I know this is an old thread but I have a similar issue with a slightly different treadmill control board. Its an Aerobics Inc. 9501001 rev f from a pacemaster pro plus treadmill. I do have the upper panel and it works fine, just not ideal for operating a lathe. The upper and lower boards are connected with an rj45 connection with, I believe, 8 fine wires. I would like to simplify the motor control with a simple dial That does not need the speed to be reentered each time the session is paused. unlike others I’ve seen, this control board has no obvious labeling for speed control. One thing I tried was to make up a test set of wires with an rj45 connector, plugging it in instead of the connection from the upper panel. One wire indicates 5 volts when tested to any of the other wires. One tests as ground.
4 of the wires will elicit clicking sounds from the control board if i connect them with a double a battery. On one occasion the motor started when 2 of the wires had the double a battery connection, but I couldn’t get that response again. Everything still works fine it I reconnect it to the upper controls. I can solder ok but am not well versed in electronics. Appreciate any insights anyone can provide.

Moderator edit: New thread created from this.

 

I made a new cable with rj45 connectors and am using it to test voltage. When running, 3 of the cables have voltage readings one is 4.9 volts one is 4.4 volts and one is 2 volts. I have a fluke 88 automotive multi meter which has a pulse function bit I had no luck getting a reading. The detected voltage did not vary with the speed of the motor. I am hoping someone can help me figure this out as I am a bit over my head in this…

on a lark i ordered an inexpensive pulse generator hoping that it can replace the upper treadmill circuits.

 

4 wires with voltage readings

https://docs.google.com/spreadsheets/d/1-Ia86nG-VPR6f_jfFd57jiUEDciojZct9yGQ5d3qkS0/edit

the readings with the motor running do not appear to change at different rpms. My previous post indicated only 3 wires with voltage readings, actually there are 4….

 

Well, made some mistakes but inching closer to my answer. Retested everything and did discover one wire, listed as 1 (one) in my previous post does in fact have the voltage vary up and down with motor rpms the range seems to be around 1 to 5 volts. Wire 2 is around 5 volts pretty much steady. Wire 3 seems to be at 4.4 volts when the motor is running and 0 when the motor is not running. Wire 4 appears to be a ground so not sure why that shows 2 volts motor running and 4.2 with the motor stopped. As I said, I do not have any electronics background.

 

Still barking up the wrong tree. I assumed red and black were the primary dc +- this appears to be incorrect. I now believe them to be the speed sensor wires. I bought an inexpensive pwm signal generator and it would not light up with red and black. It does light up with white and blue, but still have not got the motor to go. I assumed the green wire which when powered and controlled by the treadmill boards alone varies in voltage between 1 and 5 volts depending on the motor rpms to be the wire to connect to the pwm terminal on the small pwm device. I am unsure of how to determine the frequency to set the device to. It seems that many posts for some different boards say 20 hz which I tried with no luck.

 

Some more data that I don't know how to interpret. With the motor running, the green wire’s voltage varies from 1 to 5 volts dependent on motor rpms. It appears to test at a steady 488 hz.

The red wire‘s voltage is steady at around 2 volts but it’s frequency varies with the rpms of the motor.

i tried the green wire in the pwm port on the tiny pwm device and set the frequency to 488 hz with no luck. Also tried it at 20 hz as so many recommend. No luck. I’m wondering if the problem has something to do with the magnetic switch in the upper board. Just seems like I need to activate a relay or something in the power supply board for it to work. I‘m testing with the existing control boards connected with the original cable that I have exposed some wire on for testing.

 

Ok, I can run the motor with the existing circuit boards connected with 5 of the 8 wires. Blue wire is ground, clear wire is 5vdc + , green wire voltage varies 1 to 5 volts depending on rpms of the motor and reads 488hz. Red wire reads 4 volts not running but 2 volts running and hz varies with motor rpms. the black wires role is unclear to me but when I tried to disconnect it when running it caused the circuit board to click like a relay sound and stopped.

I would really appreciate it if anyone can help me make sense of this. I have a 4 terminal pwm generator that I have tried in various configurations with no luck.

Thanks, paul

 

Finally a bit of success! It seems the pwm generator route was perhaps not the correct approach.

I decided to try a potentiometer instead. The clear (looks white in the pic) which is the 5v+ on pin 1, the green on pin 2 and blue ground on pin 3. The black wire needs to connect to pin 1 for it to run. I will install a toggle switch between pin 1 and the black wire. This , I think, replaces the magnetic safety switch on the treadmill.

It works!

I will post another pic when I get the wiring cleaned up a bit.

 

Forget the last post, I was wrong again. Potentiometer did get the motor to run but not well. Thinking I was done I pulled the upper circuit board out and noticed it was labled as a pwm controller. That led me back to trying to figure out the tiny pwm device. I wired it as follows blue dc - , clear and black on dc+ I ran a new wire to grnd , and green on pwm. I set the device to 488 hz . It works, correctly I think.

powering the black wire was the missing piece of the puzzle. This is the equivalent of using the small magnet on the upper board.


spindle speed adjustable between 300 rpms and 1600 rpms