Inside a "4kW" ebay power controller with schematic.

This is a look at another Chinese industrial control component.
You can support this channel at / bigclive
At first glance this phase angle power controller has a strong case resemblance to the common 12V chassis power supplies. But this is a beefy triac based mains power controller for things like lamps, heaters or some motors.
It has a few notable features:-
Nice case, beefy triac (one of the biggest of its type if it's original), extra circuitry to give greater stability and output symmetry at lower levels and a bit of effort to ensure that tracks are robust enough to handle fault conditions.
It does have two slight issues. A glass fuse instead of a ceramic one and a seemingly excessive resistor value in the snubber network. 4700 ohms as opposed tot he more common 100 or even 47 ohms.

[@chuuni6924]

I've always wondered why those diac/triac dimmers can't dim evenly down to complete shut-off. Thanks a ton for explaining that!

[@HennerZeller]

I have myself sometimes used bridge rectifiers different from their 'normal' use because I needed such a particular diode arrangement and they happened to come in a cheap package like that. Of course the meaning is disguised just seeing this as rectifier symbol in a circuit. It always makes sense to actually write out the diodes in a schematic to see these kind of hidden (rather interesting in this case) meanings. Thanks for the teardown and detailed explanations about your findings.

[@youtuuba]

For what it is worth, a company I used to work for made a whole series of TRIAC based DC motor controllers, and the snubbers were all 47k and 0.01uF (10nF). I never questioned how they got those values, but the circuit and TRIAC worked fine.

[@NicoIsntHere]

I have no background in electrical work and struggle to wrap my head around watts vs amps vs volts (basically anything electrical) but I still binge watch these lol. Great presentation and ability to talk fluidly!

[@macey75]

Fluidly? Do you mean "Fluently"?

[@NicoIsntHere]

Gregg Macey nope, fluidly. Like water, he is able to ramble smoothly. Fluidly accurately describes that.

[@RaynaDJ]

Gregg Macey lol

[@icarossavvides2641]

It's ELECTRONICS not ELECTRICAL!

[@cliffordwagner]

It might be informative to see that power supply connected to an oscilloscope comparing the waveform while using the 4k7 in the snubber to that of a 100 ohm resistor. I wonder how it changes the snubber performance.

[@skepticalexicon3534]

would it be worth swapping it out anyway?

[@alchemy1]

Yea that is what I was wondering about. But I trust this schematic compare to what is being pushed out there as 100 ohm. Also the extra resistor that goes with the potentiometer is in the middle between it and the capacitor. They are typically shows to be above the potentiometer. I wonder if that matters or not. Probably not. But the whole idea of the bridge rectifier, I think it is a big deal and what has been explained makes lots of sense. Stability matter big time. I know that without it, any good motor will act as if there is no potentiometer and by pass it and will take off without doing anything.

[@crazyirishman121]

The great Resistance on the snubber is effecting the time constant of that of the RC configuration (Making the charge time longer). This most probably reduces stress on the capacitor when there is a high inductive load present .

[@bogywankenobi3959]

I had to watch the bridge rectifier explanation twice before I got it. (I'm getting old.) But that is quite genius. Thanks for the explanation.

[@bigclivedotcom]

It took me a while to get my head round it too when I first found it.

[@Roy_Tellason]

@@bigclivedotcom Can you give a link to that application note?

[@simontay4851]

I bought one of these after watching Clive's video. I added an earth wire to the screw and added a large inductor to the output. Also insulated the top and back of the heatsink because it is VERY close to the case.

[@MrSte2222]

I did exactly the same as you as i was concerned about proximity of the heatsink to case screws and added an earth

[@joradcliffe565]

Assume an inductor on output would be unwise if load was also inductive such as a motor ?

[@simontay4851]

The inductor is to filter the output. This device works the same way as a light dimmer. If you take apart a dimmer switch, it has a coil and a small X capacitor (100n) on the output.

[@simontay4851]

i tested vacuum cleaner universal motors before with this and there were no problems. It handled the inductive load fine.

[@simontay4851]

I also use it to slowly increase the input voltage to SMPS that ive repaired. I can't afford a proper variac.

[@hightensionlabs]

Thank you for mentioning Amateur Radio it’s much appreciated.

[@gmtech68]

Agreed. VA6MEC

[@Roy_Tellason]

@@gmtech68 Yup! WD3WTF

[@extraglutenplz3758]

Hey Clive I know you've done a computer power supply tear down but I was wondering if you could compare a cheap PSU to a notable good quality one....in terms of quality of components and circuit architecture.

