Then I came across Terrys_Dual_555_MC_2100_Driver_Circuit.pdf and on page 4 found the answer. I put a 330 ohm resistor in line with the pulse signal to the MC2100 and it fired right up. I have very accurate control from about 6% up to around 85% duty cycle. If you are above 0% duty cycle when you start the controller you have to go back to 0% and then forward before the motor and led respond. The easy workaround on this is a momentary button that interrupts power to the PWM module while you turn the board on. Then when you release the button the controller will ramp to the preset speed on the PWM module.
It appears some people are getting this to work without the resistor which would create the confusion of them actually working or not. At any rate, if you’re going down this path and not having any luck, read his article and try a resistor.

Did you read my post in #71?
I mentioned that it requires an added series resistor.
The PWM pic based 20hz controller I developed, with two P.B. - Stop-Start functions will stop and re-start from zero RPM and ramp up to what ever the pot is previously set to.
Control is from 0rpm to motor rated RPM.
.

 

Did you read my post in #71?
I mentioned that it requires an added series resistor.
The PWM pic based 20hz controller I developed, with two P.B. - Stop-Start functions will stop and re-start from zero RPM and ramp up to what ever the pot is previously set to.
Control is from 0rpm to motor rated RPM.
.

I did remember that post, unfortunately at the time I thought it only was needed with your pic based controller, I didn't get that it might be necessary with this PWM amazon controller. When I read the article the first thing popped into my mind was what you said back then. Wasn't paying attention enough was I...

 

I thought it fairly explicit !

"The input is into an Opto isolator, but the input resister is very low, 22Ω and usually requires a resistor in series, dependent on the voltage used."

 

I thought it fairly explicit !

"The input is into an Opto isolator, but the input resister is very low, 22Ω and usually requires a resistor in series, dependent on the voltage used."

In hindsight, that was very specific. At the time I was working with a board I didn't know much about nor what was wrong with it. No matter what I did with PWM, it wasn't going to work. But yes, you were spot on! Once the board was working that is exactly what it needed.

 

Hi. Been following the various threads on here related to what seems to be a common failing circuit board! I have the pro form pro 1000, with the mc2100-els-18w-zy controller. Had the same symptoms...powers up fine, incline fine, soon as motor started get a little surge and it trips the fuse or the circuit breaker. Tested the motor using a drill battery, and works fine. Also got a second motor, that works fine too from the drill but not when connected up. Checked advice here and replaced the various components against the heat sink, with the usual suspect mosfet showing some heat on the insulation tape. I had various disasters (I'm a dabbler, but not an expert) but now am at the point where it all seemingly works, the controller comes on but when you hit power the belt doesn't move. It doesn't trip anything and the timer runs as if the treadmill is on (and the led on the board shows a regular fairly fast blink until you hit stop). But no movement of belt/motor. Tried the second motor and same symptoms. Any ideas?

 

As I think i have mentioned before, the best way to trouble shoot these boards is with the main board removed together with the motor, and tested on the bench using a suitable variable PWM 20hz signal into pin 4 of HD2.
The LED should be a fairly slow - steady period flash, if rapid, this indicates a fault.

 

As I think i have mentioned before, the best way to trouble shoot these boards is with the main board removed together with the motor, and tested on the bench using a suitable variable PWM 20hz signal into pin 4 of HD2.
The LED should be a fairly slow - steady period flash, if rapid, this indicates a fault.

Thanks. I don't have anything to test like that. Having checked the diagnostic patterns of the LEDs it seems to just be a slow pulse, and only comes on when pressing the speed button, and stops then when hitting the stop button. Does the speed sensor need to be connected for it to work?

 

No, you do not need the speed sensor., but only when ran separately, if the console is connected then I am not sure whet the result will be.
If it is a slow steady flash then that means the processor is receiving the PWM.

 

No, you do not need the speed sensor., but only when ran separately, if the console is connected then I am not sure whet the result will be.
If it is a slow steady flash then that means the processor is receiving the PWM.

Not sure to be honest. Went back to it today and it's the same old issue...all good, surge on motor start, fuse trip. Think I've trouble shooted to all my capabilities and so a new board...I'm assuming that there isn't an issue with the motor or incline that can ruin a new board?

 

You can test the motor to some degree by using an automotive battery to run it on the bench e.g.

 

You can test the motor to some degree by using an automotive battery to run it on the bench e.g.

Incline motor works no issues. And treadmill motor runs OK on a battery. So assume its all controller issue

 

Not trying to beat this thread to death but it's chocked full of great info! I also find myself in the camp of having an MC-2100 Rev b that would spin up the motor almost to full blast only to die roughly 1 second later.
With the help of this thread I determined the IRFP250N was indeed dead (shorting between pin 2 and the others)

So today I replaced with the only alternative I have.. an IRFP260. Since then the controller "acts" normal. When loaded with the motor the status LED blinks normally. Unloaded the DC outputs are reading a bit over 150VDC regardless of PWM duty cycle, which I believe is normal yes?.
However back to when it's loaded, I'm reading zero voltage out.

Now I'm also using on Amazon sourced XY-KPWM generator, it's getting it's 12vdc from pins 1 and 2 on HD2. With the PWN side grounding on pin 6 and feeding the square signal to pin 4.

I did not, however, know that the PWN signal should be resisted. So I've been testing on and off for over two weeks w/o a resistor. Due to todays symptoms I'm wondering if I could have damaged this 'opto' component the Mosfet drives?

The motor leads ohm to 0.7, and voltage output on the PWM lead varies from .0045 on 0% duty cycle to over 6vdc at 80%+. The oem diagram states that dig MM's should not be able to read this accurately and will show ~1.5... so the reading of 6vdc is concerning.

 

. Unloaded the DC outputs are reading a bit over 150VDC regardless of PWM duty cycle, which I believe is normal yes?.
I did not, however, know that the PWN signal should be resisted. So I've been testing on and off for over two weeks w/o a resistor. Due to todays symptoms I'm wondering if I could have damaged this 'opto' component the Mosfet drives?
With the PWN side grounding on pin 6 and feeding the square signal to pin 4.

The DC level will always be high, it is the pulse width that matters.
You should use the appropriate series resistor with the opto, it could have stressed it using just the in-place 22Ω !
Pin 6 of HD2 is the incline motor control!
Unless you mean HD2 P8?

 

Yeah after I read your post #71 (or 72) I did find and throw a 330ohm resistor into the fray. I'm not 100% positive but it sounded as though a resistor goes between the pwm generator and pin 4, yeah?

And I probably counted pins from the wrong end, either way HD2 has grounds at both ends and Im using them both.

 

The external resistor goes in series with the low value one in circuit to the opto input.

 

I'm sorry I feel like such an idiot here. Or I missed a circuit diagram other than the one found inside the original TM.

 

I presume you have the reverse-engineered schematic shown in post #10 ?
https://forum.allaboutcircuits.com/...-controller-for-treadmill.102804/#post-776250

 

Ah no I must've missed this. So appears that pin 4 on hd2 does indeed hit a resistor prior to U1. Damn that's a sweet diagram.. good job on creating that.

 

So R2 is good, reading 22.2ohms. I tried checking the diode in U1 and reading between pin1 anode and pin 2 cathode, I get nothing. Could U1 be bad even though the status LED flashes when its all hooked up and receiving a PWM signal?

 

Yed, If LED flashes then this indicates that the CPU is receiving a command signal.