Reverse engineering of a mains power controller.

Test and investigation of a phase angle control motor speed controller from China.
There are two components on this PCB that cost me MORE to buy individually than the entire cost of this assembled unit including shipping!
It's a very standard phase angle control module for varying the duty of mains powered devices like lamps, transformers or some motors (mainly universal motors).
The circuit does have basic suppression, but lacks the important choke that prevents strong radio interference, especially on older AM radios.
Other than that it's a nicely built module using a textbook design and a beefy triac on a chunky heatsink. They claim it's rated for up to 2kW, but I'd be wary of using it on anything near 1kW continuously.
Note that the triac used has an isolated tab but that's not always guaranteed, so the heatsink should be regarded as being at mains voltage, as should the whole PCB. If the module is mounted on a metal panel (using the potentiometer nut) then the panel should be grounded/earthed for safety.

[@gskempe9]

What a nice presentation and reverse engineering job. I just purchased one of these and was about to reverse engineer the circuit when I came across your presentation. You did an excellent job, saved me some time, and gave me a better understanding how the circuit works. Thank you very much. Respectfully, Steve

[@Harkendown]

Hi. I'm no electronics engineer but I do have a need for these regulators to control motors of various woodworking tools I am building. I have bought 10 of these to date, from various suppliers and prices from 1.50 to 3.5 gbp. Only two of the ten do what they say on the tin. The other eight have output voltages from 200 to 240 (not 50-240 as promised). I found your video very edifying and as a result of what I learned went back to re-test the faulty ones to make sure I was testing under load and with minimised potentiometer setting. All I can say is you were lucky to find one that worked! Thanks for the video.

[@cornelisspronk4068]

I have used this to control the heating element in a homebuilt coffee roaster from a 230 V 1500 W paint stripper. To roast the coffee it runs for about 12 minutes at 650 Watts. The BTA-600 has failed after several months. I have replaced it with a BTA-800 a couple of years ago, and it is still going strong after using it at least every other day. The line voltage here ranges from 230 to 240 V. The ever changing line voltage is enough to mess up the roast, so I needed to tweak it. I removed the 1 Meg Potentiometer and replaced it with a 50K potentiometer in series with a 320K fixed resistance. This allows me to keep the temperature in a narrow range for a satisfactory roast.

[@koningbolo4700]

Can this type of PCB useful to limit the power use for a heating element or are other PCB's more efficient? I like to limit the power use of a heating element in a solar powered boiler setup in a campervan... The boiler has from the factory a 500W element whereas the solar panel has only 450 Wpeak. It would be best to "tone down" the power use of the 500W element to say 300W for the solarpanel to be able to keep up better. Using a voltage sensitive relay to sense when the battery has been fully charged at which time the heating element is powered to take advantage of the "surplus" solar power... What do you think ? Can I use this circuit or should I use something else?

[@cornelisspronk4068]

@@koningbolo4700 I am using this power controller on 230V mains in the UK. I am suggesting that the BAT-600 is not reliable at a resistive load of less than half the full load of a 1500W element, but with a simple replacement by a BAT-800, the controller seems to be reliable. Your situation of very different, as your power comes from a PV inverter. There will likely be some complications if you "tone down" the power using this circuit.

[@faxepl]

Went to Ebay, bought 2 of those while listening to you talking :D

[@johnjurotte7256]

DERP?? That's a word that we don't use in Australia. I will add it to my vocabulary. Thanks again for another great video

[@paulsengupta971]

I think it's a word in internet-ish.

[@GKVVx]

Your analysis is very good and helpful for needy repairs if any. I purchased recently one from China. It is working good for my mini drill (220v, 350w 2600 rpm) which I use for day to day minor works and also for my Bosh angle grinder 600w 11000 rpm (to the reduction of speed upto 50% ). Any way my other Drill Bosh 13 mm has got builtin speed control. Thank you. With regards - VG Krishna, from India.

[@Peter-pu7bo]

Hey big Clive, I can't thank you enough (well I will see if I have you in my patreon list) there is so much rubbish out there and your DETAILED explanation helped me so much to solve my problem. Cheers and all the best to you stay healthy.

[@KarldorisLambley]

i found triacs confusing. mainly because of the all the names i used to mix up - triac, variac, varistor, thermistor, thyristors, thyratrons, and klystrons. i know they are all very different things. now. this vid was fantastic, during which, i made copious notes. i have finally understood triacs. the circuit made it all crystal clear. i want to buy a box of them now to play with.