[@sykoteddy]

That sounds interesting and I am also in favour of that test. But I know that the brand Seasonic pretty much is the leading producer and that they make most of them. Just look at their warranty of 12 years!

[@Scootertuner420]

@@sykoteddy Computerparts doesn't have to be crappy, as the requirements rising with every new release of hardware, I still have some 20y old hardware that runs well, even the cheap stuff. Some cheap psus blow up because people tent to run them close to theyr limit. Back than a 250w psu was enough, my 4y old setup runs on 550w psu, the one I build 2y ago already need a 660w psu and a pc with very recent hardware requires at least a 750w. Just as an example, that hardware just ages quick enough.

[@milankylan7037]

instablaster...

[@eletrotheory8398]

@@Scootertuner420 Well , in case of PSU's those are probably one of the components that you can not buy a cheap one, nor a expensive, just the wattage you need from a good brand, because very cheap PSU, uses components such as capacitors that are far from what we call a pure component (important for signal conditioning and noise filtering), and what's the problem? Unwanted current spikes, instable voltage, your coomputer will work however motherboard components will suffer, motherboard needs to work with a good PSU so the signal flow will be "smoother" I mean the risk of getting a wrong reading or a exploded cap on mother is lower; Also let's say that you house main fail the chance of a cheap power supply produce a giant current spike and your motherBoard get fried is even higher, I am the guy who bought a cheapier GPU to get a powerfull PSU and guess what nowadays I have a beast gpu with the same PSU chillin cause I know that whatever it happens my PSU will handle the situation while with a cheap your brain will be Please do not burn anything, It is like driving a car with bad tires sooner or later something will happen....

[@andyxox4168]

@@Scootertuner420 only 20 years … I still have a UK 101 that I assembled myself in 1980 and that runs fine .. 😂😂😂

[@Landrew0]

Congratulations on finally solving the white-balance problem. Good job.

[@TrevorJoynson]

Man your videos are great, I think I just powerwatched ten of them. Keep it coming :)

[@jackiebutler5025]

I use one to control the heating element on my pot still, it works a treat and the controller only reaches 40-45C after 3 hours use @2600W load which I think is acceptable and definitely better than I expected when I was installing a cheap Chinese component.

[@RODALCO2007]

Great video, interesting application with that bridge rectifier.

[@Andromedan]

As a radio ham, I don't actually use those bands (2m/70cm personally, I know some HF guys though), but the only thing worse than an unfiltered dimmer is those awful powerline ethernet gadgets. Great way to turn all the house wiring into a giant antenna for digital noise! 73s, 2E0GXE

[@drkastenbrot]

Powerline units are a ridiculous waste of power too. I had a set which took 16 watts. All day long.

[@simplexicated]

+drkastenbrot Very interesting you mentioned this, I decided to check the pair I own. They do seem to be getting a little more efficient now. It costs me £2.09 pm to run mine with no idle at all. They run at 5.6w on full load. Further reading for those interested here: tinyurl.com/nbb9hmc

[@TheChipmunk2008]

+drkastenbrot Yeah, I have a system that can get ethernet from one end of the house to the other with no power usage above normal at all! (it's called a cable lol)

[@Firecul]

+TheChipmunk2008 I wish I had ethernet handy when we had the floor boards up to fit the central heating, I would have loved to wire up the house properly. I have to make do with powerline, not the favourite solution but the best for the circumstances.

[@JonaJona]

+Ben Thomson Usually even WLAN is more performant than that and it at least stays on its frequency. Those thingies are really just made for the "oh my god WLAN is killing me" guys to make money. In the end you'll have more fun putting a proper cable in your house or moving the computer. An idea I just had is just putting a directed antenna(like 20dB) on your WLAN. That wouldn't emit any electromagentic waves where it shouldn't and gives a solid connection as long as no one walks through. 73 DO1JOM

[@neilphilip2320]

Superb! Like a previous comment I wondered about the poor performance of dimmers at low levels and now I understand why!

[@krampdrucker1753]

I've been wondering about this topic for three weeks. Thank you!

[@TheHaerlings]

The label is very logic, it's a very efficient way of supplying the sticker for your case, you peel of the blue part, then you peel off the sticker from the blue foil and stick it to your case where the module is installed. By doing it this way they are 100 percent sure that the sticker doesn't get damaged during transport.

