Speed Control Board for Treadmill Motor on a Belt Grinder Build

Thread Starter

jviebrock

Joined Apr 17, 2020
4
Hello, first post here. Hoping you folks can help out an 'electronics-challenged' newb. I picked up a commercial treadmill for cheap that wouldn't run when the incline function was used. I'm interested in using the motor, which is a very nice Leeson, Permanent Magnet DC, 3hp continuous duty motor (130V, 20A) to drive a variable speed belt 2x72-inch belt grinder. Typical AC power requirements for one are less than 2hp continuous duty. My issue is I'd like to ditch the control panel and just utilize the existing speed control board, which is PWM-based and rated at 15A. That board was made by Digital Concepts, Inc. in St. Louis, Missouri and isn't as prevalent as the standard MC-60, MC-2100-type controllers used for residential treadmills. Is there a way to wire in a simple potentiometer to control the speed of the motor using the existing board? Pics of the DCI control board attached.
 

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Mikesfiero

Joined Apr 17, 2020
4
As I mostly do electronic repair, I cannot help you with what you are trying to build. You will need build a PWM generator as you probably know. The only thing you will need to find out is the frequency of PWM that the board requires. You can help me out greatly on a repair I am currently doing. I have a treadmill MCB that I didn't think I was going to use so I robbed a part from it to service another. I neglected to make not of the part specifics or value. As your board is similar, would you be able to send me a pic or post a pic of the ceramic resistor located just above the 6 pin connector in the fourth pic? or just post what it says on it? Your help would be greatly appreciated! Thanks.
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
That does not appear to be one of the MC2100 series that use a 20Hz PWM so it it uncertain what it would take to run it, it it was a MC2100 I could steer you to a solution board.
Max.
 

Thread Starter

jviebrock

Joined Apr 17, 2020
4
As I mostly do electronic repair, I cannot help you with what you are trying to build. You will need build a PWM generator as you probably know. The only thing you will need to find out is the frequency of PWM that the board requires. You can help me out greatly on a repair I am currently doing. I have a treadmill MCB that I didn't think I was going to use so I robbed a part from it to service another. I neglected to make not of the part specifics or value. As your board is similar, would you be able to send me a pic or post a pic of the ceramic resistor located just above the 6 pin connector in the fourth pic? or just post what it says on it? Your help would be greatly appreciated! Thanks.
Unfortunately there isn't a way for me to remove that or the two black plastic pieces next to it to read it. I took the best pic I could after bending them out somewhat. I could sort of make out what looks like a 4.7 micro Q on it. There are two similar items at the other end of board. Pic attached for those, too. Sorry I can't help more, but I'd probably bust it if bent further. I have a call into Digital Concepts in St. Louis and will ask them about that when they call back along with the PWM frequency Max mentioned.
 

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Thread Starter

jviebrock

Joined Apr 17, 2020
4
Unfortunately there isn't a way for me to remove that or the two black plastic pieces next to it to read it. I took the best pic I could after bending them out somewhat. I could sort of make out what looks like a 4.7 micro Q on it. There are two similar items at the other end of board. Pic attached for those, too. Sorry I can't help more, but I'd probably bust it if bent further. I have a call into Digital Concepts in St. Louis and will ask them about that when they call back along with the PWM frequency Max mentioned.
 

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Mikesfiero

Joined Apr 17, 2020
4
Unfortunately there isn't a way for me to remove that or the two black plastic pieces next to it to read it. I took the best pic I could after bending them out somewhat. I could sort of make out what looks like a 4.7 micro Q on it. There are two similar items at the other end of board. Pic attached for those, too. Sorry I can't help more, but I'd probably bust it if bent further. I have a call into Digital Concepts in St. Louis and will ask them about that when they call back along with the PWM frequency Max mentioned.
Thanks for trying. That actually gave me a bit of info. It's great that you are willing to ask Digital Concepts when they contact you back. THANKS!!
 

Giomonte

Joined Jun 26, 2020
43
For those looking for an answer to the original question: How can I run this board without the original treadmill display console.

You'll need a PWM signal generator such as one of these or similar: Google "xy-kpwm". The knob and on/off button are handy. Or you can program an Arduino microcontroller.

This manual shows the pinout of the 8-pin and 6-pin connectors:
https://www.manualslib.com/manual/183952/True-Fitness-350-750.html?page=34#manual

1. Attach the xy-kpwm power and ground to a power and ground pin of the MCU 6-pin connector; then connect the xy-kpwm pwm pin to pin 1 (speed control) of the MCU 8-pin connector.

2. Set the xy-kpwm frequency to between 160-320 (lower end is fine); if doesn't work (unlikely), test other values.

3. Set xy-kpwm on/off button to default OFF on power-on.

4. Switch on MCU and turn xy-kpwm knob to ~10 or more to start motor; keep turning knob to increase speed.

Cheers
 
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