[@carmelpule6954]

For resistors in parallel 1/R= 1/R1+1/R2 Hence 1/R-1/R1= 1/R2 (R1-R)/R.R1 = 1/R2 Hence R2= (R.R1)/ ( R1-R) R2 = ( 406,000* 2,000,000) / ( 2,000,000 - 406,000) R2= (406*2000)*1000/(1594) R2 = (812,000) / (1594) R2= 509,000 So the control resistor is a potentiometer of 509,000 ohms .....................where 470,000 was close enough. A good logical calculation by the narrator. Well done.

[@williamsquires3070]

No, it's closer to 500k: (2M x 500k) / (2M + 500k) = 400k. Which is closer to the 406k, than if you use 470k, which gives: (2M x 470k) / (2M + 470k) = 380.56k.

[@Firecul]

From what I remember (I haven't done this for 9 years now) the knob pot looks like 510kΩ.

[@BigClive]

Others seem to concur, so it probably is a 510K pot. Thanks.

[@Firecul]

No problem, I'm guessing they might have noted the formula but just in case. 1/Rtotal=1/R1+1/R2+...

[@alastairbarkley6572]

It's a single phase shift triac dimmer which will give erratic operation at low triac conduction angles - a nuisance for lamp dimming, more serious with motor control. The so called 'hysteresis' effect. The 100n capacitor suffers very heavy loading as the voltage across it collapses when the triac fires. Solution - a double phase shift circuit, which involves only two additional components, a 1/2 watt resistor (typically 15k for both 120v and 240v supplies) which connects between the junction of the existing 4.7k resistor and 100nF cap and the left hand diac terminal. The additional 100n cap goes between the left hand diac terminal and Neutral. This greatly reduces loading on the original cap and improved operation at 'dim' or slow speed triac settings. The second 100n cap needs to be prooerly voltage rated - same as the first one. This is a bona fide mod found in all the thyristor books.

[@alastairbarkley6572]

Thank you Clive. Pedant point but the snubber network you mention is not 'a filter'. It is indeed to prevent false triggering of the triac with inductive loads. Basically, the triac itself has an internal capacitance (gate to MT). In an inductive load, the voltage across the 'inductor' is not in phase with the current flowing through it. If the current flowing is zero but the voltage is high, the gate 'capacitor' can acquire sufficient charge to trigger the gate (and hence falsely trigger the triac). The faster the change in voltage (dv/dt), the greater the risk. The snubber network is simply a series RC which reduces dv/dt.

[@harviecz]

Replace pot with photoresistor, heatshrink LED to it, connect led to arduino. BAM you have PWM control for universal motors. Add another LED and phototransistor to read RPMs from motor, write some PID code, BAM you have closed loop feedback motor control!

[@MegaJmanjman]

Harvie sounds interesting! Have you actually implemented this?

[@CaspaB]

A photoresistor won't take 240V. As you said above, "BAM". Maybe 2 in series, so long as they were illuminated equally.

[@minkorrh]

Excellent info! I have a few of these kicking around and was just going to stuff them into a plastic box to use as a hacked up soldering station and hot air gun. I was wondering about the potential for electrocution when i noticed that 2 pins of the pot are directly attached to one side of the outgoing AC. Thanks again for another entertaining/informative video. Esecially enjoyed the 'Hitachi' teardown. Had to have a drink to Lily the Pink after that.

[@Tocsin-Bang]

I built a speed controller using this same circuit a few years back Sadly its died for some reason (probably not a big enough heatsink), but I think I'll buy one of these and just add either a small fan or a bigger heatsink.

[@geofflotton5292]

The description says it all. " This controller uses novel bi directional high power SCR. It can be very convenient adjust the current up to 25A and solve the over current problem of the heating wire resistance is too small in the case of cooling causing good.

[@m8e]

R2=(R1*Rtot)/(R1-Rtot) R2=(2000000*406000)/(2000000-406000)=509410.2 510k ohm

[@BigClive]

Good job. That is a standard potentiometer value so it probably is a 510K pot.

[@m8e]

bigclivedotcom Thanks. I do actually remember how to get the total Ohm from known resistors in parallel. Just add the inverse of the resistor values and you get the total in inverse. (1/Rtot = 1/R1 + 1/R2...) But I just searched for "parallel resistor calc" to get that formula with an unknown resistor and known total.

[@ZeedijkMike]

+bigclivedotcom In the old days (before the 90ies) potentiometers used the E12 (10%) range (or even the E6 (5%) range). So 470k. Now the they seem to have their 'own' range. So the value printed on the pot would probably be 500k (not 510k wich is the E24 (1%) range.

[@squidcaps4308]

Yup, had to check myself too... Now all i need it to filter the output and i'm good to go.

