Thankfully they had the courtesy to gold plate the hot antenna. I mean, if you are going to take a bite from the mains, good continuity is a must at any amperage!
What most people don't realize is gold is a worse conductor then copper... Only silver is a better conductor then copper. The main reason they coat things in gold is because it does not easily oxidize... Go look it up, it's totally not what you would think
@@youtubeistyrannical1787 "Look it up". Good words. I began studying metallurgy at age 32 when I bought a mill and lathe for my home shop. I'm 54 now and have learned so much about metal that I realize I won't live long enough to learn 50% of what we already know. That said, Silver is my favorite conductor because it reduces arc transfer when breaking high current connections. ;) Steel (in it's many forms) is by far my favorite metal. Gold is for people who want jewelry more than they want a 1000lbs of misc. mixed metals on a rack in the garage.
@@johndododoe1411 Clive mentioned that those 24-bit codes divide into the 20-bit part that is unique (sort of) to one RC unit and preprogrammed in the factory, and the other 4-bit part is for commands themselves. So, the short answer is no, it doesn't seem to allow such operation.
We recently had a safety email go out. One of the pump buildings we have was live. The building itself was live. One of the maintenance guys got a shock off the metal door when trying to open it. The metal parts of the building (i.e. most of the building) were somehow connected to power. Never did hear what was the issue that caused it.
Ran into a live panel enclosure a few years ago while tracking down a repeated server failure. That one was a "hilarious" combination of faults. First was the live wire contacting the shell. Okay, it happens. But that was supposed to be a _branch circuit_ coming _out_ of a breaker - so that circuit was being backfed somewhere. Not okay. This was also a subpanel, so it should have produced a direct ground short and tripped the upstream breaker - ground bus wasn't bonded to the panel. Also not okay. Finally, the panel was right next to a floor sink used to fill (and empty) mop buckets! Technically I suppose our ELV license would have allowed us to repair that, since it was clearly "incidental to and necessary for the licensed work", but no. Just . . . no.
I found a situation like this once at an airport my company was a contractor at. What I had found was that a motorhead for one of the giant sliding hanger doors was replaced, and was causing the issue. The old one was a "2-phase, 220volt" piece and the replacement that someone had installed in it's place was a single phase, 120volt unit. The installer must have realized the issue of not having a neutral wire, and had connected one leg of the 220volt two phase to the live terminal of the unit, and then connected the unit's neutral terminal DIRECTLY to the metal chassis of the building.. 😳 I found the issue by accident as the door was a slider that parted in the middle and had 2 motorheads on it, one for each half, that drove them. I just happened to be servicing them and noticed that the spec plates on them had 2 different voltages listed, and questioned the maintenance staff about it, and they had no issue why. So I started looking into it, and that is what I found. Thankfully there were no accidents from the entire building being used as a neutral conductor, but it certainly could have ended up as an electrocution in the right situation.
Well that's a good thing that they used email and not something useful and immediate like a text message. You definitely want to be sure your employees have to wade through dick enlargement spam in order to find out they shouldn't touch an entire building due to Mr. Electron running rampant through the walls.
clive has acquired a skill that lets him know if a product is designed to kill you or not just by looking at it !!!! Clive !! your the next step of human evolution !!
Electrical engineering, tinkering with odd things.. you can learn that skill too. Just open everything you buy, there are patterns you learn. Any metal parts sticking outside from a plastic case that is connected to mains but not earthed = red flag.
At least it's transmitting in the 433MHz ISM band, I've had some Chinese RF remote devices that transmitted in the DAB radio band causing interference.
After watching you for a few years with general interest, I am actually beginning to not only follow the schematics, but understand the principles. Great video as always!
I bought a 4-button A/B/C/D version with the same F/N switch and telescoping antenna to control an LED swimming pool light. This was an Amazon purchase in the US. It claims a 1 km range and I thought it might be useful to control other things, but when I received it I noticed it didn't have any of the usual FCC markings. It's pretty easy to get a 1 km range if you don't worry about silly things like regulations. Judging by the amount of noise that comes out of my PC speakers when I press the remote buttons half way across the room, I suspect it may transmit more power than FCC 15.231 allows. I measured the frequency to be 433.92 MHz with a cheap Chinese SDR. For some reason one of the buttons had a slightly different frequency than the other three. My receiver looks similar but it does not have an external antenna, so maybe there is no electric shock hazard. Thanks for doing this, Clive. I did my own tear-down of the light but didn't think to open up the remote.
EV1527 is a classic. Very hackable. It has 4 inputs, and every combination of the 4 inputs sends a different code. I've used it in projects to give a dozen or more buttons.
Most of these RF switch/smart switch thingies don’t have enough room in them to maintain the double insulation into the box so I’d always advocate putting them into an enclosure anyway. However, the SMA antenna implies that the antenna could be remoted so it’s a fail from me ;-) Excellent teardown as usual Clive, keep up the great work!
As you mentioned, these are often used to control pumps. It's not uncommon for a pump to be below ground and you wish to control it remotely from above ground. I think they set up the antenna this way so that you could have the relay in a box or chamber below ground, removing that little antenna nub and instead screw on a long cable attached to an external antenna above ground. Still, it wouldn't have taken much to add a removable cap or boot so that the metal isn't normally exposed.
In the US, 433mhz is a licensed amateur radio band, and you do occasionally get some naughty devices from China that use 433mhz instead of an unclicensed band (e.g. 315mhz). They’re not illegal, because they’re so low power, they just don’t work at all if you have an amateur radio operator using the frequency.
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I think, that the 433 MHz band also is used in Germany for amateur radio.
They also don't work when you have many devices in operation in the nearby area. My grandfather eventually ended up in a posh "community living center" for the elderly. He was always an electronics geek and had to take his latest "weather station" with him wherever he went. The temperature/humidity probe was wireless and operated at 433mhz. When he was still in his own home, the sensor had always operated properly, and he never had an issue with the display receiving the signal from it. When he moved into the community living center, he had all kinds of issues with the display losing the signal from the wireless sensor. When he questioned me about the issue he was having, he had the sensor just sitting on the brickwork of the building right outside his window. I decided to help him out, and mount the sensor in it's proper bracket, which stands it off of it's surroundings, thinking this will help with his issue, but about halfway through drilling the holes in the brick to mount it I realized that this probably wasn't the issue when I spotted similar sensors mounted outside of just about EVERY OTHER window on the building. Yep, old people must just like to have their weather stations. His unit did have switches inside to change the channel for the communication between the sensor and the display. I changed his channel to a random combination of switches, and he had no more problems with it.
