o->|---+ 80V peak (400W) or 28.8V peak (50W) | [ ] R1 | [ ]<-+ RV1 0-10K | | +---+ | +--------------o 2.56VDC | [ ] R2 | V
I have been trying to calc R1 and R2 so I can set RV1 for max attenuation (biggest R) and attenuate 80V to 2.56V. When RV1 is 0 ohms, I'd like 28.8V in to be attenuated to 2.56V. I can puts a legend on the skirt of the knob showing where to set it for 50 (full ccw) 100 200 400 (full cw) watts. I originally was using a fixed attenuator and was going to have the user set a threshold level with a 4 pos dipswitch, but that needed 4 inputs. If I use a tiny85, I can read the one a/d chan and run a pair of red/grn leds. Any other better block diagrams for this topology welcome. Like taking the out from the pot wiper, etc.