[@winsock]

1/Rtotal = ∑(1/Rₓ) 1/406000 = 1/2000000 + 1/x 1/((1/406000)-(1/2000000)) = x 406000000/797 = x Due to Standard EIA values the closest probable value would be 510kΩ x ≅ 5.10E5 Ω (510 kΩ)

[@kwils6685]

+Andrew Querol Even tho I understand your explanation and it is correct I also see it as almost being some secret unbreakable code by at least most of the people I know. Stephan S. explained it in a much more helpful if not tiny bit minimalist way.

[@winsock]

Yeah, it doesn't help that it's written out in text form too. I think it would look less intimidating if I wrote it on paper and didn't have to add so many parentheses and didn't have to use the sigma letter to denote summation and instead could've just used ellipses plus subscript n. But for some reason Unicode character U+2099 doesn't work for me :(

[@winsock]

+K Wils Maybe I my highschool electronics teacher(read as simple electronics, the final project was a strobe light with less safety and isolation than a cheap shitty pink charger 😜) was really effective, or I just have really good memory.

[@winsock]

+K Wils To be fair most people know it as the emoji organization now -.-

[@kwils6685]

+Andrew Querol Oh your right emojis! We only used Unicode to put umlauts or copyright symbols or a few other things in documents didn't emoji much myself.When i asked some people if they knew what Unicode or emojis are I was shocked when one asked if I was talking about ascii? I asked him why he knew what ascii was and he said back in the day before monitors everything used to come over the teletype or line printer and they used to print ascii art nudes on green bar paper! If I can just think of a way to get nudes into a discussion on lissajous patterns I might get someone to talk about them!

[@abousamah1967]

Thank u very very mutch Your explnation is enjoying and very simple And your attachment schemes make the episode very nice Thanks

[@jemjack35]

Hi Clive thank you very much, it is a universal type washing machine motor I will let you know how I get on when it arrives at the end of the month. best wishes Jem

[@kengamble8595]

A little late for the party here but I now have ten of these and for the reason you mentioned, I paid one dollar a piece for them ! I use a lot of 120 volt universal motors and they work great for that, haven't tried on 220 yet. When I saw the price I was wondering if it might be a scam and would never receive any but after getting two I got more ! Sure don't know how they do it so cheap ! ??

[@argylekennethdobbinsiii1565]

This is pretty much the exact circuit used in Cheaper Solder Iron stations to control Temps. Some use a version of the Westek 6077B 200-Watt Manual Dimmer circuit to achieve this in a somewhat smaller package.

[@mohanvvip]

"Luvley"! I think that's how you'd describe your video☺️. Thank you, very informative. I'm about to convert my 110V Dremel-workalike to run on 240V by changing out the speed control unit for one rated to work at 240V. Hopefully the motor won't burn out.

[@ianhelsbyservices]

Did you get it to work? I'm using the speed controller from a Dremel type tool to vary the speed on a small 220V DC compressor motor. I need to run it slow enough so that the reciprocating piston can shake aerosol spray paint. I watched this video to find out how triacs work and left smarter. Thanks Clive.

[@mohanvvip]

@@ianhelsbyservices Sorry, not yet. Don't feel like sacrificing a perfectly good tool just because I don't want to lug a heavy transformer around.

[@ianhelsbyservices]

@@mohanvvip i use 110v angle grinders as they're cheaper second hand than 240v. To avoid carrying the transformer I use a long 110v extension reel. Would running your tool at 240v double it's speed? Perhaps a smaller transformer could be used. One that's matched to the current requirement of your tool.

[@mohanvvip]

@@ianhelsbyservices I could probably use an incandescent lamp in series. A really serious electronics engineer would probably warn me about the surge current at startup etc, but I think a series resistance would work better than any triac for powering the universal motor for short periods, the only disadvantage being that quite a bit of power would be dissipated in the lamp. I think the motor draws 100 watts.

[@anthonyshiels9273]

The formula for calculating a number of resistors in parallel is given by 1/R = 1/R1 + 1/R2 + 1/R3 + ... Series capacitance has the same format. With a University Degree in Physics and Chemistry I never used these formulae since I was in secondary school which I graduated from in June 1974! I had to check them on Google.

[@vincentxgolden6624]

Mostly inductive loads, motors, transformers ,and such sometimes variable D.C. for bench use and of course kluges. Enjoy your channel I do

[@fireracerworkshop8251]

I have tested this speed controller upto 1.5 kw application and it works well

[@stephanstanisic2007]

1/total = 1/R1 + 1/R2

[@jasonparrish8488]

Every time I watch one of your videos I feel like I'm being taught something new. I guess you could be called the great teacher? What do you think.

[@kiddmaxson7865]

I got 2 of those things from China, mine look exactly the same but rated for 110v. The strange thing is the Hz, it ranged from 60-180.