[@svenonderbeke]

Thanks for this explanation, I've draw the schematic of the controller myself and was wondering what the purpose was of the bridge rectifier, you made it clear for me!

[@Mekchanoid]

I can't admit to understanding all the electronics, but was delighted to hear that this regulator is designed to deliver smoother power at the lower end. My Ryobi drill is very spluttery and rough on slow RPMs and I'm really hoping this will help that. Also, several units of this type have been condemned as death traps, with circuit boards virtually touching unearthed casing, so I'm glad this thing appears to be relatively safe (despite looking hideous and having only one mounting hole on the front). Thanks for the clear and meticulous breakdown.

[@bigclivedotcom]

None of these modules are really up to most safety standards. For better drill control I recommend a good cordless drill.

[@Mekchanoid]

@@bigclivedotcom Thanks. I'm using my corded drill in a stand. Unfortunately most cordless drills have a pressure-controlled speed trigger which can't be accurately dialled in.

[@AlexKiraly]

Your videos are so relaxing. Anyone with a bit of knowledge about schematics and components in general should be able to understand

[@danceswithaardvarks3284]

Thanks Clive. I was just investigating putting a treadmill motor in my mini lathe and you popped up in the recommended. Bonus, because I hadn't seen this video.

[@lumpyfishgravy]

Another point to note about fault conditions is the extra solder they have put on some tracks. In fault conditions this will sputter or could even create a vapour cloud which shorts out *everything*. Fault condition testing can be quite fun actually! Place a sheet of blank paper under the board to catch the sputter, then hang it on your wall!

[@TangoMike88]

Why am I even watching this? I love you Clive!

[@Shaun.Stephens]

I see that the youtube algorithm has chosen this video for this week. I watched it a few years back but that was on my other account so decided to watch it again. I'm pleased to say that, having watched Clive's videos for a several years meant I understood this so much better this time around. :) Learning by osmosis is so much easier than studying.

[@bigclivedotcom]

This video seems to be very active at the moment. I'm not sure why.

[@Shaun.Stephens]

@@bigclivedotcom I've noticed it being suggested to me by youtube all week. It seems that you've won the youtube lottery! ;)

[@Shaun.Stephens]

Wow! Even though I watched this yesterday it's STILL in my feed! I had to click the three little dots and tell our overlords that I'm not interested in watching it yet again.

[@foogod4237]

This is why if I'm drawing out a circuit with a bridge rectifier, and it's not immediately obvious how it's being used, I do _not_ draw it as just a "box" like you did. I draw out the full "diode diamond" instead, because that often makes it much easier to see what's going on if people are using a bridge rectifier in an unconventional way (i.e. not actually as a rectifier), which does happen surprisingly often I've found.

[@jlucasound]

The one thing better than watching you "take things to bits", is you explaining what is going on and whether the bits are good or not. You know so much shit about electronic circuits. You are so good, Clive. And Your Delivery!! Ace, Bloke. ( I am US. I hope "Bloke" is not an insult. I know; "Google it!". I don't think it is an insult. I am rapt when watching and listening to you. Thank You, Clive.

[@JerryEricsson]

Wow glad I found this video, I have one of these laying in a box back in my garage in South Dakota (I am hiding from the winter right now sitting in the Sun in Arizona at this time) It has been laying there now for a couple of years because I really didn't dare hook it up to my wood router. That what I purchased it for, as my 2.5 horse router is a single speed, and I have some huge bits that cannot run at full speed, lest they shake the whole machine apart. These are made for cutting things like chair rails or making cabnit door inserts. If this works right, I can slow the machine down enough to make the cuts without burning up the bits or tearing up the wood when it begins cutting. MIne came with no labels on the terminals but I have taken it apart and pretty much figured out which is which, then made a label for it so I would remember it the next time I dig it out. Thanks a million for explaining how this works and how to wire it up

[@JerryEricsson]

Well here it is, another year has passed, the regulator is still laying in the box in the garage. The router has not been turned on, in fact my daughter knocked the hell out of my table trying to get an old bicycle out so I could try and sell it, and I have yet to build up the energy to go out and see how much damage has been done. She did it at my request so I can't really blame her. Doc's say I am drugged out on the prescription meds they have been telling me to take every damn day so now the weaning off of narcotic and anti what ever the hell they are anti drugs. My head seems to be clearing, after 3 months of sleeping day and night with only waking hours dedicated to eating and going to the BR. Nice to be awake again, but most of the damn spring and summer have gone and I have done NOTHING. Damn doctors anyhow.