@@pear7777 everyone can have a little brain fart... it happens to the best of us as well... sometimes when i cook and need to make my sauce tasty, i add honey and mustard and it kicks ass
The tri-state inputs on the back of the remote is so that you can give the remotes different addresses so if you had a lot of them you could make sure they don't overlap.
With the On and Off, clearly, the O is redundant. In Canada, where we have both English and French as official languages, the water taps are either labeled H and C or C and F. I’ve often thought it would make sense for them to be H and F (as opposed to C and C), so each language group would get one “good” letter, and the other as “not the good” letter, or something else bacronymed into the situation (Hot and Frigid as an English example)
The antenna circuit is decidedly odd: It has a loading coil in series (which is redundant if it uses a loaded antenna). And that means that the coax connector is no longer 50 Ohms, so the metal outer is completely redundant and doesn't need to be connected to "Earth" (eg it should have just been left floating). It rather looks to me that the design started life as a 27MHz remote and was clumsily redesigned.
These transmitters with otp codes are pretty nifty. I was surprised recently when I got two identical LED floor lamps, and their remotes didn't operate each other, they had those unique codes. Fortunately with a hacked Sonoff RF bridge I was able to read and reproduce the signals for automation.
Ironically, the external antenna might even make the reception worse. Those little boards are typically tuned at manufacture, so tacking extra conductor on the end without re-trimming might impact the receiver circuit (assuming this module even has the usual trim inductor). I can also see someone deciding that the reception isn't good enough inside their plastic enclosure, so they install a bulkhead SMA pigtail, bringing that diode-to-mains shell out of an ungrounded case.
Yes, found the same with quinetic wireless switches here. They operate at an unknown band, but the antenna is a precise length of wire.... adding wire to it or removing any DRAMATICALLY detunes it
@@Spiderelectron an adblocker is nice on PC but as soon as you watch in the phone app it's ads all over again. Well unless you block ads by blocking them with your DNS server, like do.
Im not certain why it even needs that stubby antenna, other than to make it look cool. Ive used many of this type of unit, and usually that short spiral wire antenna gets TONS of distance.
I have another version of the same remote with 4 buttons for controlling a pool light and changing its color. It doesn't have the external antenna. Still 433 MHz. There is no need for that big 80s-cordless-phone antenna.
The crazy thing is, just yesterday I ordered a 12v remove relay with exactly the same control. The unit I have has one of those little pin connectors so you can move it for different modes. 1 mode is A- on and B- Off. 2nd mode is A- On A- Off B-Nothing. And if you take it out all together its just A-On until released. I am using its bits along with another external relay to make a buzzer to say when power goes off.
Thank you for that info. I've been trying to figure out how that damned jumper worked!!! The Chinglish in the product description on Amazon was no help at all.
I added a DIY antenna extension to a plug-in doorbell from Amazon (UK) and when testing it, never considered for a moment that it would be at mains voltage. Well, a clean pair of underwear later and I was now a LOT more respectful of my dodgy antenna!!
When I saw the thumbnail, I got the impression the device had melted the plastic bulb. I was a bit disappointed when I learned that wasn't the case. But when I heard the word China, my joy returned.
Indeed it was, though the capacitor values were usually a lot higher than 1pF. At least for the older sets that needed Band 1 reception (40 - 70 MHz) the capacitors would typically be 1nF, (or .001 microfarad as it would have been described at the time). These capacitors were also usually shunted by a resistor, typically 2M2, to discharge them.
@@eDoc2020 And many tube radios back in the day. Though they sometimes didn't bother with the capacitor for those too, leaving the chassis connected straight to the line (unpolarized plugs back then, so 50/50 chance to have a live chassis). Even when there was a cap, they almost invariably short over time. Fun stuff.
I bought a $7 SONOFF a few years ago, and really like their design. Upgraded the firmware to run Tasmota. Love it. This is nothing but an old garage door opener chip and easy to hack. Also, the 2W standby power is just ridiculous.
It's possible that the "F" and "N" on the transmitter switch are short for "off" and "on", but since they start with the same letter, they just used the second letter of each word.
@@jkobain I always thought I/O was odd. If "I" means current then what is "O"? If I is a pictogram of a bridged circuit, then O is.... huh a loop? Is I a pictogram and O just stand for "off"? One way or another its a broken abbreviation or metaphor.
@@boulder795 I'm amazed at the number of people I encounter that don't understand this. I guess growing up in the age of the 8-bit microcomputers and learning about binary very early on, it just makes sense to me, where people who have never really dealt with binary are totally confused by it.
I believe so that you can run an antenna cable. For example, imagine this relay is in a chamber deep below ground and you want to control it remotely from above ground. You could then run a conduit for an antenna so you'd be able to receive a signal from above. Still, they could easily have made a removable cover or boot as a safety precaution.
_“This chip isn’t powered until you press the button. Very strange…”_ I don’t really know about this stuff, but isn’t that why/how it draws no current while idle? 🤓🤔🤷♂️
@@bigclivedotcom Maybe that controller doesn't have sleep or low power mode... which is still odd for a mostly battery-operated ASIC... but they solved it with this workaround. It's much more difficult to do this hack on silicone level :)
I'm torn between strange and an old-school brilliant way to save that poor old 9v battery as there is no "idle" state. Other then the slight "parasitic drain" this thing draws next to nothing when the buttons are open. Just enough to cause the battery to leak out in a few years of being lost behind the couch. Reminds me of my first TV clicker, back in 1970's-something. Way to go China, always pushing the curve in engineering advancement
Hey I've been watching your videos for a very long time now and I noticed I've never subscribed wonder how I missed that. Anyway now am in thanks for the very informative content I love them keep them coming.
@21:00 in the video. The use of the PNP transistor in that circuit is not strange. It's quit ingenious actually. What they are doing is making sure that no parasitic/stand-by current is being drawn by the uC, ensuring that the circuit is 100% off when not in use.
I just got a similar unit from Amazon through the Vine programme. The antenna shield on this one is wired directly to neutral, so it's getting a nice PAT fail photo for the one star review.
a low value capacitor in series with both legs on the board to be safe. something like a 100pf or less would be a short at 433mhz but not let through any AC mains.
I was thinking the same but maybe a better solution is to use a small RF transformer. I've seen some of those in the past. They are small and I think in general there is less risk to dielectric brakedown with respect to caps... It's a shame because the circuit seems to be well designed (better than the eBay Chinese electronics average)
Blocking capacitors on the mains to exposed parts used to be a thing. They got nicknamed "death capacitors". Any exposed parts has to be fully insulated. Electronic parts can short, and things get wired up wrong. Nothing should ever be "made safe" by trying to Isolate it with an electronic component in series with the mains.
