Inside an electronic halogen lamp driver, with schematic
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- เผยแพร่เมื่อ 26 ส.ค. 2024
- It's taken me a while to get around to looking at one of these things. It's a compact electronic power supply that takes mains voltage in and puts out a rough equivalent of 12V AC.
I say rough equivalent, because the output consists of a 100/120Hz modulated high frequency hump with spikes in the region of about 30V that average out to 12V as seen by a simple tungsten load.
LED lamps may tolerate being connected to these things, but may suffer damage. I always recommend using 12V DC LED drivers for your 12V LED lamps.
These units will not operate correctly if under-loaded. They require a minimum current to ensure stable oscillator start up on each half wave. If replacing lamps in ceiling lights with LED and they suddenly start flashing and flickering as a group, there's probably one of these involved. The fix is either to replace one or more of the lamps with tungsten ones again to provide a stable load, or to swap out the power supply for a 12V DC LED driver - which is the best option.
Because these units "ride the sinewave" they are dimmable and also have near unity power factor as the current is spread across the full sinewave.
It's best to avoid using these electronic transformers on the same circuits as traditional magnetic ones, as the switch-off voltage spike from the transformers may damage them. It's also best to avoid placing them where they will be covered with thermal insulation, as heat is an issue. They have a history of going bang. In the long term, a traditional properly rated core and coil transformer will outlast these electronic supplies by a huge margin.
The start up circuitry in this unit is odd. It looks like it relies on the rising positive voltage to pass a controlled pulse of current through the 10nF capacitor when the diac triggers, and then relies on the low impedance of the start transistors base circuit to avoid accidental triggering with noise.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.co...
This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty.
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I learn so much practical electronics from you. I’d never even get halfway to working out how this circuit works.
I agree, he's very knowledgeable and does well explaining everything imo.
Agreed.
I find his voice very soothing.. relaxing.. easy to listen to for hours.
I love the way you broke out the rectifying diodes in the schematic, i'm stealing that.
Thank you for your every video. Since I started watching your channel (and Louis Rossmann) I've learned a TON. Before, I was quite anxious to component level repairs - now I do lots of it, diagnosing problems, detecting faults, following my typical approach - even if it's not really worth it, I'll do it anyway :D
When I started my work in maintenance department at my company, there was a lot of automation equipment no longer functioning properly, being instead operated manually. Timer relays for lights, phase sequence relays, stuff like this. After watching your videos, I started to understand principles of capacitive power supplies. Now I brought most of it back to life thanks to you. Granted, I could've just buy new components and replace them, but where's the fun? Also, replacing them would mean utilisation of old parts, so you essentially prevented generating of more electrowaste :)
Thank you, Clive! Greetings from Poland!
You have provided me years of enjoyment in your videos. Your the only reverse engineer I know on TH-cam. which makes you the best!honestly I have no words of improvements.and if you dropped off youtube I’d cry.
Just thought you needed to know that.
AVE does quite a good RE video.
DiodeGoneWild is also excellent, he knows a lot.
You forgot to mention that the main advantage to the electronic drivers is their efficiency compared to traditional transformers.
And thumbs up for a CFL video.
Would love to see some tear downs and RE of the different types of Fluorescent light fitting ballasts
@Dave Micolichek Doesn't really matter how efficient the transformer is if you use it to drive something that wastes 95% of the power as heat. A 99% efficient transformer with a 100W load will waste the same power as a 90% efficient driver with a 10W load. Incandescent bulbs are atrociously inefficient and the fact we allowed them to keep existing as long as they did when we had fluorescent lights is a disgrace.
@Dave Micolichek That's incorrect. High frequency switch mode power supplies are far more efficient. They may last longer, but are more expensive to buy and operate. SMPS are used in virtually all modern electronics for good reason.
Chris W - the efficiency of a conventional transformer depends on its construction, the quality of materials and it’s size. Good quality conventional transformers can have a full load efficiency between 95% to 98.5%. Show me a cheap switching power supply that can do that...