[@inseries5494]

@@JerryEricsson Get well Jerry!

[@TheBrick2]

Thanks. I learnt something and that's the point. Never knew about the ceramic fuse point either. Really useful one to keep in mind. I often wondered about the sharp edge from triacs on inductive loads especially transformers. I was thinking or experimenting wit ha large triac before a arc welder to drop the power but was worried about the high frequencies generated causing massive heat problems in the welders transformer.

[@crocellian2972]

The Chinese have several "standards" like the EU DIN packages. In many cases, the frames are the protective earths. Cheap, fast, safe.

[@rogerwilco2]

Radioastronomers hate RF noise as well.

[@alexandercollignon4819]

So I find a thing I really would like to find out more about and Clive already did it specially for me 5 years ago it seems 😂 thanks Clive!

[@Jademyheart]

Good informative upload, there Clive , cheers 👍

[@JerryEricsson]

I have one of those. Never have developed the guts to hook it up since it came with no documentation, and no markings as to what hooked to what. I did take the cover off, and sort of figured out how to hook it up, the plan was to control my router for my woodshop so I could cut down the speed when needed. That said, it was advertised as 240/110 volt and I was really hoping it would work but after having problems with about every item I got from China that had the duel markings I decided to let it sit in a box out in my garage. Thanks for the info, when the snow is at last gone and the weather warms a bit, I may try hooking her up to my router table and see if it will do the job for me.

[@GeorgeGeorge-xj2bc]

The snubber circuit in parallel with triac anodes always allows a leakage current.With these values is about to 6mA.Larger capacitors and lower resistors allows high leakage current.Especially when triac is used as an on/off switch then you might notice your low consumption led lamps to flicker when supposed to be switched off due to that leakage current.

[@KarldorisLambley]

i instantly knew the 470k R should have been 100, as i watched your other triac vid 20 mins ago, the 2 together are amazing. i especially like the journey of FBR discovery you personally embarked on in this one. and saying a diac is a bit like a bi-directional zenner made it's effect instantly comprehendible. thanks

[@LukaLatinovic]

I have disassembled several of those controllers, because it's way cheaper to rip them apart for components than to by components and in every one of them it was 100 ohm resistor in snubber circuit, so I am with you. I think that you are right when you say that they have made a mistake.

[@MrMurphyprecht]

"I'll put that away cause it's quite shite" Mate, as a fellow Scot, that made me chuckle

[@nozynoz]

Excellent, thank you for the video.

[@Roy_Tellason]

Back in the first half of the 1970s I took a standard electrical box and installed a dimmer in it along with a duplex outlet, the original use for it being to subdue the lights on the christmas tree at the time all incandescent. After that this device was used to dim the bedroom lamps, which worked out quite nicely. Unless I wanted to listen to something on AM radio, in which case I had to turn the unit off, or the generated noise made it impossible to use the radio. I have some salvaged ferrites and should probably install one in there, as I don't believe that it came with one installed. So many years later and the thing is still working fine, excepting a bit of mechanical sluggishness in the pot. More recently I offered to build one of these for my lady, and we went out and got what I thought was the same stuff, and I built it. Unfortunately that one displays the exact instability you describe here. Turn it all the way down so that the light pretty much goes out, and then when you want a bit of light you turn it up but nothing happens until you get to a certain point and then it *jumps* to more light than what I'd wanted, at which point you can turn it down a bit. The dimmers in both cases are the sort of thing that might be installed in the wall, as the last place I lived had one for the light over the dining table (which I had to replace when it decided one day to let the smoke out). I haven't really opened them up to see what the differences might be, or why one would exhibit that behavior and the other one didn't. Do you have any thoughts on this?

[@frollard]

Always something to learn!

[@phonotical]

Since you reviewed this, three years ago now, the only thing different between this and the ones sold today is seemingly the blue protective film, and the screw terminals are marked, and have by he same yellow/orange cover as the power supply

[@gnuthad]

I like your comments regarding ceramic fuses. It should be noted, however, that not all ceramic fuses actually have sand inside them. The fuses sold by a particular Australian and New Zealand electronics retailer (known for ripping off Freetronics work) are standard air-filled fuses but have a ceramic case. The inside is identical to your normal glass fuses although the fuses are sold as ceramic fuses.

[@bojackh5812]

Very interesting, never seen this bridge rectifying circuit before, genius though. Thank you

[@stevenking2980]

Excellent video sir.

