Power Supply Trimming Routine

[TonyJ]

Can someone share a power supply trimming loop?  I would like to enter a nominal voltage and have a Upper Limit, Lower Limit as variables and loop until the measured voltage is between the upper and lower limits.  Thanks.

Tony

[James-B]

It sounds like it would be best to write a code module and call it from TestStand.  You could pass parameters from TestStand to the code module that describe the behavior you want.

To help further, it'd be good to know what power supply you are using and how you are talking to it.

[Dennis_Knutson]

There is also the built-in while loop step in TestStand that you can use.

[James-B]

Definitely true, and while it's a matter of preference, for neatness and modularity's sake, I tend to lean on the side of performing related operations inside of code modules.

But yes, if for some reason, you would rather keep everything inside of TestStand or you do not have access to a programming language, you can use the build in while loop.

[crossrulz]

The problem with trimming a power supply is that you really need an outside device to measure the supply output, typically a DMM.  So since we are mixing who different devices, I find it better to just make the trimming loop in TestStand.

But the loops are not hard.

Meas = NaN

Set supply voltage to DesiredV

While(Meas < LL || Meas > UL)

  Set supply voltage (SetV = SetV + (Meas - DesiredV)

  Measure with DMM (set measured voltage to Meas)

End

[Dennis_Knutson]

Of course, if you loop until one of the limits is met, the supplies will not be trimmed to the nominal voltage. It's often better to display the measured voltage until the user clicks an okay button. Then do a numeric test.