@@Mark1024MAK A cheap 60 Hz power transformer is not going to be 95% efficient either. Good SMPS are 95% efficient at full load. For DC regulated supplies, the advantage goes to SMPS hands down. A 60Hz transformer supply is around 40% efficient with linear regulation. A boost or buck converter can be used to increase that, but thats switching technology and if you're going to use switching, a full SMPS topology is best. I haven't seen a 60Hz transformer in professional video equipment in over ten years.
I love your videos! The old school "pen and paper" method is priceless. It also gives you the ability to produce a video much quicker, and you still get the point/information across, rather than spending more time doing all the fancy graphics that are not so important in my opinion. I love it! Keep it up!
Couldn’t agree more!
I like the capacitor arrangement in this version. It makes for a quick start as the voltage over the DIAC increases immediately with the input rising. The resistor in parallel just ensures the cap is discharged again.
But indeed, spike sensitivity...
My Fluorescent tube electronic driver went the other day. I opened up and saw the two small electrolytic capacitors are dead (swollen top).
I remember my 2nd house having electronic drivers for the living room halogen lights (hated using those things!! Rented property sucks when they put crap like that in!) and, yep, they went bang, under the floor of the room above, making it smell really nice in what was then my bedroom... :S
I hate it when people seal these things off in inaccessible areas.
@@uK8cvPAq It’s probably illegal, too…
Your printer is amazing your prints look so real
Timsalt3100 It‘s not the tool. It‘s the carpenter.
@Mai Mariarti I may remember he talked about an epson with ink tanks. Could be wrong...
@Mai Mariarti The ink tank printers are very cheap to run. £30 for 6000 prints ... approx.
@Mai Mariarti. Clive mentioned the printer in one of his earlier videos, I'll find a link for you... Give me a bit of time, my granny just passed, so I am busy arranging funeral stuff 😢
@Mai Mariarti He uses an ink printer that has been modified with a continuous ink supply system (CISS). I use an Epson EcoTank that does much the same.
I think your lighting technology videos are your best. Your years of practical experience with lighting enables you to make very insightful comments about how the technology actually works in use. These videos are why I subscribed, and also inspired my design of a light probe to measure lighting output waveforms. Thank you.
Talking about this type of device making a good radio jammer, my first audio amplifier was very good at picking up radio Moscow world service...
For us it was the infamous Radio Peking. I do not know what was the transmitter power, it it was good enough to be picked up by a no transistor single diode radio (no power needed to hear)
with all the effing graboids idk how you have time to even listen to a radio
Was it a Clive Sinclair one by any chance? DC-100Khz... lol!
"Wonder what all these holes are for in the enclosure. Oh well."
> Sticks "OK-QC" sticker over as many ventilation holes as possible, instead of the end panel that's solid.
Never change, china.
Just like the PAT tester plonks nice lovely layers of tested paper stickers over ventilation holes and on plug top power supply units.
Interesting stuff ... having done a large halogen to led swap I remember the issue about not having enough load to keep a circuit active, but your comments about the rough waveform probably explains the high dropout rate. Fortunately the power savings were massive compared to the cost of the bulbs so nobody even thought it odd. Thx Clive!
Thanks for explaining this. I took one of these out of a vintage makeup lamp. It has a large capacitor and inductor for smoothing and two 1N diodes where the diac would be. I didn’t know why they convert AC to DC back to AC again, but then I learned about the need for feedback, isolation, and dimming. I enjoyed your explanation of the double crossover circuit. Now know there isn’t much use outside of driving a halogen bulb. Maybe it is useful for parts!
Please do take a CFL driver apart
I think the resistor/capacitor/diac combination in the first one essentially does the same thing. The resistor helps trickle some current around the capacitor on the rising edge of the rectified wave to keep a voltage bias across the diac so it will trigger. Once triggered, it connects the lower side of the 10nF capacitor to the base of the lower transistor, and then ground, which begins to charge the capacitor and provide a trigger pulse to the lower transistor to turn it on. Once the capacitor has charged, the current pulse ceases, but at that point the feedback network will have taken over and begin oscillating. Theoretically it saves them a diode since the 18k should keep the lower side of the capacitor hovering about the midpoint of the switching waveform, and keep the diac off until the end of the rectified wave at which point it will discharge thru the 360kOhm resistor, if Im reading it right.