[@kiddmaxson7865]

On the output

[@JoeGP]

on mine the 'knob' says 500K, i tried it on an angle grinder and it's pretty rubbish (only like the last 10-20% of the adjustment works). I saw somewhere else that i need to connect an 'inductive load' (if i remember correctly) to make it work better, that being a 2k 10W resistor, but i can't remember how it was supposed to be connected (probably in series). Also i have a cheap variable speed drill press (pillar drill) on which the speed controller died, unfortunately it's all incased in epoxy so i can't fix it, it's probably something very similar to this but with no heatsink. So i bought one of these to use with it, and it works a lot better than with the grinder, all of the adjustment works, it just doesn't slow it down nearly as much as the original speed controller, so i probably have to adjust that trimmer pot.

[@ghettomining]

I just bought one if these with a 2kw inverter for a blender motor that was a 2 speed now variable and off on an rc boat.

[@beachsandinspector]

I look at all your videos, sorry I usually forget to press the like, thanks for the time you spend in doing your videos, I look forward to all your videos. Oh and the way your VAT works you keep having 20% added on in every stage of the delivery process hence why you get slugged so much.. a friend had a company that imported electronic components, he got the items in bulk, sent them across to France and to be packed in smaller packets and he could then sell the items cheaper than what he bought the bulk items as the value adding was not in GB and he was exporting to France and re-importing at a lower vat rate.. strange your VAT there.

[@ThePillenwerfer]

Likewise - always interesting and entertaining.

[@elvinhaak]

That is not exactly how it works. It is Value Added Tax. If you have a company (registred for doing imports and exports), the only VAT is payed is to the difference in pricing to the end-user (private customer, not a business since they will be able to get the VAT back again). At least in Europe... how it will be in the soon be not EU-UK ??

[@rashadabdullah9769]

Im looking at buying one to control the speed on my grinder. But very skeptical because i dont want to risk killing my grinder like 3rd party chargers do to iPhones (*・～・*). Right now on amazon these units are $10. Im debating whether i should buy the triac's and diac's and build one myself. You pointed a few things that correspond to the reasons why 3rd party charges kill charging chips on iphones. They are not isolated and insulated properly. Like your explanation of the triac and the wave. Im willing to put some money on it if you willing to design a solid reliable unit. Not now tho, most likely late summer to fall. Winter here is extremely rough lol. Great video man.

[@rockyfosgate]

Could this be used in conjunction with a full bridge rectifier to make a cheap dc power supply?

[@finbob08]

I would also like to know this ^^^

[@Gengh13]

Yes, but with a serious caveat, it wouldn't be isolated, it would be mains referenced and if you use a non polarized mains connector(or wire it incorrectly) you could end up with a negative DC wire of your power supply at live voltage ready to kill you. Do not do this if you are not fully aware of the risks.

[@evilmonkeywithissues]

Given that this is most likely made using the cheapest parts that could be sourced, I imagine that the tolerance on the potentiometers are going to be in line with the 5-10% standard, so the value of the unknown potentiometer is probably 520k ohms.

[@muhammadriazkhokhar561]

Excellent explanation.

[@astrofishwalk]

When you had it wired up live was linked across input and output. I can't remember what is connected to the tab of a triac but it may be raw power. If so this may be why I vaguely remember seeing diagrams showing things wired as you had - lives to the directly linked terminals. If the triac doesn't have an insulated tab this may be important as it could keep the heatsink at neutral rather than live.

[@kenstreet1769]

how would one increase the max load on that speed control? Say to run washing machine motors. I have some power tools I would love to add speed controls as well 2 hp motor or about 15 amps. I would build mine to handle 20amps. How ever I really enjoy watching your videos. I always end up learning a new trick or two. Best of all your your videos don't put me to sleep. Thank you so much for all your hard work!!! I try to pimp your videos out to my friends when ever possible. 👍

[@houtjeboom]

I have a question. I bought one of these only it has only 2 terminals for input and out put. How do i connect that????

[@randomisoty422]

(If you don't already have an answer) Chances are, connect the neutral of your input and output together and connect the hot wires to the board (It only needs to switch the hot wires, so the neutrals can completely bypass the unit)

[@killer1479]

good old cliveCAD episode :) had a gander at your web page earlier and saw a few things i may buy in the future :D

[@BigClive]

i really should add more products to my web shop. And probably revise the prices too, since they look high by modern standards. The RGB kits have found their way into the weirdest places, including the costumes on some of the Disney illuminated parade characters.

[@killer1479]

bigclivedotcom in my eyes the prices seem pretty fair :) but do bring us some more cliveCAD to, i like watching them :D and i like how you explain things clearly also

[@girishthanekar958]

Hi !! You are fantastic in all.. please guide me on following, 1) Can this regulator be used to control 750w angle grinder for continuous work? 2) what should be the minimum RPM of grinder to be set to avoid burning of carbon brushes? 3) additional cooling fan required? 4) other precautions if any?

