for TRIAC rc snubber is balancing act, but using better TRIAC will lead to greater values of resistor.
+Miloš Lazović Could you point me to a schematic on the Internet where such a high value is used? The purpose of the snubber is to absorb a transient that could exceed the DV/DT rating of the triac. The triac used in this unit is a normal non-snubberless one, so would require a typical snubber combination. The 4700 ohm resistor is going to severely limit the ability of the capacitor to attenuate the transient.
Even with a 100 ohm resistor and the capacitor charged up to peak mains voltage the current would be limited to a tiny portion of current not exceeding around 3.5A. That's nothing to a 40A triac with a peak current pulse rating of around 400A. Especially when the capacitor is a mere 100nF.
bigclivedotcom
first that pop on my mind is ST AN437, and you will see why they use high value of resistor and why low values are not desirable
bigclivedotcom
capacitor volt 100nf and 150nf
Miloš Lazović ñ
The bridge rectifier reduces hysteresis on the potentiometer by firing the triac with a pulse of consistent polarity.
I am an amateur radio operator and I had a weird experience with a touch lamp. If I transmitted on my radio in the HF bands (3-30MHz) when I unkeyed the radio I'd get a noise that started near the frequency I was on and would slowly drift up in frequency. If I tuned a little up or down I'd get away from the noise so it was like a carrier wave. It turned out to be a touch lamp I had that wasn't even on.
Touch lamps should be illegal. I had horrendous interference all across the HF bands that I eventually tracked down to a touchlamp in a neighbors basement 5 houses down the street.
Hey Clive, have you tested yours? Just bought one. Tested it out, and it works beautifully.
Hi Clive,
Can you please advise how can I test the SCR to determine whether it works correctly? My concern is that with no load and connected to a 220V supply I receive an output of 220V irrespective of the potentiometer position.
Will the Volts drop when the Treadmill motor is connected and then only increase as the potentiometer is dialed in?
As the Treadmill motor is max 180V I do not want to connect it and then the motor gets blown as the Voltage is not regulated?
Regards
Hendrik
Great video Clive. SCR/ Tiacs are fascinating things. You might have added how the capacitor manages to allow the dimmer range to be extended by phase shifting the signal to the diac. Always fun to watch your channel
Phew, I'm glad you mentioned Radio Amateurs as I was shouting at the video when your said suppression chokes are not needed these days. Can you do a video on Power Line Transformers and tell people not to use them for exactly the same reason. Cheap Chinese ones won't have the filters in and render thousands of pounds worth of sensitive radio equipment useless.
Is that speed controller suitable for a wood lathe (universal 220V motor) for example? I would like to bypass the 4 speeds pulleys and belt system but my concern is that it could stall under load at slow speeds.
So if I wanted to use this on an induction motor (such as a treadmill motor), what would you suggest I add in order to get good variation of speed from 0 - it's maximum?
Thank you very much for your great videos!
I tested with the inductive motor of air fan and angle phase triacs does not work at all.
is it possible to design the same thing with 3 phase power supply?
Just bought one today from Amazon...I need for my meat grinder machine to slow down the speed when I'm making sausage next month before Christmas 😏
Indeed friend, i allways use 47ohm in the snubb
actualy on philips diac dimmers you still find the big inductance for filtering... this module is only a chep chinese one that's why is missing... try use it and try do a measuring with the oscilloscope to see how much common noise you get while is working... that's the problem with the cheap things like power supplies ecc... i had cheap led lamps in my lab and while there where on I could not use the oscilloscope...
This also taught me that the dimmer in my lamp must be one of said unstable dimmers; the lamp will suddenly come on after you’ve turned it a bit and will the have dimming function
Thanks for the nice Analysis - I don't like the screw so close to the high voltage track on the backside close to MT1. This could easely short out and put the heatsink at high voltage.
Sometimes cheap Chinese generic products are truly good quality.
Usually, because they don't know where they can safely cut corners and still have it working.
That’s the thing with China; some stuff is really good quality
But the overwhelming majority is junk
So it gets the bad name
It’s hard to know what’s good and bad when everything is a clone
Ha, geiiiiiiiiiiiiiiiiiiii
@33Ddg209Ret7 A huge percentage (majority?) of all super high quality tech is made in China (e.g. iPhones, etc), it's just that almost all the super low quality tech is also made in China, and there is a lot more of it.
@33Ddg209Ret7 iPhone much?
Dear Clive! I have built a TIG welder from an old stick welder. I have argon post-flow, switch button start and with this 4kW regulator i can regulate my welder below the value allowed by the magnetic shunt. I want to add a pulsed TIG function to my machine utilizing a relay delay timer module (switching between two different resistor values on the 4kW regulator). What currents/Voltages we have on that big potentiometer? Can/should I use snubbers to protect the relay contacts? Thank You very much in advance!