It does not discharge the capacitors in its HF half-cycle. The driver transformer core saturates first, and that makes the transistor base current stop.
@Dave Micolichek Core saturation will cause the transformer coupling to vanish, as the magnetic field strength can no longer change. Primary current will no longer be transformed.
Noisy but interesting circuit. Thank you Clive !
Classic Resonant supply Topology . Pretty cool use of the design
I saw the waveforms and my first thought was of the Arctic Monkey's video for "Do I wanna know?"
"If this feeling flows both ways?"
As a child/teenager, I had this compact radio that was somehow amazing at finding CFLs.
At some point, it beautifully transmitted a sound best described as "fffFFFINK". No idea if that was a CFL PSU transmitting its last good bye or aliens.
Very nice to see a Swiss vintage Knobel Transformer. I did not expect to see any outside in UK or EU.
Hey Clive. When I was probably about 12 or so, i remember finding an old desk at the curb with a halogen light setup. I actually hooked up the transformer to a TV flyback and to my surprise it drove it beautifully! I dont think I've seen anyone on TH-cam trying it out.
I used a little cold cathode transformer across the halogen lamp and it drove a tube OK.
Just as I was going to mess with a couple of these that I have, Clive does a video on it. Weird timeline.
Some years ago I got home from a tour, and discovered a small lighting fixture in my gear. I had no idea where it came from, so I couldn't return it. So I stuck a red gel over it and used it to illuminate equipment racks under my mixing desk. When it quit working I figured it was mine now, so I took it apart. It was just a 120-12V transformer and a 12V PAR lamp. I guess with so many speculators driving up copper prices, it's actually cheaper to use all that circuirty.
Copper isn’t particularly cheap. It’s electro-refined, after all. And it’s heavy, along with all the iron that goes into transformers, so transporting the raw material and then finished goods costs more than the switching counterparts. Everyone’s boitching about speculators driving up copper prices whereas the reality has a bit more detail to it. All those “simple solution” approaches are necessarily almost always half wrong - complex systems like supply chains can be rarely described accurately via such gross oversimplifications.
In any case, good switching supplies can be made and are available. Just because maybe to big box store or the chain home improvement store doesn’t carry them is not their fault. The masses buy shit, so shit is what’s sold, but that doesn’t mean that everything brown is automatically shit just because what you see on the shelves is all brown.
it's a self oscillating half h-bridge! that is cool.
It's looking like a electronic CFL circuit with push-pull / half bridge configuration.
That's funny. I recently replaced halogen lamps with LED lamps and ran into the minimum power requirement. The lamps worked but the driver hummed audibly. I replaced it with an LED driver. I was actually considering sending the old one to you because I was interested in why it had a minimum load. Coincidences :->
I was browsing the old bowl tech forums when I saw a familiar name. Crazy small world. I was active on there quite a long time ago but still work in the bowling industry.
I think I remember your name from that forum. I find pinsetters fascinating.
@@user-gx6jb6wc5g I was looking up if anyone had been able to use a different camera on a specific scoring system and just happened to notice a familiar name talking about it also. Need anything bowling related hit me up.
I recall the big heavy transformers I tinkered with as a boy, not realizing that the ones I bought or salvaged were the last of their kind, pretty much. Took home the biggest when we sold the parents’ house before they died. Now it’s all tiny ones running at high frequencies...
And that’s a good thing. Just think of how much material and other resources it took to make all those heavy old-style electronics. I’m glad our PCs don’t weigh 20 kilograms anymore.
You can actually use these supplies as cheap DC sources by rectifying with high speed schottky diode in a "Full Bridge Rectifier" (half bridge wouldn't work) configuration. It is genuinely amazing that they do pack a big punch in such a small footprint, usually 60w in this tiny case.
I measured a 65 VS unit made by Ring. A solid looking unit. 20 watt halogen load. 12.2 V rms once a window suiting 48 kHz was found. This also captured a good looking square wave. The odd looking Forth bridge wave was seen. Ring say OF 0.99 !
The RF emissions and susceptibility of this circuit to mains induced spikes both explain why there was a big fat suppression cap across the AC input!
