Controlling a Power Supply with a potentiometer through labview

[JBerry25]

Hi,

I have a power supply that can only be controlled externally through a potentiometer.  I am attempting to control this power supply and be able to vary its setting through a LabVIEW interface.  I am wondering what the best method to control a digital potentiometer that I can hook up to the BNC port on the back of the equipment is.  I have access to arduino if that would be a good way to control it, and also have a DAQ BNC array which I am planning to use to control other pieces of equipment.  Otherwise, if there is a way to more directly control the pot. through LabVIEW that would be great too.

Thanks for the help,

J

[crossrulz]

What potentiometer are you using?  How is it controlled?

[JBerry25]

I haven't ordered it yet but I was considering using this 10K d-pot (https://www.sparkfun.com/products/10613).  I have access to plenty of breadboards that I can use, which I could then possibly hook up to my BNC-2090 terminal block.

[crossrulz]

That chip is controlled by a SPI bus.  If your Arduino has a SPI interface, go with that.  Otherwise you could get a USB-8451.

Another idea is to find a UART-SPI controller and then you just need a serial port on your PC.  I have experimented with a UART-I2C chip with success.

[Henrik_Volkers]

Most (low voltage) power supplies with voltage setpoint potentiometer use that potentiometer to create a reference voltage that is compared to the output with in a control loop, or simply divide the output voltage with that pot to compare it with a internal ref voltage again feeding the control loop.

Usually it's no problem to modify it to a control voltage input. BUT high voltage and real floating supplies need an extra look!

A schematic of the power supply is of great help 🙂