@@JendaLinda they are earth connected surpression, not connected to the line. No device with any external conductive components or user made connections can be referenced to the incoming line.
@@killcar5nbike2 Look at any USB charger. There's no earth connection. The primary is referenced to mains and it is connected via a small capacitor to the secondary.
Me: picks things up by the antenna. Also me: checks live wires with fingers. Also me: has abnormally high skin resistance. Looks like fun. I somehow want to buy this more.
@@bigclivedotcom Good thing I'm always dehydrated... . Jokes aside; I do take due precautions, only messing with known values. Although as a kid, how I learned of my resistance... I was the kid who put a finger in the light socket, and switch contacts, and plugs... Probably why I got interested in electricity and electronics.
5:10 may not necessarily be mislabeled. If you check continuity between live and neutral, and you still have a load connected such as a light bulb, it will still ring as continuity.
The two amplifiers in the remote are probably also there to reduce harmonics when transmitting. Have you considered using a rtl-sdr dongle to get RF samples? It would be some a trivial to sample and display the bit pattern code. Since this transmitter uses on off AM style you'll be able to see the pattern just by looking at the waveform. I would suggest using the rtl_433 program, it has a feature to use display the raw and demodulated waveform with timing.
I remember when I was an avionics technician in the Navy they told us that even 100mA can be fatal in the right conditions, so 75mA is going to give you a decent shock.
If the zener voltage has a positive temperature coefficient they will tend to balance out. The one with initially lower voltage will conduct more and warm up more, thus reducing the voltage imbalance. It will not balance perfectly, though.
Cut the ground and signal lines to the antenna and put 220pF Y type caps in both paths. It will still work and it will not be a shock hazard anymore. It was a method Phillips use to use in their TVs.
Programming modes for these remote switches are often momentary (single button), continuous (while single button pressed), toggle (single button) and on/off (two buttons). I can't see that momentary would be much use in a switched relay configuration though.
That "little antenna" is a simple RF low pass filter. It not part of the receiving antenna due to too being connected at both ends, and the ground plane surrounds the antenna connection, helping to separate it from the main antenna. Because its unshielded, it can serve as a very weak antenna when the main antenna is disconnected. It can also serve as a loading coil for the antenna due to the antenna is way too short for 400MHz use. Its been years sense I did antenna/RF theory work, so some fine points I may be wrong on.
I wonder how many of these eBay or wish things are factory rejects. Like they made up a batch with the wrong stickers and decided that it was better to just sell them cheap than put on a new sticker or dump them. I've seen it with like chef knives. It's pretty smart.
The two 24V Z diodes are no problem. Above 5V the TC (temperature coefficient) is positive. For 24V the tc is strongly positive, probably around 15mV per K so if one gets hot, the current goes to the other.
Except that semiconductors fail by shorting. Besides, nothing else in this thing in redundant, why just the zeners? They clearly are sharing the load and two 12v zeners in series would be a better idea.
Not bad! Very nice design inside the remote, ensuring that nothing trickles the battery down with its quiescent current. At this point I'd guess the function of the switch is more to prevent accidental button presses rather than help with battery life. As for the antenna (which, as someone has already pointed out, appears to be incorrectly wired to an existing internal antenna), an easy fix would probably be to swap the diode bridge for a half-bridge rectifier. This would ensure the antenna is always referenced to Neutral, which although not ideal, at least won't shock you under normal circumstances.
@@simontay4851 You're right, my bad... A couple of back-to-back 24V zeners strategically placed after the 68 ohm resistor would help, but that'd probably dissipate too much power. Edit: or rather a zener in series with a regular diode.
@@bigclivedotcom Yeah, as I said, not really a proper solution... Still better than guaranteed 300V pk-pk on the exposed part. On the other hand, in case of miswiring you'll get full 600!
to add a few items (which Clive mentions the pick up coil), the RF section: on the receiver side, there appears to be a small "pickup coil" which will allow the thing to be operated without the external antenna connected.. it may have been an after thought to add the external antenna; they COULD have isolated the external shield on the RF connector with a pair of 20 pF ceramic caps to the common of the circuitry and this would have isolated the mains from the exposed metal parts of the antenna circuit.. On the transmitter side: this appears to be a "saw resonator" type RF circuit.. quite similar to a "garage door remote control" though slightly-modified with a buffer amp and external antenna.. the rest is as expected. Overall, from the RF side of things, this is a POOR quality RF link.. I would think this has a effective range of maybe 1000 feet outdoors, 'line of sight' (much less range indoors).
I can (sort of) see the logic in the parallel zeners. If one goes open, you still have one to hold the rail to 24V, otherwise, the voltage might go very high. This would not be the case with series-connected zeners.
Lovely! I love it when we have parts that are easily touchable, that are live at full mains voltage :). In fact, you could add an external antennae to it (which is more powerful/more directional). Would that not make the antennae live?
1a. if you do put the remote into service you will need to isolate the receiver unit such that no one can come in contact with the antenna either by enclosing the receiver module entirely in a plastic enclosure or placing the unit well out of reach of anyone and have plenty of warnings like antenna connector presents a shock hazard disconnect power before adjusting or replacing the antenna. 1b. in theory you could power it from a 24 volt power supply. bypass the dropper to run input directly to the output of the rectifier diode block. then power it from a 24 volt doorbell or hvac transformer. you can get doorbell transformers from your local builder's shop or ebay. hvac control transformer you can get from your local heating and cooling or even plumber shop. if you are lucky and can get access to a house that is marked for demolition you can go through and salvage some of the stuff. 2. the remote uses the ask ook banding. 3. the interference that your hand presents to the antenna of the transmitter is exactly how a theremin works a theremin exploits that interference to control the tone.
Let me clarify some of those abbreviations On the remote F/N is Functional not active / Now functionally active On the output terminals A is Another neutral and N is Not neutral Also ANT is not short for Antenna it is the Auxiliary Neutral Terminal No sure how you could find that confusing.
You know what video I'd really like to see... something demonstrating the issues with these mains referenced exposed metals... something maybe starting with an oscilloscope and ending with some bangs and flashes and maybe a hotdog or two for human finger substitutes ;)
The only reason I can think of for the PNP switch arrangement in the remote is so the input is not pulled above Vcc. With this arrangement the inputs are a diode drop below Vcc (minus Vcesat which shouldn't exceed ~100mV). Using a diode to power the chip puts the inputs above Vcc by one diode drop. A lot of chips gets very upset (and even fail) when an input is driven above Vcc.
