I am building dual adjustable power supply that will double as ( most importantly) a charger for both 1.2 and 12V batteries. The manual adjust at present is 240 sense and 3.3K with paralled switched in 10K pot ( not to easy to adjust to .1V when I was charging 4.8V stack backup battery). I can't decide how to control the regulators. I was considering ls373/R2R at first but it seamed to complicated.
I suppose dac08/opamp is an option which I have around but I started considering PWM if I could achieve small enough (50mV) ripple across the 1.25-~24V range if it was subsequently used for cap or transistor measurements.
Is that achievable?
I just got an 28 pin PIC18f2023 for this but if I use 16f877 I could have 16-18 pins to play with (9 bits per side, still not very elegant).
Thanks Sam.