Treat the potentiometer as being live at mains voltage. I'd suggest using half watt resistors. The relay won't be passing much current.
I'm surprised the triac has survived such a fierce inductive load.
@@bigclivedotcom Thank YOu very much! In fact, tried it with max power as well and it worked for a short time when the fuse melted. At max power I am measuring a bit above 2kW which around the top for the fuse. Added fan cooling and paste to the triac and it seems it can handle the max load. However pulsing is needed only for thin stainless welds where the high power is around 50A; 1kW at the primary.. Give it a try this weekend.
Hi. There is an effective method without using layers as the rectifier tip passes a sawtooth signal, such as smoothing that signal to eliminate that network interference and canceling out that sound produced by that network interference.
The heat sink screw looks excitingly close to a live track. I'd be trepidacious installing this near ants! If the case is grounded and touching the heat sink, it might be on the wrong side of the fuse as well, but I couldn't really tell from the picture.
Thanks for another great video. I have just got one of these to use on my solar immersion heater control. I see many different suppliers of the same thing but they show completely different connections to what looks like an identical unit. Any input would be appreciated, should not the fuse be on the input?
I intend to use one of those to "dim" down the power use of a 500 W heating element in an RV boiler to about 275-300 W, because I like the boiler element to not take more power then my 455 Wp solar panel can produce.
Am I wrong to assume this type of dimmer can reduce (overall) power use of the dimmer/heating element combination ?
The phase angle control requires normal smooth AC and may cause issues with an inverter and undersized solar panel. Using a smaller heating element designed for direct powering from the solar panel would be the most efficient approach.
Hi do you think this regulator can be used to regulate the primary of a Micro wave transformer ?
Or it Can burn the MOT ?
Thanks 👍
I wouldn't recommend it. Be VERY careful if playing with MOTs as they are currently the biggest killer of experimenters. Literally like playing with the power supply of the electric chair, and your GFCI/RCD will not detect you getting shocked.
@@bigclivedotcom yes you are right about the MOTs.
They are dangerous things.
Nice video and explanation. The high voltage clearance around the triac legs looks a bit dodgy (small). Also, I'm not one for trusting the isolation clearances of a cheap carbon pot ( I know they say 750v, but I've seen the guts of pots like that fall to bits on more than one occasion).
And, any RFI generated could also affect those who use over-the-air receivers for home entertainment. It's not just the amateur radio operators who are affected.
The interference is worst in the HF shortwave bands and below. No home entertainment receivers operate that low. Pretty much everything is VHF hi and above now. Unless you still gather around the parlor radio and listen to the evening wireless program in your house.
I have one of these controlling a 2000 Watt element in a pot still. I mounted a small fan on it as the heat sink gets warm and it works for several hours at a time but it preforms very well and is CHEAP. Thanks for explaining how it works. For controlling an element what could better for the money.
I`ve just bought a similar one for making the ironing water
thanks you sir for your demonstration
Where did you get that amazing screwdriver pen from?
Poundland in the UK. It's often sold as a 9 in 1 or 8 in 1 precision screwdriver set on eBay.
bigclivedotcom Thank you good sir!
Search eBay for
25 in 1 Precicision Screwdriver Repair Tool Set
and you'll find some really nice ones for under £5
sets of 32 and 38 also worth looking at
"Repair Opening Pry Spudger Screwdrivers Tool Kit Set" also worth looking at for prying stuff open when Clive's "hammer and wrench" method fails ;)
Peter D Morrison Awesome, thanks! :)
Very interesting, never seen this bridge rectifying circuit before, genius though. Thank you
I've been asked to repair a kitchen extractor fan, it draws about 2kw, it's an induction with capacitor single phase motor. It's speed controller has failed . Was wondering if this could be used atleast to drop the speed maybe a third . Do you think the fan motor would overheat as I know this is not the way to slow an induction motor down. What you think
I wouldn't use this in a professional application.
@@bigclivedotcom yes I've been looking at decent quality vfd frequency control units
I believe the triac is a "snubberless" type (you mentioned that). The snubberless don't really need a snubber (the word "snubberless" is kind of a self description). The rather high 4.7k resistor is only used to take the "edge" off of the waveform and not trying to really snub.
Sadly, no. The snubberless version of this triac has a suffix of BW.
bigclivedotcom
I see. My bad. The 4.7k must be a mistake.
@@therealjammit yah machine mangwane ke liye mobile number chahie
Thank u very very mutch
Full explnation and schamatic drawing
Clive.. I am trying to build a cheap variac using this device. Great video, but are you intending to show anothr video testing it? Also try to sort out what the trim pot does. Calibrate against known AC supply or st to zero? Hope you can do this. Cheers from New Zealand.