Their thinking must be that referencing to neutral is kinda ok for industrial wired in stuff. Not good for portable or residential where getting the hot and neutral swapped is much more likely. Just cutting the ground side of the RF connector and inserting a .01 cap would allow the rf to flow and the AC to not. Seems like a simple mod if you wanted to use one of these to say, control a dust collector in a shop for instance.
Enclosed Mean Well PSUs have mains terminals like that. The annoying thing is that 99% of the time when you get a used one the terminal cover is missing and Mean Well doesn't seem to sell replacements.
It is strange that they didn't just put a small capacitor in series with the antenna connection. That would limit mains frequency current if you touch it to a very low value while letting the RF through. When TVs had circuitry running directly off the mains the aerial inputs had just such capacitors.
That 680v MoV is interesting. If you are about to design capacitive drop power supply look up „ tdk everything for capacitive dropper”, very usefull stuff, also „cap drop offline supply texas instruments” or „AN954 transformerless power supply”
You know, what they could have done is put a y class capacitor in series with that antenna. A couple hundred picofarads should do. Low-frequency AC is mostly stopped by that but RF goes right through it. Additional cost is very low but it's much safer.
that little daniu transistor tester you have can show you the code from remotes like that and tv remotes etc. i wreaked mine by connecting it to a charged capacitor by mistake. Anyway! nice video.
Yet another live item from China lol I bought a set of mains powered lights from China just before Christmas and got a zing off it, 1 diode between you and certain death 😁love your vids mate stay safe and sound in these very uncertain times
23:12... You could remove the PCB antenna connector and solder a similar length of antenna wire as the Transmitter uses to isolate the live Neutral by keeping it inside the box.
To be fair, provided the Live and Neutral have been connected correctly the voltage on the antenna is only -24V so if you get a zap from it then it's your fault for wiring it wrongly.
I found a delightful little DIN rail "panel" relay from china. It "claims" 63A, but I somehow doubt that. It would probably explode if it tried to switch 50A, especially with any kind of inductive load. It does make a rather chunky relay noise when it turns on and off, at least.
Thankfully they had the courtesy to gold plate the hot antenna. I mean, if you are going to take a bite from the mains, good continuity is a must at any amperage!
Holy shit, I love “take a bite of the mains”
@@kaitlyn__L Sarcasm can be difficult to read. I do my best to prevent any confusion
;)
@@greggoog7559 They probably could have just mounted it inside the plastic enclosure ;)
What most people don't realize is gold is a worse conductor then copper... Only silver is a better conductor then copper.
The main reason they coat things in gold is because it does not easily oxidize...
Go look it up, it's totally not what you would think
@@youtubeistyrannical1787 "Look it up". Good words. I began studying metallurgy at age 32 when I bought a mill and lathe for my home shop. I'm 54 now and have learned so much about metal that I realize I won't live long enough to learn 50% of what we already know. That said, Silver is my favorite conductor because it reduces arc transfer when breaking high current connections. ;) Steel (in it's many forms) is by far my favorite metal. Gold is for people who want jewelry more than they want a 1000lbs of misc. mixed metals on a rack in the garage.
"And the remote control simply goes On, and Off."
Actually, the buttons are clearly labeled Activate and Beactivate.
Ahh yes, 🅱️eactivate. Good observation!
Can't the receiver be set to only accept A or B, then another receiver can use the other button for another big thing?
@@johndododoe1411 Clive mentioned that those 24-bit codes divide into the 20-bit part that is unique (sort of) to one RC unit and preprogrammed in the factory, and the other 4-bit part is for commands themselves.
So, the short answer is no, it doesn't seem to allow such operation.
Ah good and Bad
I love the oxymoron of a good portmanteau in the bAM.
We recently had a safety email go out. One of the pump buildings we have was live. The building itself was live. One of the maintenance guys got a shock off the metal door when trying to open it. The metal parts of the building (i.e. most of the building) were somehow connected to power. Never did hear what was the issue that caused it.
That could either have been an unbonded metal frame building, or external equipment finding a current path back to a grounded frame.
Ran into a live panel enclosure a few years ago while tracking down a repeated server failure. That one was a "hilarious" combination of faults.
First was the live wire contacting the shell. Okay, it happens. But that was supposed to be a _branch circuit_ coming _out_ of a breaker - so that circuit was being backfed somewhere. Not okay. This was also a subpanel, so it should have produced a direct ground short and tripped the upstream breaker - ground bus wasn't bonded to the panel. Also not okay. Finally, the panel was right next to a floor sink used to fill (and empty) mop buckets!
Technically I suppose our ELV license would have allowed us to repair that, since it was clearly "incidental to and necessary for the licensed work", but no. Just . . . no.
Sounds like a pretty cool place to work: death is around every corner and around every metal bannister
I found a situation like this once at an airport my company was a contractor at.
What I had found was that a motorhead for one of the giant sliding hanger doors was replaced, and was causing the issue. The old one was a "2-phase, 220volt" piece and the replacement that someone had installed in it's place was a single phase, 120volt unit. The installer must have realized the issue of not having a neutral wire, and had connected one leg of the 220volt two phase to the live terminal of the unit, and then connected the unit's neutral terminal DIRECTLY to the metal chassis of the building.. 😳
I found the issue by accident as the door was a slider that parted in the middle and had 2 motorheads on it, one for each half, that drove them. I just happened to be servicing them and noticed that the spec plates on them had 2 different voltages listed, and questioned the maintenance staff about it, and they had no issue why. So I started looking into it, and that is what I found. Thankfully there were no accidents from the entire building being used as a neutral conductor, but it certainly could have ended up as an electrocution in the right situation.
Well that's a good thing that they used email and not something useful and immediate like a text message.
You definitely want to be sure your employees have to wade through dick enlargement spam in order to find out they shouldn't touch an entire building due to Mr. Electron running rampant through the walls.
clive has acquired a skill that lets him know if a product is designed to kill you or not just by looking at it !!!!
Clive !! your the next step of human evolution !!
Electrical engineering, tinkering with odd things.. you can learn that skill too. Just open everything you buy, there are patterns you learn. Any metal parts sticking outside from a plastic case that is connected to mains but not earthed = red flag.
"made in china" and bought from ebay is all you need to know XD
A made in china sticker 👍
It's quite simple really - 2 core power lead and bare metal components.
