Being an electronics hobbyist, I'm having quite a challenge to design a PSU, which must run both on batteries (during the night time) as well as on Solar energy (daytime). The device is intend to run 3x brushless motors daily, while in night-time it should keep the telemetry alive.
What I'm particularly worried about the design:
- a) Is there anything I could improve about the common-ground design?
The logic-level transistors sit on the low-side, while I must monitor
voltage levels of both - the battery and the Solar array
simultaneously. My common ground solution looks like a poor-mans
approach, since voltage drop in the circuit is significant even with Schotkys.
- b) what's the best method of sucking all the current out of Solar
cells, while prioritizing the 3V & 5V devices over the motors &
charger? The transistors introduce huge energy waste due to heat
while in ohmic region.
The components chosen:
- transistors: IRLZ44N and MTP3055VL
- for gate controll I've chosen a digital potentiometer: MCP4261
- uC: Atmega328P
- voltage sensing via MUX: CD4067BE
- current sensing via HALL: ACS712