[@alt-w7130]

Thanks for sharing this review, I like reviewing stuff before buying it. You said you have not seen it built like that, you never to old to learn, might be a 10yrs Asian boy or girl took a old made controller and improve on it to power and control a toy they have or school work where their teacher give them projects to improve on old equipment. Never underestimate the Chinese way of doing things.

[@hectorpascal]

In my experience electronics design engineers in China are generally first class at their job. Most problems arise from the changes made when management tell the production guys to cut costs below the limits needed by the original design.

[@muradalmuti]

I used it on a welding machine and changed the fuse with 20 amps and it works

[@ramraja7796]

20 Amp ! you might as well put a 3mm nail, It will work !!!!!

[@cheek1m0nkey]

My version that I just bought a couple of weeks ago came with a 20A fuse installed.

[@Centar1964]

This is for resistive loads only (Power factor 1) and is triggered from the load, for an inductive load (power factor other than 1) you need to trigger from the line and there are power controller designed as such. Also when triggering from the line you wouldn't need that extra circuitry to stabilize it. Basically this is just a high power light dimmer. BTW the 10 amp fuse will only give you 1200 watts at 120 volts and 2400 watts at 240 volts...

[@ziopoe]

I've dismantled a faulty dimmer that came with some fake Arri light a year ago, the inside schematic is quite similar and the fun facs is that the pcb has the room for the bridge rectifier but is not used, if you are interested i can send you some photos of that circuit. (the Ebay listing is no more available but it was called: As ARRI 300/650/1000W Tungsten Studio Video Spot light+case+Air stands Kit)

[@SouthwesternEagle]

Sometimes cheap Chinese generic products are truly good quality.

[@sup3rbird]

Usually, because they don't know where they can safely cut corners and still have it working.

[@runforitman]

That’s the thing with China; some stuff is really good quality But the overwhelming majority is junk So it gets the bad name It’s hard to know what’s good and bad when everything is a clone

[@filenotfound__3871]

Ha, geiiiiiiiiiiiiiiiiiiii

[@jeffwells641]

@33Ddg209Ret7 A huge percentage (majority?) of all super high quality tech is made in China (e.g. iPhones, etc), it's just that almost all the super low quality tech is also made in China, and there is a lot more of it.

[@JP-re3bc]

@33Ddg209Ret7 iPhone much?

[@runforitman]

This also taught me that the dimmer in my lamp must be one of said unstable dimmers; the lamp will suddenly come on after you’ve turned it a bit and will the have dimming function

[@alchemy1]

I must say this is the most useful and no bullshit video I have watched thus far. And I thank you for that. I am curious how you found that resource in regard to getting to explain what was going on. Also there seem to be just one capacitor in the diagram. There is two caps in the device. And I thank you once again.

[@rimooreg]

Thank you for the fine lesson.

[@brianregner5209]

Hey Clive, have you tested yours? Just bought one. Tested it out, and it works beautifully.

[@stephenhalliwell4720]

no plans to plug it in and test it out?

[@clems6989]

Excellent job

[@time17psn1]

I have no idea what his videos are about or understand what's going on but I can't stop watching

[@mauriceeley621]

DITTO

[@fulwoodphantom]

Clear as mud!

[@NavinBetamax]

@@fulwoodphantom.... but....it never covered the Ground ?! Lol.

[@friedmule5403]

I have a suspicion on that the 4K7 is also for stability, I think it is a part of making the rectifier stable at low voltage, but have you found it out?

[@TheFrenchMansControl]

Was kind of hoping you would test it and see how close to 4kw you would pull before it chooches

[@andysworkshopuk]

Clive's rule of thumb for about 1W/A power dissipation is about on the mark for this device. Here's a table of common UK heating element values versus amps and heat dissipation (plus 4kW). Values are Watts RMS / Amps @240V / Watts heat. See AN2703 for the equation used. 𝟸𝟶𝟶𝟶 𝟾.𝟹 𝟽.𝟶𝟽𝟷𝟼𝟾𝟻𝟶𝟷𝟽 𝟸𝟺𝟶𝟶 𝟷𝟶 𝟾.𝟼𝟻𝟸𝟼𝟾𝟾𝟼𝟾𝟽 𝟹𝟶𝟶𝟶 𝟷𝟸.𝟻 𝟷𝟷.𝟷𝟸𝟾𝟹𝟼𝟶𝟾𝟼 𝟺𝟶𝟶𝟶 𝟷𝟼.7 𝟷𝟻.𝟻𝟹𝟸𝟸𝟻𝟾𝟿𝟸 I have the 'digital' version of this device and will be trying it out tomorow in a plastic unventilated but spacious enclosure at 2kW for about 90 minutes. We'll see if it overheats. I think that little heatsink would benefit from active cooling. The usual disclaimers about the chances of this actually being a genuine ST part apply.

