I am a Electrical Engineering student working on a senior design project. One of the features of project is to control the bias current going into the power tubes of a vacuum tube amplifier. Our range of control needs to go from 30 mA to about 137 mA. The voltage across the digi pot should be around 5.5V. Do you know of any digital pots capable of handling this kind of current? A 100k resistor would work but a 1Meg resistor would be a dream come true.
If you don't know of any digipots capable of handling that do you have any other ideas as to how to digitally control the bias current with an Arduino Zero?