PWM Solenoid test board adjustment fault

[hydroman247]

I have a PWM solenoid driver test board. Basically a little board which I feed 12v, hook up to a solenoid and a 3 pin pot. I have 2 of these working in conjunction for a bi directional test box I use. Each board has 2 adjustment screws. One if for the minimum bias and the other is the range.

I usually have these set at 500ma min and 800ma max but I need to adjust them occasionally for different applications. Yesterday I was using the box and one board decided it's range was fixed at 120ma. I couldn't lower the min bias and if I raised the range, it would move the min bias with it up and down where ever it went.

My question is, is this board broken completely?

Sorry for using incorrect terms, I am not an EE.

Thanks

 

[hydroman247]

I found a spare board, swapped it and it worked but now the other board in the box is playing up limiting the range adjustment to 10ma????????????????????

Now the replacement board won't work properly either. What is going on?

 

[OperaHouse]

Can you post a clear picture of the board. I'm a believer that form follows function. I haven't been able to follow you so far and a picture would likelt help in figuring out what you are doing.

 

[Skogsgurra]

Not easy to follow you.
The simple answer is: If black and smelly - yes, completely broken. If original colour, then it can be fixed. But otherwise, I agree with OperaHouse.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[hydroman247]

The boards look fine and the power up LED lights up fine. I can describe the boards. They are 3 inches long, 2 inches wide. A few capacitors and other components I do not know the name of. 7 connectors on the board. +V, -V, Solenoid+, Solenoid- and the 3 for the potentiometer.

When power is supplied to the board, the LED lights up and when I turn the pot my solenoid activates but the whole point of these boards is that you can set the current minimum e.g. what the current output is when the pot is at minimum and what the current is at the maximum pot setting. Usually my range is 300ma or more but for some reason, this has dropped to 120ma. I would adjust the range and it would change the min bias as well for some reason.

All 3 boards still work, I can set each to output a certain value BUT not the variation I want.

Does that help? I can't take a picture at the moment. It looks similar to this. Link

 

[Skogsgurra]

Sorry. Your question is a little like a lady (sorry again, but that is usually how it is) phoning the garage and asking if her car can be repaired or not and then describes colour and the funny sounds it emits in certain situations.
I'm afraid we cannot help. You should really either contact the supplier or find someone near you that can have a look and do some measurements.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.