After the CFL lamps were replaced by LEDs, I thought, great! Now we're finally getting rid of that stupid CFL circuit that dies before the tube dies. And then I find that that damned circuit is still around in halogen lights! 😠😠The CFLs have two of those cheap light duty transistors in the TO-92 package. The first unventilated lamp it's screwed into will cause it to overheat and then like you said, go bang. Really lame.
Thanks for the informative video, Clive.
funny you should mention led lights clive, i was at a newly completed job the other day were some twit had fitted these transformers on led lights rather than drivers. needless to say the led's were dead. i can remember the old halogen transformers in the early 90's and they were solid heavy wire wound transformers better than this kak that they produce nowadays.
Funny? When does Clive not mention LED lights?
I thought I would save my company some money by replacing 12 halogen MR16 lamps (in reception area) with LED versions, but I specifically got the LED version that said was compatible with electronic halogen drivers. Well it started out ok, it worked fine until after about 3 months the first LED died, then another, then another. After about a year just over half of them had failed. Each time I replaced the LED, I also replaced the driver with a proper LED driver. All the LED lamps that were on LED drivers never failed.
New subscriber:
xraytonyb gave you high praise and made reference to your channel in his video TH-cam titled "Random Comments - 9-5-2020"
I once tried to add bridge rectifier made from schottky diodes to one with smoothing cap as well, it did not like it one bit and over heated promptly.
Love your explanations, Clive. 🐿️
Big Clive back at his best.
I've been falling behind on your videos as I binge watch tv shows.
All the same, I hope you're doing well, and soon I will binge watch your videos and get caught up. =D
Would it be safe to say that the quality control label applied over the ventilation holes does, in fact, control the quality?
I made a tiny tesla coil with one of these many years ago.Well not a tesla coil I just fed the High frequency ac into a salvaged TV Transformer. It made nice sparks.
I tried a 20-105 W electronic halogen transformer witha 10 W lamp and it worked. If it power a 5 W lamp its lit dimly. The miltimeter cant measure the HF AC output so I used a diode and a capacitor to measure peak voltage. With no load it was about 6 V in 1 direction and about 12 V in the other direction. With a load its about 17 V in both directions.
A fusible resistor. It’s a component which limits inrush current and acts as a fuse.
You know what you have to do now Clive, don't you? We need to see an LED go bang in your next live stream.
I want to see an LED go *BANG!* as well. :-)
Unfortunately they don't go bang ... they just ... stop.
They used to occasionally bang when run without a ballast resistor. I remember my father soldering together a whole pack of random LEDs from RadioShack in the late 1970s and then attaching them to an electric train transformer. One of the LEDs exploded loudly.
@@phoenixdundee And become DED's - Dark Emitting Diodes....
@@phoenixdundee Not always...sometimes they explode quite violently -- but yes, they often just let their supply of magic smoke out (it's rather stinky!) or simply extinguish silently and permanently. But again, some of them do go out with a bang. :-O
Thanks for this vid. I got the flashing issue when I replaced halogen with LED.
I've got a halogen driver and it actually works fine driving a few LED bulbs.
@Dave Micolichek Yes it is.
The tiny switch mode wall warts are such noisy RFI generators, this one must be a monster! Thankfully, halogen lighting is in its twilight (ha ha) years.
they also make decent flyback drivers...
I've had some of the early LED drivers kill radios back when they first came out. I've also had customers install MR16 and G4 LEDs on halogen lamp transformers then wonder what that high pitched screaming noise is.
These are good for driving flyback transformers if you’ve not got a zvs driver available, plus they’re easy to find in skips as no one wants halogen anymore. I wonder how hackable they are to get more than 12v out of them, maybe upwards of 30v if you rewind the transformer (the ones I have all use big toroidal transformers with the secondary easily accessible and very easy to modify/rewind)
Edit: I tried rewinding the secondary of the toroidal with 30 turns of a slightly thinner wire and it worked absolutely amazingly until the transistors shorted and everything went pop.. I tried it on a different one with 25 turns and it works amazingly with a 7 turn primary on the flyback. I’ll do a video on it at some point as it’s a good way to get 10kv (maybe more) for basically free!