[@user-vn5id2it2x]

Hi, this can handle upto 6000w

[@WaltonPete]

The price of stuff from China and Hong Kong on Ebay is astonishingly low - it costs me as much as that power controller just to post a small card to the US! I know which I'd rather have!

[@Lykaotix]

Damn it, I'm so far behind! I literally bought one of these around 2 months ago and I still haven't messed with it 😅

[@personalpersonal1547]

I bought 5. 2 for pump control and one for light dimmer and a spare. I found I needed a resistive load (lamp) in parallel with the pump to get a useful speed adjustment range. Can any on explain why and what resistor would I need to replace the lamp?

[@rico2207]

Its probably in series the two potentiometers..so one can influence the other..fine tuning or fine biasing..??

[@MegaJmanjman]

Hey Clive, thanks for the video. It actually inspired me to use that exact module as a dimmer in a lamp project. It works fine so far but i got one issue. The Lamp still glows with the pot (and the threshold pot) all the way down, so i figure i have to tamper with the resistors a bit. Do you have a tip for me with value to replace the 4,7k resistor? Or should i measure the voltage across the bulb and calculate the value somehow? Thanks!

[@BigClive]

Johannes Elsinghorst Is it just glowing at very low level? If it is then it may benefit from increasing the value of the 4.7K resistor. It may even be that the trimmer or potentiometer are too low a value.

[@MegaJmanjman]

Yeah, just a dim glow. I'll try to increase the resistor and see where that takes me :-)

[@fede142857]

I found a very similar looking heat sink (probably the same type actually) from a supplier called "International Aluel". It claims to have a thermal resistance of 11 °C per watt. The module, running at 240V with a load of 1 kW, would dissipate about 4.2 watts (applying the "1 watt per amp" rule of thumb), which means that its temperature would rise to almost 46°C above ambient. So even 1 kW might be too much for that tiny module! I don't know where the 2 kW limit came from (perhaps the absolute maximum temperature the TRIAC can handle?)

[@fede142857]

My bad, upon watching again I realised that the heat sink looks more like a slightly smaller part from the same supplier. Thermal resistance is actually *14* °C per watt. Temperature of the heat sink and TRIAC, at 1 kW load, and applying the same equations, would be *58* °C above ambient.

[@SuperBlackReality]

BTA16 600B is rated at 16A from what i can found on google, so probably from that someone calculated just the power

[@vincentxgolden6624]

SORRY The "snubber is in place to limit the di/dt across the triac when controlling inductive loads and retriggering the triac

[@BigClive]

dv/dt. Change in voltage versus change in time. Sharp edge transients can cause false triggering.

[@greenleaf35]

Would this work to make a cheap soldering iron adjustable

[@SuperBlackReality]

I got that controller and on the main potentiometer there is a text "B500K"

[@Landrew0]

I bought one of these after seeing it in your videos. It cost me $2.10 CAD with shipping included. I wired it onto a box, and it works quite well as a dimmer, but controlling a fan with an induction motor, it hums quite loudly. I'm not sure the cause or the cure.

[@BigClive]

A motor will hum quite loudly on phase angle control because it is being switched with quite a sharp edge mid cycle. Some motors will not work well with a simple dimmer like this as the back EMF from the motor may cause issues with the triac not latching properly on one or both halves of the waveform. Then you have to consider switching symmetry and suitable RF suppression. For the trickier motors it's sometimes better to get a dedicated motor controller for that type of motor.

[@Landrew0]

I used a simple rotary light dimmer to control the speed of my range hood exhaust fan, and it works quite nicely with no hum. I assume it's also an AC induction motor, so why the difference?

[@acer33vv]

How about adding a solenoid on live load line it would make any difference ?

[@hackinblack7102]

you're not kidding; i paid 3euros for black anodised one of those heatsinks for a TDA2050 amp project, from a 'local' shop which has since shut down (wonder why...) just shows how much the likes of craplin/vapid /elephant14 etc make on the buggers..10p each for m3 spacer? why yes, i'll have a 1000 pc bag please.NOT!

[@armenariadanly4181]

nice job sir.

[@krisea3807]

I believe that one is 100 ohms 0.5 W and other one is 470 ohms 0.25W.

[@ammaralyasiri4191]

thanks

[@keithking1985]

Do all daics turn on at the same voltage or can you get them like zeners with different break downs???

[@gustavolopez3405]

EL ARTE DE LAS PALABRAS dice "INGENIERIA reversa" cuando la verdad es " copiarse" .

