Hi everyone.
I'm working on a project that will incorporate a 7 or 8 bit relay array to make a discrete "digital pot".
(7 DPDT relays would make a 7 bit pot)
I know there are commercial digital pots available, but the max voltages (highest rated I've seen was around 50V) rule them out for my application.
Where I need help is in figuring out how to drive this array in a sensible manner. I could of course use 7 or 8 digital outs from a microcontoller, but if I want to have 2, 3 or more of these arrays, I will quickly run out of pins.
Ideally, I would use some sort of "analog to binary" chip, something that would accept an analog signal from the main micro, and have 7 or 8 digital outs for driving an array. If there is such a device, I don't know what it's called, and haven't been able to find it.
I guess otherwise I would need to use a small micro for each array, but that would be non-ideal, requiring multiple micros to be programmed.
Anyway, if anyone has any suggestions, I would greatly appreciate your help!