Use:
The switches set the overall network voltage tier.
The potentiometer adjusts 0-5volts with a summing amplifier to create a total output voltage.
Description:
I wanted a way to use a cheap DAC to build a linear power supply. This setup would use a cheap DAC to adjust the 0-5v part of the circuit. A microcontroller would switch the various tiers to set the total output for the summing amplifier while the DAC would then be reset to compensate and simply adjust the subsequent 0-5v tier linearly.
I have wanted to experiment with this for awhile but haven't had the chance yet. I'm sure there are more than a few problems with a setup like this.