YCK-7B controller an inside view

[arce]

hello everyone,I've been reading and learning a bunch of stuff from this forum, so finnaly today I decided to register because I'm a bit stumped by this controller I got and I could't find any info on it. As the title says the PCB is market YCK-7B,and it's a generic controller from ebay (I think,because I got it from some guy),on the top label it's marked 48v 800W.
I tested with 4 lead batts and it works fine with my 36V 800W motor that I have on my bike. The only problem is that I want to run it at 36v not 48v but the LVC steps in and stops the controller dead.
Ok now for some facts about the controller:
3x FETS (room for one more) STP80NF75L
2x 20S100
voltage reg LM317
2x 470u 63v CAPS
NE555
LM339
NOW, how do I lower the LVC so I am able to run at 36V or actually it wouldn't be a problem to just disable it altogheter( I use a voltmeter to monitor the batts so there really is no need for a LVC).
I suppose this is an interesting fact: there is no annoying noise coming from the motor even at low RPM, I guess the frequency is above 15KHZ,I'm going to measure this tommorow and see for sure, and let you guys know.

100_1859 (Custom).jpg

(160.07 KiB) Downloaded 3 times

[zombiess]

What motor is this powering, that looks like a brushed controller.

[arce]

oops sorry forgot to mention, yes it's a brushed controller powering a brushed motor from a e-scooter.

[arce]

I solved that little problem with the LVC, if anybody is intersted to know, say so and i'll post a picture with the mod.
Now, I measured the freq. of the output at aprox 26.5Khz. So they went from the annoying 5Khz (or what ever it was) on the YKxx series to this unnecessary high freq.these chinese guys are very strange
I was thinking of lowering it to about 15Khz or even 10khz so to reduce the switching losses quite a bit. I don't know how much efficiency I'll gain from that so any input from the "veterans" out here is welcomed.

And to everyone who chooses to celebrate easter,
HAPPY EASTER!

[zombiess]

Reducing the freq to the minimum needed should get you a pretty big gain in efficiency. Really easy to change since it's a 555 timer.

[arce]

Reducing the freq to the minimum needed should get you a pretty big gain in efficiency. Really easy to change since it's a 555 timer.

Yesterday I was a little bit "under the influence" when i tried to add a pot on the pcb so I could adjust de Freq., well as the story goes I found a schematic on the net for a LM339 based controller and totaly ignoring the fact that my controller uses a 555 timer I added a pot on the numer 2 pin of the LM339 instead of the resistor that was in place.Tested, worked ok I could adjust the freq down to about 7Khz. GREAT!
This morning ,fresh as a daisy,upon further reflection it came to me.... whats the point of the Ne555 timer??? hehe and after reading your post the confusion grew...
YEAH I can read a schematic, use some simple calcs to make adjustements,but I'm very new at this electronics stuff so most of the time I learn as I go...and forums like this are an invaluable resource.
So if you could please imform me as to why some controllers use just the LM339 and some like mine have the extra 555 timer?

PS. the schematic I used was this one http://www.swarthmore.edu/NatSci/echeev ... trolG.html

[Pilotgeek45]

Hey, I have this speed controller and I have a few questions about it. With a higher gearing, my motor has developed a stuttering problem, and I think it's either due to the really high frequency this controller runs at, or it's falsely hitting LVC when it has a large load on it. Could you give a brief description of how to do the LVC mod, and circle in your picture which resistor you swapped out to change the PWM? I just tried changing out the first resistor off pin 2 (the 2k ohm) and while that resistor reduces the frequency, it also greatly reduces my effective throttle range.