[@abousamah1967]

Thank u very very mutch Full explnation and schamatic drawing

[@TheSukitani]

It all goes "whoosh" over my head, but it's still very interesting.

[@fizalex6612]

I basically spent my whole Saturday watching your videos, no regrets.

[@bikefarmtaiwan1800]

Great video Clive. SCR/ Tiacs are fascinating things. You might have added how the capacitor manages to allow the dimmer range to be extended by phase shifting the signal to the diac. Always fun to watch your channel

[@Isaiah1v18]

Great explanation. Thanks

[@LazerLord10]

Question: Would I be able to use one of these to power the heated build plate of my 3D printer? It's essentially a 1.8 ohm resistor, and I'm not sure if something like this would work. Of course, it would trip a breaker if I turn it up too high, but I'd be running at ~24Vrms and ~400 watts. Does this sound reasonable?

[@SunnyJulienDivine]

I don't think this will work on 24V~ as it is designed to work with mains voltage. Since your resistive heating element is low voltage and high current (17 A), you can rectify the 24 volts and use a NE555 + mosfet for power regulation.

[@LazerLord10]

Sunny Julien Divine No, I don't mean 24V input, I mean 24V RMS OUTPUT. The whole point is that I CAN run the heater on AC, so there is no need for a separate 24V switchmode power supply (which is what most people do). I was thinking that this would be a better solution. I already ordered a similar one, though.

[@SunnyJulienDivine]

This device is not suitable for your intend as the minimum output voltage is around 33 volts. It would cause a current of over 18 amps and therefore blow the fuse and maybe the SCR if you turn it up accidently. The better solution would be an extra transformer or smps for your heating element.

[@SunnyJulienDivine]

Look at 15:04 then you will understand why using this on 24V is not a good idea.

[@LazerLord10]

Sunny Julien Divine Ah, okay. Well, I already bought one, so I guess I'll try it out and see what happens. It was cheap enough that if it dies, I won't be out much.

[@mogomega8825]

Thank you sir! this is very useful 👍

[@danielescobar7618]

Im in a rabbit hole trying to turn the speed of my die grinder down. I used to be into electronics when i was young, this is very cool. I may try this one out.

[@sergeyivanov3453]

Today I've learned something new

[@ronmoz5815]

thanks you sir for your demonstration

[@karloflochalsh8817]

I have noticed that you sport a sticking plaster or a small cut most times lol, not to distract from your excellent understanding of your presentations.

[@badeadrian]

Just bought one today from Amazon...I need for my meat grinder machine to slow down the speed when I'm making sausage next month before Christmas 😏

[@jamieh9351]

Forgive my ignorance but is this the AC equivalent of a PWM circuit?

[@bigclivedotcom]

+Jamie H Yes. The phase control is similar to the mark space ratio used with DC PWM.

[@jamieh9351]

Thanks Clive. Great videos on your channel by the way!

[@Ni5ei]

+bigclivedotcom So if I understand correctly, it doesn't actually lower the voltage? When using a 220/240V incandescent bulb on 110V you can massively extend its lifetime. Will using a dimmer circuit like this have the same result or does the lamp still get 220/240V spikes?

[@bigclivedotcom]

+Ni5ei It lowers the power dissipation of a lamp, so you could use a dimmer to nudge the power down for longer lamp life, but efficiency of the lamp would fall dramatically.

[@nvmnvm8821]

+Ni5ei 5% lower power to an incandescent is generally considered to double the lifetime of the bulb. Any spikes that it might receive from the circuitry would (probably) be much too short in length to actually influence the intensity and therefore does not effect the lifetime.

[@manitoba-op4jx]

i once opened an old lamp dimmer switch and it had a 100k resistor and a 1nf cap snubber

[@glenwoofit]

Phew, I'm glad you mentioned Radio Amateurs as I was shouting at the video when your said suppression chokes are not needed these days. Can you do a video on Power Line Transformers and tell people not to use them for exactly the same reason. Cheap Chinese ones won't have the filters in and render thousands of pounds worth of sensitive radio equipment useless.

