Making your own Controller

Thread Starter

Bernie D

Joined Feb 1, 2010
Hi all,

I im new to this forum and electronics in a real depth . I must say im pretty impressed with the amount of knowledge on here. I had just posted a thread on taking an electronics course to be able to repair faulty motor control boards in treadmills. Which I think I will do. But I have a new round of questions. I have found a web site which im sure a lot of you have heard of. " ExpressPCB". Looks like they will make any control board for which you send in the schematics on there software. Through my service and from our small retail store we end up throwing away around 30 treadmills a year. Mainly because they cost to much to repair. Is it possible to make a simple motor control board that the speed can be adjusted by a potentiometer ( like some treadmills are ) but will still be of good quality and end up with a quiet running motor? For example, I use the Icon MC70 controller a lot, my thought was to simi copy that board but use only whats needed. Im thinking there is a lot of componets on it that I may not need as I wont have to worry about preset programs being run from the upper console of the treamill. In the end it just looks like I could save huge amounts of money if this idea was to work. With this board I need 115 volts AC in , then with a clean, smooth DC volts out , controlled by the potentiometer. Sounds simple to me, but im sure there's a lot more to it. Thanks for any replies to come.


Joined Nov 28, 2009
Is this the controller you are speaking of?

building the controller will not be so difficult but a few things need to be addressed.

the motor voltage, amps, wattage, horsepower, rpm, whatever info you can gather.

basics in a block diagram or storybook fashion:
not limited to:
you will need to make the power supply to take the mains ac to dc.
you will need to make a PWM circuit for the speed control circuit,
you will need to make a driver board that can handle the current needed..

These circuits will need to be robust enough to handle all the wattage developed.

This will not be as easy and inexpensive as just putting a potentiometer on the motor. Not to mention the " ExpressPCB" cost.

on top of this, what is the liability factor if one of these babies gets whacked out and goes ballistic and hurts or possibly kills someone?

the cost of a motor controller may not be so bad.

There are places that rebuild and sell these controllers.
Why not let them assume the liability?

click on this link. scroll down on his page and see what this guy does for these controllers.

I am not affiliated in any way.


Thread Starter

Bernie D

Joined Feb 1, 2010
Yes that is the mC70 board. Over the years I have seen that board used in .5-2.5 continuous duty HP. I think the motor uses 0-90VDC, Treadmills draw anywhere from 4-9 amps while using them. Some motor controllers have gone ballistic and get run away speed in which they go right to full speed or more ( 12mph) . Customers have never been to upset about that , no real injuries. I thought about just beefing up the part that would cause that. Doing some calculations if I buy 20 boards at a time, it looked to me like I could get them for between $12-$20 each, compared to paying $95(each) from Icon for an MC70.