I'd earth thant anty enna.
@@millomweb If you earth that antenna, the bridge rectifier will explode as soon as you connect the power.
the positions labeled F and N are clearly oFf and oN
They probably thought "On and Off start with the same letter so let's be clever with our labeling"!
also f and n sounds like off and on.
@@AAAyyyGGG I think it's more likely that they assumed the capital O was just an unnecessary symbol.
@@gadgetman4494 Except "F" is off, at least on mine.
Foff and Non. Clearly a Google Translate error. LOL
At least it's transmitting in the 433MHz ISM band, I've had some Chinese RF remote devices that transmitted in the DAB radio band causing interference.
Is that not a kindness to your neighbours, stops them listening to poorly and over cheaply encoded trash. XD
I had an audio transmitter that did that but with phone service
That's what it *says* it's doing. Without a decent spectrum analyser, who knows...?
I bet its harmonics cover many other bands anyway
After watching you for a few years with general interest, I am actually beginning to not only follow the schematics, but understand the principles. Great video as always!
I bought a 4-button A/B/C/D version with the same F/N switch and telescoping antenna to control an LED swimming pool light. This was an Amazon purchase in the US. It claims a 1 km range and I thought it might be useful to control other things, but when I received it I noticed it didn't have any of the usual FCC markings. It's pretty easy to get a 1 km range if you don't worry about silly things like regulations. Judging by the amount of noise that comes out of my PC speakers when I press the remote buttons half way across the room, I suspect it may transmit more power than FCC 15.231 allows. I measured the frequency to be 433.92 MHz with a cheap Chinese SDR. For some reason one of the buttons had a slightly different frequency than the other three.
My receiver looks similar but it does not have an external antenna, so maybe there is no electric shock hazard.
Thanks for doing this, Clive. I did my own tear-down of the light but didn't think to open up the remote.
Look, a telescopic antenna. It's the eighties all over again. 😁😂
FIRST Cordless Phones...what a throwback
They are fun, can unscrew them and pretend it's a police baton
Wait... is that a cordless phone in your pocket or are you ready in case I fart ?
You should have a BC sticker that says something to the effect of "Identifying shock hazards since 2005"
Paranoid from childhood
EV1527 is a classic. Very hackable. It has 4 inputs, and every combination of the 4 inputs sends a different code. I've used it in projects to give a dozen or more buttons.
Wow
I shall watch this video to the end and things worthy of note, I shall wait patiently for the next video, Thanks Clive, love from Cornwall, UK.
Most of these RF switch/smart switch thingies don’t have enough room in them to maintain the double insulation into the box so I’d always advocate putting them into an enclosure anyway. However, the SMA antenna implies that the antenna could be remoted so it’s a fail from me ;-) Excellent teardown as usual Clive, keep up the great work!
every time I see you grab that thin red and yellow screwdriver I feel a wee bit more comfy and I cannot explain why
Because its a certified 1000V insulated electrician tool.
As you mentioned, these are often used to control pumps. It's not uncommon for a pump to be below ground and you wish to control it remotely from above ground. I think they set up the antenna this way so that you could have the relay in a box or chamber below ground, removing that little antenna nub and instead screw on a long cable attached to an external antenna above ground. Still, it wouldn't have taken much to add a removable cap or boot so that the metal isn't normally exposed.
In the US, 433mhz is a licensed amateur radio band, and you do occasionally get some naughty devices from China that use 433mhz instead of an unclicensed band (e.g. 315mhz). They’re not illegal, because they’re so low power, they just don’t work at all if you have an amateur radio operator using the frequency.
I think, that the 433 MHz band also is used in Germany for amateur radio.
In the UK 433Mhz is the unlicensed band and sometimes the Chinese send 315Mhz so this is clearly just a mistake
They also don't work when you have many devices in operation in the nearby area.
My grandfather eventually ended up in a posh "community living center" for the elderly. He was always an electronics geek and had to take his latest "weather station" with him wherever he went. The temperature/humidity probe was wireless and operated at 433mhz.
When he was still in his own home, the sensor had always operated properly, and he never had an issue with the display receiving the signal from it.
When he moved into the community living center, he had all kinds of issues with the display losing the signal from the wireless sensor. When he questioned me about the issue he was having, he had the sensor just sitting on the brickwork of the building right outside his window. I decided to help him out, and mount the sensor in it's proper bracket, which stands it off of it's surroundings, thinking this will help with his issue, but about halfway through drilling the holes in the brick to mount it I realized that this probably wasn't the issue when I spotted similar sensors mounted outside of just about EVERY OTHER window on the building. Yep, old people must just like to have their weather stations. His unit did have switches inside to change the channel for the communication between the sensor and the display. I changed his channel to a random combination of switches, and he had no more problems with it.
F and N are sensible for oFF and oN. Better to use the last letter of the words than the first - the labels 'O' and 'O' wouldn't be much help.
You know what's more sensible for two tiny words like off and on? 'Off' and 'on'.
They could have done the standardized O and | nomenclature...
The remote looks like it controls the trap door in an 80s villain's foyer.
A remote with a 9v block, that's a first, suppose it lasts for ages.
@@pear7777 "A remote with a 9v block, that's a first" uhm... what about rc cars?
@@chrisakaschulbus4903 fcuk, I'm getting denented, did I write that? I looks like it. Nvm, the rc cars run way more communications than an on off..
@@pear7777 everyone can have a little brain fart... it happens to the best of us as well...
sometimes when i cook and need to make my sauce tasty, i add honey and mustard and it kicks ass
The tri-state inputs on the back of the remote is so that you can give the remotes different addresses so if you had a lot of them you could make sure they don't overlap.
With the On and Off, clearly, the O is redundant. In Canada, where we have both English and French as official languages, the water taps are either labeled H and C or C and F. I’ve often thought it would make sense for them to be H and F (as opposed to C and C), so each language group would get one “good” letter, and the other as “not the good” letter, or something else bacronymed into the situation (Hot and Frigid as an English example)
The antenna circuit is decidedly odd: It has a loading coil in series (which is redundant if it uses a loaded antenna). And that means that the coax connector is no longer 50 Ohms, so the metal outer is completely redundant and doesn't need to be connected to "Earth" (eg it should have just been left floating). It rather looks to me that the design started life as a 27MHz remote and was clumsily redesigned.
Assume the F and N labels are for ofF and oN. English is a right-to-left language, right?
Well you can mark it O/O but that wouldn't be really helpful, right?
