Hacking Treadmill Control Board

Thread Starter

CyberBoy

Joined Oct 4, 2020
3
Hi I am new and have joined the forum with a specific question. I have a treadmill control board model number BC-1075(2) Made in Taiwan. I have its motor too. I wish to use the controller and motor to power my lathe. I dont want to use the big treadmill display panel, instead I want to use a potentiometer to control the speed.
The board has 2 AC input and 2 motor output connections and a socket with wires that ran to the treadmill diaplay panel. The socket has 7 wires , namely

1. GND
2. +12V
3. FAST
4. SLOW
5. GND
6. GND
7. S/W

Can someone guide me where to connect the potentiometer for speed control.

Pictures attached. Thanks in advanve.

Best,
 

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MisterBill2

Joined Jan 23, 2018
18,176
If you still have that control panel and the connecting cable then there is a chance of using a meter to discover how to do it. If not, you are out of luck for an easy solution..
The process would be to connect all the parts and record the voltages on the connector as the controls are operated.
The speed setting adjustment is that small blue device towards the bottom marked speed. You could replace it with a remotely connected potentiometer of similar resistance. But if you do not have excellent soldering skills do not even think about trying that. The destruction of the circuit board would not be repairable.
 

Thread Starter

CyberBoy

Joined Oct 4, 2020
3
Hi

I dont have the control panel but I have excellent soldering skills. There are 2 mini blue devices one is for speed and the other is for torque . Translating to electrical language the speed control is voltage and torque control is current.

I still have hope, can someone provide the datasheet of this board, of they have as google search has resulted in no results.

Here is a shot (not very clear sorry) of the connector to control panel. See if it can give some idea...

Best,
 

Attachments

MaxHeadRoom

Joined Jul 18, 2013
28,619
Although I am not familiar with that particular controller, I suspect it may be be using the now more popular method of PWM signal to control the RPM, similar to the more popular MC2100 boards etc.
These boards have fortunately been reverse engineered to some extent.
Max.
 

MisterBill2

Joined Jan 23, 2018
18,176
On that connector I see fast and slow , +12 and Gnd. and one terminal marked S/W and possibly something additional. So one option is to connect the motor and power the board and see if anything happens. If nothing, Then the next step would be to connect a pot between the +12 terminal and the Gnd terminal and apply some intermediate voltage to the fast or slow terminals.
Another good choice is to examine and trace out the connections to those terminals and see if they go to inputs that are digital or that seem more analog. That would give a hint about what to try.
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
even if the control to the motor is PWM, the input to the controller will probably be analog. PWM seldom begins at the input.
Seldom??
One of the most popular T.M. controllers is the MC2100 and there is no analogue used, it is all by PWM directly into the micro.
The speed monitor is fed up to the console where is compared to the digital programmed rate and the PWM control is adjusted accordingly.
Max.
 
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MisterBill2

Joined Jan 23, 2018
18,176
And why not?
It works quite well, why bring analogue into it if you don't have to?
What do you have against it?
Analog controls have finer resolution and do not require a processor to create the signal. And they do not require a processor and program code. And mostly I can have an analog circuit with all of the parts available from many manufacturers. That means that loss of one source does not stop the production line. That can be important sometimes. And my analog designs can be repaired with new parts even though the original was built 25 or 30 years ago.
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
The earlier versions are Pot controlled analogue, but these have been replaced by the PWM versions, they control the RPM very precisely which is essential for T.M. applications.
I sense in many of your posts, you have something against Digital/micro processor control.!?
I work principally in CNC systems where although I use analogue/trans-conductance servo amps, the trajectory is under control of a very high speed processor, with digital encoder feedback in the order of 18 mhz.
And just about every CNC system I have come across does it a similar way, including digital servo amps.
A cannot visualize a 8 axis interpolated CNC machine without a microprocessor!.
Even your HVAC ECM motor has a micro on board.!
You cannot fight progress!
Max.
 
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MisterBill2

Joined Jan 23, 2018
18,176
A cnc machine is a precision device and certainly quite an expensive one, with a whole lot of capability, and there is a demand for all of them being the same. Hobby electronic projects very seldom have any of those demands, and certainly do not justify the expenses associated with processor digital control. There is a time and a place for processor controls and it is not everywhere. The real world is analog, keep that in mind. And using a processor will not teach very much about how circuits work, will it? And how can you make a small adjustment on some control scheme when it needs to be edited and then downloaded instead of turning the knob on a pot just a bit?

In this particular instance I hope that the TS is able to trace those pins back in far enough to see that either they are digital inputs or analog inputs.
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
How ironic!
Quote:
Nuts and Volts is a bimonthly American magazine for the hands-on hobbyist, design engineer, technician, and experimenter. It has been published by T&L Publications since 1980 and leans heavily toward microcontroller and digital electronics projects. The magazine is based in Corona, California.
 

MisterBill2

Joined Jan 23, 2018
18,176
How ironic!
Quote:
Nuts and Volts is a bimonthly American magazine for the hands-on hobbyist, design engineer, technician, and experimenter. It has been published by T&L Publications since 1980 and leans heavily toward microcontroller and digital electronics projects. The magazine is based in Corona, California.
Their projects seem to ALWAYS use an arduino board even when a simple comparator could provide the identical function. And NEVER any discussion of how the I/Oworks, just about what boards to buy.
 
CyberBoy did you ever get an answer to your question about the treadmill motor controller? I found your post because I had an identical problem, with a control board that sounds much like yours. A Free Spirit treadmill T325/335/30520/30521-110V, made in 2005. The control board is labelled 900176/75(2) KING.
I had found the motor, controller and frame - but minus the display board.

So with a little preliminary experimentation I found the following:
1. Connect pins SW with VCC starts the motor at a very low speed. I suspect the SW is the key switch found on the display board. A light duty switch was used to achieve the same thing.
2. A pulse of GND to FAST or SLOW sets the new motor speed. It requires repeated contacts to raise or lower the speed. Continuous connection will not do it.
3. Removing the SW to VCC connection stops the motor and requires resetting the motor speed with point 2.
4. Alternately simply removing one of the motor wires (red or black) stops the motor quickly. Reconnecting restarts the motor at the last set speed. A simple switch would accomplish this.
5. The tiny trim potentiometer labelled SPEED can be set lower to prevent the motor from starting to run when point 1 is activated. This however does limit the maximum speed the motor can reach by point 2. But since the top speed is about 4000 rpm, this should not be a problem.
6. If your board controls an incline motor - connecting VCC to INC-U or INC-D will cause the incline motor to run. It is a 115 V AC motor operated by relays on the main control board.

The incline motor will turn for 36 turns until the internal limit switches stop it at either max up or max down. The small wires are from an internal potentiometer which would have told the display board the incline angle. Not needed for most other uses.

I'd appreciate any further discoveries on this particular motor and controller.
 
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