[@shahraj1918]

Thanks for detailed reverse engg. Can we simply replace BTA16 with BTA40/41 to increase its power level without any modification in circuitory or the oem circuit 4000W with a bridge rectifier is required as explained by you in a separate video.

[@BigClive]

You might need to scale up the other component sizes too, to deliver a higher current gate pulse. If you're trying to build something like the 4000W dimmer unit then it might be worth using it as a base for the project and upgrading the components.

[@lucifer._]

I saw these Regulators like the one you are showing titled: 220V 2000W Speed Controller SCR Voltage Regulator. _Will it work with 120V from the wall?

[@huberdaniel1]

yes it will but you can only regulate from 50v to 120V AC

[@lucifer._]

Great thank you. Nice video.

[@hbgpk]

Hi, would that be any good to slow down the speed of angle grinder (750W-12000 rpm)

[@BigClive]

+Grumpy Kid Grinders tend to use universal motors, so it should work. Just be aware that if it does fail it may suddenly make the grinder go to full speed.

[@jemjack35]

Hi Clive, it does work a washing machine universal motor fine, I have tested it. I wish to use mine on a small universal motor, it works fine, but there is a considerable difference in speed between forward and reverse. This is not a motor problem, as on another dc speed controller the motor has the same speed in both directions. Is this caused by the fact that this speed controller is AC? And would it be possible to turn this controller into DC. Would DC controller be more efficient than an AC controller? again thank you for your most interesting youtube, best wishes Jem.

[@mendistan]

Its 510k ohms

[@walt5797]

Hi Clive, How would one increase the wattage capability of this little board? Bigger heat sink? 2 triacs in parallel? Or no can do? I noticed that the 4000 watt units look the same but completely housed in an aluminium case.

[@harayz]

will this module be able to safely regulate the temperature of an 18W soldering iron?

[@BigClive]

It could, but an 18W iron should thermally balance at a good soldering temperature.

[@harayz]

i ended up wiring it to a socket that often use with a travel size (fast heating) clothes iron to desolder components off unwanted pcb.

[@geofflotton5292]

Some of these PWM controllers monitor back EMF from AC series motors to compensate for load on the motor. You didn't mention that so I am guessing this one doesn't. I am guessing different theory of operation?

[@EvilS0B]

Can someone please explain an issue I have with one of these 'exact' controllers please. I have tested it with various power tools with excellent results, so I know it is not faulty. BUT, when I hook it up to drive a MOT, I cant seem to measure the voltage or amperage correctly. My 'cheap-ish' multimeter (on AC) doesn't read 240v output from this controller until it is nearly 'full on'. So I'm guessing that is because it is not a 'clean' sine wave until then. If this is so, can I also not trust the MM readings (both volt and amp) on the output of my MOT when driven by this controller below full-on? So if anyone has any ideas/suggestions on how I can measure the MOT output, or corrections on my above statements or question I would appreciate it. PS Keep up the GREAT work Clive, I love it all ... except your ability to hold a PCB and solder and guide said solder to the right place with one hand makes me SOOO jealous!!

[@alastairbarkley6572]

These modules are fine for controlling brushed ac/dc universal motors - as you say. Universal motors are absolutely everywhere, vacuum cleaners, kitchen equipment, shredders and small hand tools. BUT.. these Chinese triac controllers are absolutely USELESS for controlling most ac induction motors - as you find on lathes, bench drills, belt sanders etc. Not only useless but hazardous too. Lots of YT channels give bad advice about this.

[@crocellian2972]

Clive, I worship you. International politics and finance are my bag. China floats is currency, illegally. Avoid the swamp.

[@gigio1274]

Hi Mr Clive, I'm Italian and is very difficult for me to undersdand all the explanation. I bought 4 pcb's as in your video and I'd like to have some information: - using it on an induction fan it works well, I can hear and see the speed modulation - using it on a brushless fan it doesn't work as I'd like, there is no big differences from maximum output and half regulation of the main trimmer. Regulating the main trimmer from zero to half the fan doesn't turn, from half to maximum yes. Why? I didn't touch the small trimmer, I must to do it? - What does the small trimmer? Many thanks and best regards ! P.S. Sorry for my english, I hope you understand all my questions. :-)

[@BigClive]

It may be that the brushless fan is a synchronous motor and will not run until a specific power level is reached.

[@RandomPsychic]

16:30 these are resistors/potentiometers/rheostats...not capacitors....

[@subodhshakya9880]

I bought same one but not working output and input same What is problem

[@kalpeshparmar165]

After 7th minute you said that it needs a choke, can you please tell me what type and what rating of choke can we use or how to make that choke for this circuit. And I need output only half of it, i.e. nearly 130v to 140v max, can I attach 100k or 200k ohm resistor in series with potentiometer (knob type) to achieve that voltage. Please also reply to your other video of dimmer. Thank you

[@phinok.m.628]

If it were 470K then the expected combined resistance would be 1/(1/470000+1/2000000) = ~380K Since it is 406K however, the resistance of the potentiometer should be 1/(1/406000-1/2000000) = ~509K so I'm guessing perhaps it's supposed to be 510K?

