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Pwm motor control Answered

Please send the circuit of cintroller


Jack A Lopez

22 days ago

I think I am seeing the same module, in these eBay listings,



and also being sold by Scam-a-zon, here,

The name for this module is often, "XY-L-1240" as printed on the board itself, on the lower left corner in your picture. Sometimes that name is seen printed in the text of product pages selling this module.

I do NOT have a circuit diagram for this, but I am kind of guessing that tiny 8 pin IC, in the middle of the board, is the brains of this power converter.

If we could find someone willing to spend 10 USD, and buy one of those from eBay, then maybe the numbers of those ICs are printed on them could be seen clearly. Also the wires those ICs connect to, could be seen too. Then we could be that much closer to discovering the secrets of this gizmo.

Downunder35mJack A Lopez

Reply 20 days ago

I had an almost identical looking one a while back, but only rated for 1000W and a max of 32V.
From what I remember:
Two mosfets in parallel for the positive AND the negative rail.
One mosfet each to drive the other mosfets.
The driving mosfets in my case were much smaller though and it also had a three way switch left-off-right, with the pot setting the desired speed.
The brains was also a bit bigger as it included a "soft start" - the part that wrecked it for me.

A quite common, Chinese approach for these toys is to simple put as many cheap mosfets parallel as required for the max output and then add a single or double transistor(mosfet to drive them.
The brains provide an adjustable PWM output and offers a very basic current limiting by tapping into the base connection of one set of power mosfets.
For me that meant the power supply was rated for the output but the soft start triggered the limit control on the supply by going overboard if the motor was started under load.
Most of the no name designs I find lately on Ebay and such sites are actually based on freely available circuits, often taken directly from places like Github.
Check the famous NanoVNA (network analyser) as a prime example.
Most of the induction heater circuits you find on Ebay that use a single and not a center tapped coil are still based the design of the induction heater I posted years ago LOL
They made some minor changes with the capacitors but that's about it.
If you want to mass produce a circuit then just post it online and wait a few weeks - it will appear on Ebay by Chinese sellers sooner rather than later - thanks to non existing copyright laws in China ;)

Jack A LopezDownunder35m

Reply 19 days ago

It turns out the "brains" for this board is actually a 555 timer. Also, for this one it is not a matter of transistors driving transistors, but rather all the signal, for driving the gates of all 5 MOSFETs, is sourced and sinked by pin 3 of that 555 timer.

Actually, OP posted some pictures of the board in his possession, and you can look at these, and see if you're seeing the same things I'm seeing.


22 days ago

This are the more pictures of the device which circuit dia gram i need please provide me

Jack A Lopezavoymaity63

Reply 20 days ago

I looked at these pictures, and I mapped out some of these circuits, and I will tell you what I have learned so far.

The 8 pin IC, in the middle of the board, is a 555 timer, and this is what actually makes the PWM signal that drives the MOSFETs.

I found a similar circuit, here:

The circuit there, and the one on your module, "XY-L-1240", both use this funny little network with a potentiometer and two diodes, to adjust the duty cycle, same thing as pulse width, over most of the range, [0, 100%]. The way this works is, the timing capacitor charges through one diode and one side of the pot, and it discharges through the other diode and the other side of the pot.

From your pictures, I could not read the size of the pot, but I am guessing it is maybe 50 Kohm, or 100 Kohm. I also could not read the size of the timing capacitor, C5.

Also your board has a similar but different output stage, compared to the one seen in that circuits blog. The output stage on your board is 5 MOSFETs, each one a HY1707, all wired in parallel, and switching at the same time.

Also the flyback diode,


is little different too. I think that is what the MBR2650 is there for. It actually has two diodes in it, and I am guessing both are used, placed in parallel with the load, between the high side of the supply, and the drains on those HY1707 MOSFETs, which are alll connected together.

I drew some pictures, circuit diagrams, of what this looks like to me.

These diagrams are just a rough sketch, and a number of details are missing, because I could not really see completely what I was looking at, and what is connected to what.

However, I am hopeful that you will be able to fill in the rest of these details on your own, since you can examine the board closely, and even probe it with a multimeter, or other test equipment.


22 days ago

Hard to reconstruct a ckt without the back side or the voltages needed at the screw terminals.. How much current can it handle.. Is it intended for a three phase motor ?

Jack A Lopeziceng

Reply 22 days ago

I think this gizmo is intended for use with a DC motor, or universal motor, with voltage in the range 10 to 50 volts, and current as high as 40 amperes. That is power throughput as high as 50V*40A = 2000 W = 2 KW!

Or I mean, that is if I can believe the specs found in those eBay and Scamazon listings.




I can sort of see what motivates your guess it might be for a 3-phase motor: since there are 6 of those heat-sinked, transistor looking things.

I was kind of guessing 4 of those might be a H-bridge, but I think that guess is wrong, because the various descriptions suggest the direction of the motor cannot be changed by simply turning the knob.

Maybe it is 6 MOSFETs wired in parallel? Who knows?

Or maybe 5? From the picture attached to this topic, 1 of those 6 looks different from the others, with copper colored back, and the rest silver colored.

Also those 5 look like they have a similar network nearby, consisting of 2 resistors and 1 diode for each. Although I have no clue how that network is wired, but it kind of looks like the same thing, repeated 5 times, once for each of those 5 transistor-looking things.