@@SonofTheMorningStar666 how about I/O, what do you think?
@@jkobain Nah. No one would understand that.
@@jkobain ⏽& ⭘ could work, or just ⏻ and let people figure it out.
Stop criticising. They very helpfully marked the LED with "LED."
These transmitters with otp codes are pretty nifty. I was surprised recently when I got two identical LED floor lamps, and their remotes didn't operate each other, they had those unique codes. Fortunately with a hacked Sonoff RF bridge I was able to read and reproduce the signals for automation.
Ironically, the external antenna might even make the reception worse. Those little boards are typically tuned at manufacture, so tacking extra conductor on the end without re-trimming might impact the receiver circuit (assuming this module even has the usual trim inductor).
I can also see someone deciding that the reception isn't good enough inside their plastic enclosure, so they install a bulkhead SMA pigtail, bringing that diode-to-mains shell out of an ungrounded case.
Yes, found the same with quinetic wireless switches here. They operate at an unknown band, but the antenna is a precise length of wire.... adding wire to it or removing any DRAMATICALLY detunes it
It still has the standard coil antenna which will interact with the exterior antenna. So the external antenna is a gimmick.
@@Electronics-Rocks its so you can tell its a reallllly good receiver!
@@km5405 lol
Yes, one would need to use shielded coax, and an external antenna of the correct length, for it to work properly.
Anyone else here clicking that like button on any video posted to Clive's channel even before the advertisement finished playing?
You get ads? I use an adblocker - works great!
And I have subscribed to TH-cam premium for 15£ and don’t see those infernal things 😁
It's a given.
@@Spiderelectron an adblocker is nice on PC but as soon as you watch in the phone app it's ads all over again.
Well unless you block ads by blocking them with your DNS server, like do.
@@nilswegner2881 Or install TH-cam Vanced.
F and N is from a bigger "OFF and ON" switch that has been hacked down to size!
Im not certain why it even needs that stubby antenna, other than to make it look cool. Ive used many of this type of unit, and usually that short spiral wire antenna gets TONS of distance.
I have another version of the same remote with 4 buttons for controlling a pool light and changing its color. It doesn't have the external antenna. Still 433 MHz. There is no need for that big 80s-cordless-phone antenna.
The crazy thing is, just yesterday I ordered a 12v remove relay with exactly the same control. The unit I have has one of those little pin connectors so you can move it for different modes. 1 mode is A- on and B- Off. 2nd mode is A- On A- Off B-Nothing. And if you take it out all together its just A-On until released. I am using its bits along with another external relay to make a buzzer to say when power goes off.
Thank you for that info. I've been trying to figure out how that damned jumper worked!!! The Chinglish in the product description on Amazon was no help at all.
@@mattelder1971 you had instructions? :O. I just did trial and error.
I added a DIY antenna extension to a plug-in doorbell from Amazon (UK) and when testing it, never considered for a moment that it would be at mains voltage. Well, a clean pair of underwear later and I was now a LOT more respectful of my dodgy antenna!!
I always power my antennas with full mains voltage for maximum wireless reception. Also prevents people from touching it... At least twice anyways.
When I saw the thumbnail, I got the impression the device had melted the plastic bulb. I was a bit disappointed when I learned that wasn't the case.
But when I heard the word China, my joy returned.
Why didn't they at least separate the RF ground through a 1pf capacitor?
That capacitor being removed saves a penny!
That's how it was done on hot chassis TV sets.
Indeed it was, though the capacitor values were usually a lot higher than 1pF. At least for the older sets that needed Band 1 reception (40 - 70 MHz) the capacitors would typically be 1nF, (or .001 microfarad as it would have been described at the time). These capacitors were also usually shunted by a resistor, typically 2M2, to discharge them.
@@eDoc2020 And many tube radios back in the day. Though they sometimes didn't bother with the capacitor for those too, leaving the chassis connected straight to the line (unpolarized plugs back then, so 50/50 chance to have a live chassis). Even when there was a cap, they almost invariably short over time. Fun stuff.
I bought a $7 SONOFF a few years ago, and really like their design. Upgraded the firmware to run Tasmota. Love it.
This is nothing but an old garage door opener chip and easy to hack. Also, the 2W standby power is just ridiculous.
It's possible that the "F" and "N" on the transmitter switch are short for "off" and "on", but since they start with the same letter, they just used the second letter of each word.
OG [I/O] doesn't do it anymore?
@@jkobain I always thought I/O was odd. If "I" means current then what is "O"? If I is a pictogram of a bridged circuit, then O is.... huh a loop? Is I a pictogram and O just stand for "off"? One way or another its a broken abbreviation or metaphor.
@@carpdog42 I=1 O=0. 1 is on, 0 is off
@@boulder795 I'm amazed at the number of people I encounter that don't understand this. I guess growing up in the age of the 8-bit microcomputers and learning about binary very early on, it just makes sense to me, where people who have never really dealt with binary are totally confused by it.
Clive, I must admit these video’s are getting juicer each day. 👍
Yay for saying PP3! I was starting to think I was the only person that didn't call it a "9V battery" these days.
Even better is a PP9 😁
If it was meant to be enclosed in a box then why is the antenna exposed? Seems like what you really have there is a wireless taser :-)
I believe so that you can run an antenna cable. For example, imagine this relay is in a chamber deep below ground and you want to control it remotely from above ground. You could then run a conduit for an antenna so you'd be able to receive a signal from above. Still, they could easily have made a removable cover or boot as a safety precaution.
@@NorthernKitty Which sounds like a great way to cause radio interference thanks to its unique "feature".
I'd like to see how the design would be fixed
_“This chip isn’t powered until you press the button. Very strange…”_
I don’t really know about this stuff, but isn’t that why/how it draws no current while idle? 🤓🤔🤷♂️
It's the way they did it that was odd. But subsequently turns out to be a datasheet example.
@@bigclivedotcom Maybe that controller doesn't have sleep or low power mode... which is still odd for a mostly battery-operated ASIC... but they solved it with this workaround. It's much more difficult to do this hack on silicone level :)
On newer MCU's this hardware wake up circuitry is built in. Just tickle a pin and it will wake up and do a thing and the go back to sleep.
@@janosnagyj.9540 Impossible, I'd imagine, to hack it with silicone... :P
I'm torn between strange and an old-school brilliant way to save that poor old 9v battery as there is no "idle" state. Other then the slight "parasitic drain" this thing draws next to nothing when the buttons are open. Just enough to cause the battery to leak out in a few years of being lost behind the couch. Reminds me of my first TV clicker, back in 1970's-something. Way to go China, always pushing the curve in engineering advancement
Hey I've been watching your videos for a very long time now and I noticed I've never subscribed wonder how I missed that. Anyway now am in thanks for the very informative content I love them keep them coming.
