I am building a bench power supply from scratch using a Meanwell power supply I’ve got laying around. It’s a 24VDC with 14.6Amp output which is pretty decent for my use. In addition to standard DC power supply function, I want to add some digital capabilities such as controlling CC/CV from computer remotely. I’ve procured 300Watt DC-DC switching regulator which has two 100K trim pots which controls Constant Current and Constant Voltage outputs. Initially I was planning to use 100K Digital Potential resistor to replace the two trim pots, add an Arduino to control them via I2C / SPI and then send commands to Arduino via USB. So far so good…
After some research I realized that the Digi key has a range of digital potentiometers which come in 8-bit (256 steps) and 10 bit (1024 steps). My problem is that even with 1024 steps, I get a voltage resolution of 24/1024 = 23mV which is okay for a hack-job but not even comparable to some of the mid ranged bench power supplies that have an accuracy of 10mV.
I am therefore wondering if there’s a product out there which uses analog potentiometer but with high precision digital control that’ll give me 10mV accuracy?