Oops.. Ive killed the other one now. I guess I’ll have to have a rummage in the skip at work tomorrow 😁. Needs to be cooled in oil or maybe a big fan as it got very hot and once again the transistors died and caused a cascade of pops 🤦🏻♂️😂
They seem to be so well balanced that the "wrong" load can cause issues. I have however used one to run a neon ring around a standard tungsten downlight, by using a capacitor in series with a step up transformer.
@@user-gx6jb6wc5g I got another driver, yt deleted my comment with the link so you’ll just have to look at my most recent vid. It’s not as good as the other one sadly as this driver has current limiting so it just cuts out at like 140v in from my variac. The other ones I had (before they popped) made a nice white hot arc with a lot of 100hz ripple as no smoothing, this one it’s still there but not as much as the others.
It would be great if you would have give the number of windings of both the transformer and the feedback coil. :)
Clive, could you do the same for what's in a high frequency electronic fluorescent tube ballast?
Interesting wave form. Curious the power factor of the other more substantial inductive driver.
It looks like amplitude modulation of a HF signal by mains power.
@Leonel Yser By being a Patreon supporter and, in exchange for paying Clive a monthly stipend of a few dollars, getting the chance to watch this and other videos early.
@Leonel Yser Highly recommend becoming a Patreon supporter!
You can connect a flyback transformer to the driver and make a high voltage supply, im gonna make, its kind of like a ZVS driver ⚡
Try connecting a copper coil in the output of the halogen driver and put a piece of iron in the coil i think it would cause the iron to heat up
QC sticker is a classic.
Good to see "CliveCad".....
Have you seen these in 6 V and 24 V verisons? They sometimes pop up on online sales, 6 and 24 V halogen downlights seem much less common than 12 V ones. 32, 36, 42 and 48 V spotlights are so uncommon that even the classic iron core 50 Hz transformer is hard to find.
It might be viable to rewind the outer secondary on the toroidal types for a custom voltage.
Where would these be used? Most of the halogen bulbs over here just connect right to the 120vac mains.
There were 12V Halogens, quite trendy for a while.
See here:
www.brewstersbatteries.co.uk/catalog/premierrl1205h12v5wmr11halogen-p-575.html
The higher voltage halogen lamps are less robust, less efficient and can explode when they fail. Especially on 240V.
@@user-gx6jb6wc5g I once saw an old project online where somebody put 20 low voltage 12v halogen bulbs in series to run directly off of 240v. I thought it was a neat project.
I'm sure you know what website this was on :)
@@eDoc2020 Sadly I can't use my deadly chandelier here. The ceiling is too low.
Original ST application note for those interested:
www.st.com/resource/en/application_note/cd00003902-electronic-transformer-for-a-12v-halogen-lamp-stmicroelectronics.pdf
I wonder if you could get it to print on the other side of the paper. and then cut it out make it look like an actual circuit board just flip the paper over.
Please am looking for an alternative to power halogen lamp inside microscope
Very interesting. Super !!
I would have been surprised if that *didn't* spew radio interference - that waveform looks like a typical over-modulated AM radio signal. Probably puts mains frequency noise across the entire AM band.
I just saw something on ebay you might be interested in, its a 1kV megger/insulation tester that sells for 15 quid brand new, model number BM500A
I have one here. The problem with using it in the UK is that the red tape brigade would frown on it for not ticking their boxes.
"ridiculous frequencies... 30kHz..." bwahahaha!
(ham radio guy here)
At least the second harmonic is good for annoying teenagers and people like me nearing their 40s that can still hear all the way up to 18ish khz.
I went for an interview at a company named RF Microdevices a couple decades ago. They referred to 100 MHz as "essentially DC."
@@sivalley You mean subharmonic. The second harmonic of 30kHz is 60kHz.
@@misterhat5823 durn typo! You got me Mister Hat! How is Mrs. Garrison and Mr. Stick? 😄
What’s the advantage of this over a 12v SMPS?
Dimmable and very high current in a small space.
bigclivedotcom Thanks. I get the dimmable bit but why higher current?
@@michaelfisher9671 No smoothing or regulation required.
@@user-gx6jb6wc5g Thanks for that.