@21:00 in the video. The use of the PNP transistor in that circuit is not strange. It's quit ingenious actually. What they are doing is making sure that no parasitic/stand-by current is being drawn by the uC, ensuring that the circuit is 100% off when not in use.
Neat, besides the way it gets it's 24Vdc.
Touching the antenna connector will brighten your day unexpectedly.
I just got a similar unit from Amazon through the Vine programme. The antenna shield on this one is wired directly to neutral, so it's getting a nice PAT fail photo for the one star review.
So how do you decouple the exterior casing of the antenna from the mains supply in a design like this?
a low value capacitor in series with both legs on the board to be safe. something like a 100pf or less would be a short at 433mhz but not let through any AC mains.
Mount one of those locking thermostat boxes over it.
throw it in the recycling and buy a safe one.
That remote looks so 1980s. Reminds me of the toy walkie talkies I had as a kid.
"A" and "B". Activate and (then) Burial.
They could put two capacitors in series to the antenna connections. Those would let RF through, but they would block mains frequency.
I was thinking the same but maybe a better solution is to use a small RF transformer. I've seen some of those in the past. They are small and I think in general there is less risk to dielectric brakedown with respect to caps...
It's a shame because the circuit seems to be well designed (better than the eBay Chinese electronics average)
Blocking capacitors on the mains to exposed parts used to be a thing. They got nicknamed "death capacitors". Any exposed parts has to be fully insulated. Electronic parts can short, and things get wired up wrong. Nothing should ever be "made safe" by trying to Isolate it with an electronic component in series with the mains.
@@killcar5nbike2 This should be the kind of capacitors, which are used in switching power supplies between primary and secondary side.
@@JendaLinda they are earth connected surpression, not connected to the line.
No device with any external conductive components or user made connections can be referenced to the incoming line.
@@killcar5nbike2 Look at any USB charger. There's no earth connection. The primary is referenced to mains and it is connected via a small capacitor to the secondary.
"Nice big chunky terminals. That's a good sign." - I feel like the live exposed metal is a much bigger bad sign.
Chinese engineering has met our expectations this time. Great device
Me: picks things up by the antenna.
Also me: checks live wires with fingers.
Also me: has abnormally high skin resistance.
Looks like fun.
I somehow want to buy this more.
Don't really on your high skin resistance to much. Water makes a huge difference.
@@bigclivedotcom
Good thing I'm always dehydrated...
.
Jokes aside; I do take due precautions, only messing with known values.
Although as a kid, how I learned of my resistance... I was the kid who put a finger in the light socket, and switch contacts, and plugs... Probably why I got interested in electricity and electronics.
Cover the exposed antenna with a thick plastic housing. Then it would pass. So near to a great design. Zapp! Brilliant video. Thanks.
5:10 may not necessarily be mislabeled. If you check continuity between live and neutral, and you still have a load connected such as a light bulb, it will still ring as continuity.
good point !
10:45 proves him right, though.
👍❤Thanks Clive for your great videos.. a well spent time indeed!!
You could easily put some heatshrink over the exposed metal of the antenna.
TH-cam says you've commented 2 minutes ago. I came to the comments 10 minutes ago to find this comment.
Perfect, even with live and neutral swapped for maximum shockage :D
The two amplifiers in the remote are probably also there to reduce harmonics when transmitting.
Have you considered using a rtl-sdr dongle to get RF samples? It would be some a trivial to sample and display the bit pattern code.
Since this transmitter uses on off AM style you'll be able to see the pattern just by looking at the waveform.
I would suggest using the rtl_433 program, it has a feature to use display the raw and demodulated waveform with timing.
Other than the live antenna I'd say this was decently designed, very nice pcb!
The way the transmitter switches power the IC via the transistor keeps the quiescent current super low. It is for long battery life.
ofF and oN maybe?
Better than Off and On I suppose
@@wich1 simple 1 and 0 would have sufficed.
I remember when I was an avionics technician in the Navy they told us that even 100mA can be fatal in the right conditions, so 75mA is going to give you a decent shock.
If the zener voltage has a positive temperature coefficient they will tend to balance out. The one with initially lower voltage will conduct more and warm up more, thus reducing the voltage imbalance. It will not balance perfectly, though.
Cut the ground and signal lines to the antenna and put 220pF Y type caps in both paths. It will still work and it will not be a shock hazard anymore. It was a method Phillips use to use in their TVs.
Capacitor Dropper is used because it is simpler and cheaper but a potential hazard.
Some models from other companies have switching type power supply.
With unisolated buck regulators in some.
738K subscribers, congratulations 🇨🇦
The "N and F" positions, my guess has to be they just took the last letters of On and Off and stuck them in the side. maybe they don't know I/O yet?
Programming modes for these remote switches are often momentary (single button), continuous (while single button pressed), toggle (single button) and on/off (two buttons).
I can't see that momentary would be much use in a switched relay configuration though.
That "little antenna" is a simple RF low pass filter. It not part of the receiving antenna due to too being connected at both ends, and the ground plane surrounds the antenna connection, helping to separate it from the main antenna. Because its unshielded, it can serve as a very weak antenna when the main antenna is disconnected. It can also serve as a loading coil for the antenna due to the antenna is way too short for 400MHz use. Its been years sense I did antenna/RF theory work, so some fine points I may be wrong on.
Another great Video from Clive👍
I wonder how many of these eBay or wish things are factory rejects. Like they made up a batch with the wrong stickers and decided that it was better to just sell them cheap than put on a new sticker or dump them.
I've seen it with like chef knives. It's pretty smart.
The two 24V Z diodes are no problem. Above 5V the TC (temperature coefficient) is positive. For 24V the tc is strongly positive, probably around 15mV per K so if one gets hot, the current goes to the other.
With a thermal camera, one was much hotter than the other.
The 2 Zeners are not in parallel to share the load, one is just a hot standby if the other one blows.
Except that semiconductors fail by shorting. Besides, nothing else in this thing in redundant, why just the zeners? They clearly are sharing the load and two 12v zeners in series would be a better idea.