[@g7mks383]

Thanks for another great video. I have just got one of these to use on my solar immersion heater control. I see many different suppliers of the same thing but they show completely different connections to what looks like an identical unit. Any input would be appreciated, should not the fuse be on the input?

[@adadmohamedcherif192]

Thank you , me too I've learnt something

[@lucheins872]

this is amazing! I almost bought one.. was not convinced that it was a substitute for a variac. I was wondering by myself : what would Clive have to say about this thing? like you read my mind. Thanks!! great review. Can you hook it up to some different stuff like led lights and normal lamps and a ventilator motor for example? realy like youre vids!!

[@keithjurena9319]

I have a 2 kW variant of this triac..use it to control the speed of a 120 volt PM DC motor. It feeds a full wave bridge rectifier with a large run capacitor to help smooth the resultant DC. works but still noisy. need to add a choke ib series to keep from blowing the fuse.

[@Zig285]

I just ordered a SCR and rectifier to control a 130v DC motor with FF 1.0. How did you size the capacitor? I'm not sure how to figure that out.

[@garthdaddy7438]

i think you will find this a SCR not a triac. Replace this with an triac and double your power and decrease the noise.

[@samuelolteanu]

I'm using this very thing to automatically limit a boiler power (from home assistant with esphome) so that it matches pv solar. I considered using a digital potentiometer but there were complications, mainly too much heat dissipation, and maybe live mains on the microcontroller so I ended up using a servo. After 1.5 years of continuous adjustment the pot gave up so I replaced the whole thing wih something very similar but this time detachable thus easily replaceable potentiometer. There are better sollution but this works for me. Needs active cooling.

[@maximiliano56]

Indeed friend, i allways use 47ohm in the snubb

[@edmanrapperu]

I'm pretty sure that's a cheese grater, Clive.

[@1pcfred]

Make America grate again!

[@macey75]

Ya think?

[@jamesellis5445]

Some grate more than others.

[@NavinBetamax]

@@jamesellis5445 ..I Grate with you on this !

[@jamesellis5445]

Navin Kotadia that's great, thanks✌

[@jimnoonan7511]

Hi. First I want to say I love your informative and engaging vids. As an electronic dunce I have learned a lot. I am trying to control the speed of a universal motor and am now happy, thanks to your material, that I will use a pwm circuit similar to this but I am really struggling to work out what needs adding to the circuit to allow torque to be maintained at low speed. Despite a lot of research I can't find an explanation I can understand of what is required to maintain / change the torque. Is that something you could help with please? Thanks and keep up the great work. Jim

[@VorpalForceField]

in regards with the 4.7k on the snubber .. I believe that to be intentional. If that resistance is too low it would defeat the benefits gained from the rectifier which in it self provides some snubbing.

[@kevito666]

I think it can also prevent arcing when changing the speed under high load? Being too of a value small might cause the system to become unstable since the bridge rectifier is doing a lot of low end stability.

[@MRrwmac]

So if I wanted to use this on an induction motor (such as a treadmill motor), what would you suggest I add in order to get good variation of speed from 0 - it's maximum? Thank you very much for your great videos!

[@GeorgeGeorge-xj2bc]

I tested with the inductive motor of air fan and angle phase triacs does not work at all.

[@amtsgedicht]

Thanks for the nice Analysis - I don't like the screw so close to the high voltage track on the backside close to MT1. This could easely short out and put the heatsink at high voltage.

[@hadireg]

I'm still an AM user and indeed have trouble with anything using chopped signals, good side of it, I know more about the LEDs build quality this way :)

[@birdiemcchicken1471]

Power Controller, Triac, Bridge Rectifier. Technobabble!

[@FireballXL55]

I have had a quick read but did not see any comment on this. The reason that glass fuses are not good for high current interuption is that the fuse wire vapourises and can coat the outside of the glass forming another fuse link. The problem with that is the glass keeps it cool so it needs a lot higher current to blow and this will shatter the glass leaving you just the end caps.

[@Mike-gr2ok]

Could you please run a test on this module ie on a power drill or similar thing ??

[@DanielFSmith]

The heat sink screw looks excitingly close to a live track. I'd be trepidacious installing this near ants! If the case is grounded and touching the heat sink, it might be on the wrong side of the fuse as well, but I couldn't really tell from the picture.

[@michaelnobibux2886]

The bridge rectifier reduces hysteresis on the potentiometer by firing the triac with a pulse of consistent polarity.