Cheap
Hi Clive, is there any way of getting into contact with you other than TH-cam comments as I would like to send you a power supply I have for my iRobot Scooba, it’s an American 120v input and I mistakenly didn’t use a 240v step down transformer when plugging it in, lots of yellow capacitor urine everywhere. I was wondering if there would be anyway to step 240v down directly inside of the power supply to 120v and then put it back out onto the power supply’s main board.
"Operates at ridiculous frequencies of 30Khz" as a RF guy.... "Ridiculous" is some place above 60 Ghz because that is the limit of the spectrum analyses I have access to goes.
60GHz being a particularly interesting frequency. (Oxygen attenuation).
@@user-gx6jb6wc5g the crazy High stuff is what you find in military Electronics I think that they top out at 110ghz
@@user-gx6jb6wc5g Yep. 60GHz absorption is what radio astronomers can use to look for oxygen :)
Ah. It's already up.
Nasty, but interesting too!
around 40 Khz output frequency
please make a video about CFL drivers with schematic
I replaced the halogen lamps in our kitchen track-light with LEDs - it didn't end well.
I would like to buy drivers
Are you sure the transistor stays on until the capacitor discharges? It looks almost like a blocking oscillator where the feedback rapidly changes polarity when the transformer core saturates.
My microscope has a driver for a 30W 6V halogen bulb. When I turned on the light it came on, and then I switched it off and on again, and now it won’t turn on anymore. It’s not the fuse of bulb. Are there certain parts within these halogen drivers that tend to fail? I wonder if it is typically easy to repair.
It might be worth checking the switch is working and all connections. If they are good and you suspect the power supply then it might be viable to replace it, or swap the power supply for a plug-in one and switch to an LED bulb if it's the reflector type.
What would happen if a 400V electrolytic capacitor was added to the rectified mains DC. Would the output be less "like a string of beads" or would the transistors go bang. Would adding an LC filter to the spikey 12V AC output make any difference to the high voltage spikes.
That's what compact fluorescent lamps do. If it was done to this unit the output voltage would be higher and it would not be dimmable.
circuit looked really familiar, you think a smd version would be as loud?
Very likely, the noisiness of the circuit comes from how it operates, not from using through-hole technology.
@@Agent24Electronics my thinking was maybe the smaller components would have less of an effect, hopefully being better made, or made differently from their larger counterparts
Who else thinks Big Clive should make some ASMR videos just for shits and giggles? masticating noises alert!!🤣🤣
Whenever I hear 'Bridge rectifier', I either hear AvE's Rectumfrier, or with echo, "FULL BRIDGE RECTIFIER" Electroboom style with flowing monobrow.
What does that spiky waveform sound like? Would there be a way to generate it with lower voltages and/or without the risk of the circuit blowing up?
Hi
Is the little transformer in the PCB an ordinary 50/60 Hz or it workes on higher frequency?
Waiting for your highly informative answer.
It's custom wound for higher frequency.
@@user-gx6jb6wc5g
Thank you so much for your reply.
Clive.. Why the circuitry with electronics and not just a transformer if it's just a halogen? What's the advantage?
Ignore. Just got to the bit where you explained it. (Impatient twat I am)
Halogen bulbs require a driver? 🤔
Well, the ones that run at 12 volts need a way to get that low voltage, and without an old-fashioned 50/60Hz transformer I guess that means a driver...
@@markiangooley yeah I later got to know that this is a Step down constant voltage SMPS regulator.
@@pravardhanus This is actually an unregulated SMPS, the output voltage is far from constant. Regulation requires more circuitry and would also prevent dimming.
Some of the newer led tape lights. Have the effect of jamming radios in short distance
Must be the cheap driver, not the tape.
@@johndododoe1411 yeah it was the driver. It doesn't work properly anyway had to learn a whole new color code on the remote. The Chinese LED tape lights. Are kind of crappy but functional
@@Michaelc-gn3eg I have an LED strip lamp illuminating my desk (sold as a sewing machine accessory) that has a USB plug (it's plugged into a USB extension cord drunning to my PC). My ham radio transceiver and SDR are directly adjacent, and I can detect no RF noise at any frequency.