Not bad! Very nice design inside the remote, ensuring that nothing trickles the battery down with its quiescent current. At this point I'd guess the function of the switch is more to prevent accidental button presses rather than help with battery life. As for the antenna (which, as someone has already pointed out, appears to be incorrectly wired to an existing internal antenna), an easy fix would probably be to swap the diode bridge for a half-bridge rectifier. This would ensure the antenna is always referenced to Neutral, which although not ideal, at least won't shock you under normal circumstances.
Capacitive droppers don't work with just a single diode half wave rectification.
@@simontay4851 You're right, my bad... A couple of back-to-back 24V zeners strategically placed after the 68 ohm resistor would help, but that'd probably dissipate too much power.
Edit: or rather a zener in series with a regular diode.
You also have to allow for miswiring or unpolarized plugs.
@@bigclivedotcom Yeah, as I said, not really a proper solution... Still better than guaranteed 300V pk-pk on the exposed part. On the other hand, in case of miswiring you'll get full 600!
This piece of equipment could be quite the shocker, eh? Truly a Beast from the East
to add a few items (which Clive mentions the pick up coil), the RF section: on the receiver side, there appears to be a small "pickup coil" which will allow the thing to be operated without the external antenna connected.. it may have been an after thought to add the external antenna; they COULD have isolated the external shield on the RF connector with a pair of 20 pF ceramic caps to the common of the circuitry and this would have isolated the mains from the exposed metal parts of the antenna circuit.. On the transmitter side: this appears to be a "saw resonator" type RF circuit.. quite similar to a "garage door remote control" though slightly-modified with a buffer amp and external antenna.. the rest is as expected. Overall, from the RF side of things, this is a POOR quality RF link.. I would think this has a effective range of maybe 1000 feet outdoors, 'line of sight' (much less range indoors).
@3:46 Wait until it’s dark. Put the light in the window?
I can (sort of) see the logic in the parallel zeners. If one goes open, you still have one to hold the rail to 24V, otherwise, the voltage might go very high. This would not be the case with series-connected zeners.
Looks more like two different resonance coils for the two options of freqs .. on the remote anyway
Lovely! I love it when we have parts that are easily touchable, that are live at full mains voltage :).
In fact, you could add an external antennae to it (which is more powerful/more directional). Would that not make the antennae live?
1a. if you do put the remote into service you will need to isolate the receiver unit such that no one can come in contact with the antenna either by enclosing the receiver module entirely in a plastic enclosure or placing the unit well out of reach of anyone and have plenty of warnings like antenna connector presents a shock hazard disconnect power before adjusting or replacing the antenna.
1b. in theory you could power it from a 24 volt power supply. bypass the dropper to run input directly to the output of the rectifier diode block.
then power it from a 24 volt doorbell or hvac transformer.
you can get doorbell transformers from your local builder's shop or ebay.
hvac control transformer you can get from your local heating and cooling or even plumber shop.
if you are lucky and can get access to a house that is marked for demolition you can go through and salvage some of the stuff.
2. the remote uses the ask ook banding.
3. the interference that your hand presents to the antenna of the transmitter is exactly how a theremin works a theremin exploits that interference to control the tone.
Let me clarify some of those abbreviations
On the remote F/N is Functional not active / Now functionally active
On the output terminals A is Another neutral and N is Not neutral
Also ANT is not short for Antenna it is the Auxiliary Neutral Terminal
No sure how you could find that confusing.
F and N are the last letters of on and off, words that both begin with the same letter O
i like that, its nice and sturdy but with just the right amount of danger
You know what video I'd really like to see... something demonstrating the issues with these mains referenced exposed metals... something maybe starting with an oscilloscope and ending with some bangs and flashes and maybe a hotdog or two for human finger substitutes ;)
The only reason I can think of for the PNP switch arrangement in the remote is so the input is not pulled above Vcc. With this arrangement the inputs are a diode drop below Vcc (minus Vcesat which shouldn't exceed ~100mV). Using a diode to power the chip puts the inputs above Vcc by one diode drop. A lot of chips gets very upset (and even fail) when an input is driven above Vcc.
Their thinking must be that referencing to neutral is kinda ok for industrial wired in stuff. Not good for portable or residential where getting the hot and neutral swapped is much more likely. Just cutting the ground side of the RF connector and inserting a .01 cap would allow the rf to flow and the AC to not. Seems like a simple mod if you wanted to use one of these to say, control a dust collector in a shop for instance.
Enclosed Mean Well PSUs have mains terminals like that. The annoying thing is that 99% of the time when you get a used one the terminal cover is missing and Mean Well doesn't seem to sell replacements.
17:50 The two transistors aren't a "buffer" its to get a resonably high power output, ima guess from the transistor size proabably 500mW
Deep, really deep. Love it.
It is strange that they didn't just put a small capacitor in series with the antenna connection. That would limit mains frequency current if you touch it to a very low value while letting the RF through. When TVs had circuitry running directly off the mains the aerial inputs had just such capacitors.
That 680v MoV is interesting. If you are about to design capacitive drop power supply look up „ tdk everything for capacitive dropper”, very usefull stuff, also „cap drop offline supply texas instruments” or „AN954 transformerless power supply”
I've heard of an "active" antenna, but this is taking the biscuit! Live transmission coming soon? ☺
Clive said "Here we go" and then "There we go". I was running back and forth. But he did get that remote open quite smoothly. ;-)
You know, what they could have done is put a y class capacitor in series with that antenna. A couple hundred picofarads should do. Low-frequency AC is mostly stopped by that but RF goes right through it. Additional cost is very low but it's much safer.
Love your videos big Clive. I wish I had your understanding of electronics. Jealous
I don't think made in China necessarily means bad, but it does mean less regulation, so quality can vary drastically
that little daniu transistor tester you have can show you the code from remotes like that and tv remotes etc. i wreaked mine by connecting it to a charged capacitor by mistake. Anyway! nice video.
Put some shrink sleeve on the exposed metal antenna part... sorted. :)
Yet another live item from China lol I bought a set of mains powered lights from China just before Christmas and got a zing off it, 1 diode between you and certain death 😁love your vids mate stay safe and sound in these very uncertain times
23:12... You could remove the PCB antenna connector and solder a similar length of antenna wire as the Transmitter uses to isolate the live Neutral by keeping it inside the box.
To be fair, provided the Live and Neutral have been connected correctly the voltage on the antenna is only -24V so if you get a zap from it then it's your fault for wiring it wrongly.
I found a delightful little DIN rail "panel" relay from china.
It "claims" 63A, but I somehow doubt that. It would probably explode if it tried to switch 50A, especially with any kind of inductive load.
It does make a rather chunky relay noise when it turns on and off, at least.