[@johndododoe1411]

Remember, these are variable up to the specified values, down to zero. No point going for an E24 value. Oops, YT recommended this ancient video from today's video in 2022.

[@phinok.m.628]

@@johndododoe1411 Fair enough, but he was trying to measure the "specified value". And just like resistors, potentiometers also sold in steps that make sense, considering the tolerance. To be fair, potentiometers usually have fairly high tolerances, so you're kinda right, it's actually pretty unlikely to be a E24 value. Potentiometers are usually sold in E6 steps, plus some round values, like 500k. And values like 100k, 500k, 1M, etc. are by far the most used. So the resistance of the potentiometer is very most likely (supposed) to be 500k, not 510k.

[@Mailmartinviljoen]

Im wondering if you set the blue pot to minimum output if it affects the max out put of the main pot?

[@fededim76]

Are there any flaws in wiring the live load to MT1 like in the schematic ? Many of the schematics which I have found online are reversed, they have live feed on MT1 and live load on MT2

[@BigClive]

It can be used either way round. The gate reference on the circuit itself must come from the MT2 side though.

[@fededim76]

Great, just another question about components: how much is the resistor's wattage ? From the video they seem standard 1/4W, but since I don't have the module in my hands I can't tell. Also I believe that the two capacitors are 400V at least

[@BigClive]

I think they were metal film, so closer to 1/2W in that size. It's always worth over-rating the components for reliability.

[@fededim76]

Ok thanks again!

[@acer33vv]

What's the voltage on pins of potentiomiter (knob) when using 220V AC? Also is it possible to substitute this pot for a digital one ?

[@rockyfosgate]

Any ideas why my one won't dim no more? It's just stuck on full power.

[@BigClive]

That usually means that the triac has failed short-circuit.

[@rockyfosgate]

Thanks Clive. Tested just about everything but the triac. I will give that a go. Cheers.

[@geofflotton5292]

Sorry. I know it isn't a PWM. I was chopping between websites and got my resistors and capacitors mixed up.

[@coleteets6814]

Hey @bigclivedotcom im going into cyber security, looking to mess with pcbs. got my jtagulator and about to buy a bus pirate, im working with a sound board for a little project just to get the fundamentals. Dont understand the whole electrical bits but studying the chips, scared to blow my toys up, Any tips?

[@BigClive]

Proceed with caution, double check anything you have doubt about online and if you do blow something up or brick it, then know that it happens to the best of us, so don't feel bad about it.

[@Ni5ei]

+bigclivedotcom I'm building a lamp holder with built-in dimmer for displaying these nice classic Edison bulbs you can get from China nowadays. Since it's for decorative purposes only I don't need the lamp to be able to be at its maximum brightness so I've put a 270K resistor in series with the main potentiometer so at the highest setting it's already dimmed to about half its maximum brightness. However, because of the added resistance I now have to set the secondary trim potentiometer much higher. This is all working great but I was wondering if this causes any negative side effects like putting more strain on the triac or dissipating more power that gets turned into heat.

[@BigClive]

+Ni5ei It should be fine. It's the same technique used for adjusting an upper motor speed on simple triac controllers.

[@pedroborges2672]

Well, I have a speed controller like the one you showed in the video. I have a doubt in the calls. at the current input and current output both phase and neutral connect at one terminal and the other. that is the input I have two terminals, whatever the phase link in one or the other, and the output the same thing, whatever the connection ?

[@newvaper3794]

i have the same controller and it has been working as a light dimmer...my issue with this controller is the 500k ohm potentiometer...since i purchased the controller i already have replaced the potentiometer thrice...i do not know what is happening but it seem the carbon inside the potentiometer gets damage easily...how can i protect the potentiometer from being damage in just a few weeks?...thanks.

[@koningbolo4700]

Can this type of PCB useful to limit the power use for a heating element or are other PCB's more efficient? I like to limit the power use of a heating element in a solar powered boiler setup in a campervan...

[@BigClive]

It depends on the equipment powering it. It may be easier just to use a lower power element.

[@koningbolo4700]

@@BigClive The heating element would be powered by a 1500W (3000W peak) inverter. I could install a different heating element (I probably will but the stock heating element has an anode (to protect it against whatever fresh drinking water can throw at it) I may even come up with a totally different way to plumb the boiler in... I intend to use the tank of the boiler to fill with coolant from the engine and the internal coil plumbed into the drinking water system...That way the heating element does not need an anode since it is submerged in coolant (which is anti corrosive and without any oxygen - to mention) This method of plumbing in a boiler is uncommon but not unusual... Bothe methods.