@@allenlutins maybe it could just be my particular control unit it has a fault somewhere in the circuit does not work right anymore with the remote. I would pick it up in the am. band. Of the radio frequency. Also In very certain FM frequencies. Especially while the LEDs were dimmed down I'm not sure if they would affect ham radio or CB mine are not USB power they plug into the wall outlet. Could also be in the power supply.
@@Michaelc-gn3eg Switch-mode power supplies that convert AC to DC are radio noisy and that's probably the culprit. The advantage of the LED strip I bought is that it runs right off DC (from USB) - no conversion required.
why don't they just drive the lamp from full wave rectified 12v off the transf secondaru and dispense with the rest?
Because for the equivalent power at 50/60Hz the transformer would have to be much bigger.
I want to know why the halogen bulb even needs a special driver? If it’s got a filament, it’s an incandescent bulb - just pass the right amount of current through it, and watch it light up. What would happen if you just use a capacitive dropper as in some LED night lights?
The 12V lamps pass a high current. They're not suited to capacitive droppers.
bigclivedotcom - Capacitive dropper, here I come! I want flaaames! 😊
“Pass the right amount of current” - yeah, that’s kinda the conundrum here. You can use a capacitive dropper of course. It’ll cost 10x as much as the circuit shown, probably won’t last as long, and if everyone used those, the electric companies would start slamming the charges for lousy power factor on everyone’s bills, too.
This is off topic but I was wondering if anyone knows how to adjust the temp on yihua 939d soldering station?
Clive on the larger versions of these, are all these components just scaled up or does it have extra protection?
Some just scale it up, but most add short circuit protection.
Larger versions can be made cheaper and better performing with slightly more complexity. You can scale up this basic circuit but it’s not terribly wise. Also, today you can have a $0.10 microcontroller running the show in those supplies and it can do a much better job at controlling it all than a raw BJT self-resonant converter.
Yay another video
My tablet corrected my text just before sending. VA and PF
Thank y sir!
It's possible use this for drive a little neon tube at 12v?
For the science can try?
This won't work for that, but you can get 12V neon power supplies.
Thanks again😀
Arghhh! You didn’t draw the Full Bridge Rectifier in a diamond shape! Must be a first in the electronics domain?
It would be interesting to get some HV probes and an isolation transformer and scope things like this?
I have a really early General Electric SCR manual that has the diode bridges drawn this way. 1962 I believe is the publication date. Therefore, I always draw full wave bridges that way. Guess it's the way you learned as a kid.
I remember bying one of these thinking it'll be able to drive 12V LED strip. Guess what!
You fried the LED strip.
@@simontay4851 It didn't even start!
I tried full bridge rectifier on the output, two LED strips in reverse-parallel, shunting the output with a low power 27V bulb, shunting with a resistor. Nothing!
LEDs started display Star Wars movies? 🌟
@@matijakukec4731 It was more like playing Doom3 on a lowest brightness with a monitor turned off.
@@777anarchist 😂😬😅
hi big clive . could you explain how a vw electric power steering system works . i took one apart its very instresting cos it seems to use a brushless 3 phase mlotor some how worked from 12v dc power supply hope can explane this . thanks
I would really like to see a teardown/explanation video on that also! I'm glad they use brushless motors in the VW ones, as steering is pretty important (!) would hate to have it fail because of a brush/commutator mishap!
When it fails you have manual steering yet
Can you explain me the circuit of halogen lamp transformer 220v AC to 12 v Ac . My transformer not giving 12v AC output
If it's an electronic one like this for halogen lighting then it needs a load to work properly. If it's a traditional transformer it may have tripped a thermal safety device if it got hot.
@@user-gx6jb6wc5g ok thanks
@@user-gx6jb6wc5g It is a electronic transformer. That means if I connect 12 v AC load then it will give 12 V AC output.
I have - had - 12v halogen lights in my bathroom. As the bulbs blew, as they do, I replaced then with LEDs, which didn't work. Assumed the drivers had died. Might be they are these, and just wanging some halogens in will have them working again.
I feel rather stupid now 🙂
It's a common thing. It catches a lot of people out.
@@user-gx6jb6wc5g if it is just the bulbs, my brother will kill me - I had him go up into the spider invested loft to make sure the drivers were getting power.
He hates spiders 🤣