motor controller from treadmill

B

bubblehead1

Member

• Apr 25, 2021

• #41

One last thing before I go, when I had the motor powered up on the board, I had no voltage at the motor supply terminals and the reason for me thinking the problem was in the board somewhere.

 

MaxHeadRoom78

Well-Known Member

Most Helpful Member

• Apr 25, 2021

• #42

No need to check resistance if it ran OK, It cannot be that much to the controller, it would be based on a similar circuit to the one I posted, maybe a little trouble shooting would point to the problem?

 

B

bubblehead1

Member

• Apr 25, 2021

• #43

Hooked up the two black leads to the motor to my 24v supply and it ran fine. I noticed the rectifier had been replaced at one time or another , it looks like a power transistor also.

 

MaxHeadRoom78

Well-Known Member

Most Helpful Member

• Apr 25, 2021

• #44

I am guessing it is the usual triac used on the input to the bridge. Which is what the TDA1085 uses for motor control.

 

B

bubblehead1

Member

• Apr 26, 2021

• #45

 

B

bubblehead1

Member

• Apr 26, 2021

• #46

The components that were replaced are the two that are mounted to the heatsink. It looks like they would be labeled T1 and B1. Do you think the triac may be bad? How would I test D6, it is different than a normal diode?

 

MaxHeadRoom78

Well-Known Member

Most Helpful Member

• Apr 26, 2021

• #47

D6 is a normal silicone diode.Treat it like any other common version.
The T1 & B1, pretty much indicates Triac & Bridge.

 

B

bubblehead1

Member

• Apr 26, 2021

• #48

So if I removed T1 from the circuit would it test like a transistor? Do you think the bridge might be bad again also?

 

MaxHeadRoom78

Well-Known Member

Most Helpful Member

• Apr 26, 2021

• #49

I usually use a 12vAC source, such as this method.
except use AC and forget S2, then the triac should switch on/off with S1.
The bridge could be tested with the same supply.

 

V

Voltar1

New Member

• Jun 6, 2021

• #50

I have this motor and controller on my metal lathe. Good use for the last 15 years used four controllers in that time.
All failed the same way, unreliable starting and nonexistent speed regulation.
I would like to repair these controllers if possible