ELECTRO is a battery-powered supply for testing analog chips. Two 18650 lithium-ion cells provide an isolated power source, reducing the supply noise that can interfere with measurements.
An ATmega32U4 microcontroller monitors cell voltage and temperature. The control system includes passive cell balancing and over-current protection. The output ranges from 5 V to 8.4 V.
Measured ripple was 3.89 mV peak to peak. The prototype cost about $80 to build. The poster above describes the measurements and comparisons with commercial bench supplies.