[@squidcaps4308]

just got the same unit and had terrible case of "oh no" when the motor froze, didn't do anything even directly connected.. the damn thing had seized mechanically just at that very second :) oh well...

[@user-yl5ri3ii9b]

Can a 110v cauterizer be run on a dimmer switch? It is a 60 watt soldering iron.

[@BigClive]

Only if it was a simple resistive heater. If there are any electronics, then no.

[@user-yl5ri3ii9b]

It is a 60 watt soldering iron.

[@youtubegoogle4163]

15:28 Challenge Accepted 👍 1/R + 1/2MOhm = 406K Ohm R = 1÷(1÷406,000−1÷2,000,000) = 509,410.28858218 Answer : Around 510KOhm

[@gingerelvis]

So is it safe to link this directly to a fused UK AC mains lead? Just as the listing says 220v input? Looking to control a universal washing machine motor with it. Great video by the way! Really clear breakdown.

[@BigClive]

+kingoginge Yeah, most of the 220V stuff (Chinese voltage) works fine on 240. Just keep in mind that there's no interference suppression on this unit.

[@gingerelvis]

+bigclivedotcom Cheers for replying. So what's the best practice with this? To mount unit away from the motor itself to reduce electromagnetic interference? Am I right in thinking that with a universal motor I should be able to maintain decent torque? Reading around these little things can get bloody hot so thinking I should put a larger heatsink on it, maybe even a small fan. Sorry I'm a quite new to all of this!

[@BigClive]

+kingoginge It's radio interference that is the issue. Proper dimmers and motor controllers use a series choke to limit the electrical noise produced. Less of an issue with digital radio and TV, but still an issue for older wireless receiver systems. Is the unit being run for a long time? It may not need any further heatsinking if it is used with a relatively low power motor for intermittent use. Of more importance is putting it in an enclosure to protect users from contact with its bare connections. Note that the heatsink should be treated as potentially being live, as some triacs do not have an isolated tab.

[@gingerelvis]

+bigclivedotcom Ah right, is there anything to be aware about with radio interference or anything I can do to isolate it? It's a universal washing machine motor 480 - 1700 rpm, I plan on powering a scratter I made to mulch apples for cider making so would probably run it in bursts of maybe 10-20 mins at a time. I will definitely enclose the unit just encase there is any juice flying around!!

[@BigClive]

+kingoginge If you got the motor out of a washing machine it may have had a suitable suppressor where the mains came in.

[@lumen5699]

Sir is the light dimmers can control current? Is it increase or decresw current level?

[@BigClive]

It reduces current by turning the load on and off during the mains cycle.

[@lumen5699]

Thank you sir..so its not inter fair voltage?

[@Qaiserhayatkhan]

Nice

[@minkorrh]

20% VAT???? Wow I thought 13% hst in Canada was bad enough. At 20% the only added value is to the governments coffers.

[@arnoldnazaire6154]

Can I use that to control the ampere of a spot welding machine made of microwave transformer?

[@new2wood1]

Great vid, do you think this will be ok to use with a washing machine motor. i'm making a edge sander i have the motor but need a controller and this sounds great,. subscriber

[@sup3rbird]

+new2wood1 I was wondering the same thing and will it affect torque?

[@BigClive]

+Harry Irvine Phase angle control is often used to control washing machine motors. Torque will be a bit variable, hence why the washing machines often use feedback from the motor to regulate the speed dynamically.

[@scc3215]

O potenciômetro é de 510kΩ ((x * 2*10^6)/(x + 2*10^6)) = (406*10^3) x=510kΩ

[@rahulbhaskar4179]

Sir, the Knob potentiometer is 500k not 470k. I can tell it because I have this dimmer.

[@laikospalmos4810]

Hello from Greece, I get to know the name of triac.

[@ammaralyasiri4191]

sir how work Trigger Switch for Drills

[@BigClive]

Modern trigger switches use a MOSFET as the main switching component and electronic circuitry to drive it with a pulse that varies in on to off ratio to control the power. (Pulse width modulation.)

[@jemjack35]

Hi Clive, thank you for your excellent youtube on a mains power controller, I see that ebay even sells these for as little as 99p and upwards. Please can you tell me if this would be ok to control a washing machine motor. best wishes Jem

[@BigClive]

It depends on the type of motor. If it is a universal type (brushes) then it may work.

[@claroblanco2859]

Sir, can I use this to control the speed of an 800-watt 220 volts vacuum cleaner brushed motor?

[@MACYNET323]

Where find decent plastic box for these controllers?