[@lawrence1md]

@bigclivedotcom- I have one of these controllers, have you checked the output voltage on it? When the unit is at 100% it is off by 20 volts. Is this because of r1 in your diagram? Great work, I'm always looking forward to new videos!!

[@YodaWhat]

+Matthew Lawrence, you know this how, exactly? Did you use an oscilloscope? Or perhaps a peak-capture circuit? I bet not. True RMS is the least quality meter to make such a claim. Cheap meters WILL give you erroneous readings and even a lot of devices which claim to read "true RMS" (like Kill-a-watt) are lying like dogs. Most likely the inevitable turn-on delay in the first part of each half-cycle is confusing your meter.

[@jamesfair9751]

YodaWhat I know exactly by means of my Fluke multimeter mine was only 15 volts low. I assumed like buck/boost converters it absorbs some of the voltage in the circuitry and heat loss an such.

[@brianlittleforest631]

Yeah those outer cases seem to be super common. I've seen them housing pwm controllers and power supplies myself.

[@Robothut]

Great one Clive, I'm in my 60's and have built AC controlers all my life but never seen this set up before ! I think the snubber ressistor is wrong and maybe thats why they were selling them off on Ebay, cheaper to sell them than to repair them.

[@mrlazda]

+Robothut It is not wrong value, it is relatively common for modern TRIAC (it just show someone did homework instead putting random values). Low value of resistor is wrong way in designing rc snubber for TRIAC it will increase turn-on stress which with low value of resistor can damage the TRIAC. Picking components for TRIAC rc snubber is balancing act, but using better TRIAC will lead to greater values of resistor.

[@bigclivedotcom]

+Miloš Lazović Could you point me to a schematic on the Internet where such a high value is used? The purpose of the snubber is to absorb a transient that could exceed the DV/DT rating of the triac. The triac used in this unit is a normal non-snubberless one, so would require a typical snubber combination. The 4700 ohm resistor is going to severely limit the ability of the capacitor to attenuate the transient. Even with a 100 ohm resistor and the capacitor charged up to peak mains voltage the current would be limited to a tiny portion of current not exceeding around 3.5A. That's nothing to a 40A triac with a peak current pulse rating of around 400A. Especially when the capacitor is a mere 100nF.

[@mrlazda]

bigclivedotcom first that pop on my mind is ST AN437, and you will see why they use high value of resistor and why low values are not desirable

[@abdulshaffay1706]

bigclivedotcom capacitor volt 100nf and 150nf

[@robertlane9574]

Miloš Lazović ñ

[@Jeff5263]

I am an amateur radio operator and I had a weird experience with a touch lamp. If I transmitted on my radio in the HF bands (3-30MHz) when I unkeyed the radio I'd get a noise that started near the frequency I was on and would slowly drift up in frequency. If I tuned a little up or down I'd get away from the noise so it was like a carrier wave. It turned out to be a touch lamp I had that wasn't even on.

[@stargazer7644]

Touch lamps should be illegal. I had horrendous interference all across the HF bands that I eventually tracked down to a touchlamp in a neighbors basement 5 houses down the street.

[@rainbowananas5040]

Very addictive videos! :) Anything about Chinese 12V 80A pwm motor controllers? Had a similar casing altough larger.

[@saddle1940]

Nice video and explanation. The high voltage clearance around the triac legs looks a bit dodgy (small). Also, I'm not one for trusting the isolation clearances of a cheap carbon pot ( I know they say 750v, but I've seen the guts of pots like that fall to bits on more than one occasion).

[@S1kje]

I'm hoping that I'm not the first to realise that 10 amps on 400 volts is 4kw.

[@dougerrohmer]

On a resistive load, yes?

[@0x8badf00d]

Why would you use this between two phases?

[@jelleklinge9743]

@@0x8badf00d I think you actually could use it between phases, but Chinese are notourious for stating peak currents, a 10A fuse needs time to heat up and burn so in theory it possibly could conduct 4000w for a short time. I would love to run my 4kw heat element on this thing to see how long it lasts. and see if lets say 10A at 240v (2400W) of inductive load for an extended amount of time overheats the circuit. If not this is a real dealbreaker for my homebrewing kit.

[@mihailo.matejic]

Hi Clive, I've got a question regarding live and neutral inputs. I got basically the same controller (except it's a digital one) that has marked L and N input/output on the chassis itself, so I was wondering if it would work if live and negative lines are switched because I'm from EU and our plugs are not polarized (you can plug them both ways)? Or is there any other component that can I use before this controller in the circuit to make sure that live input is always live, no matter how I plug it?