@cellularmitosis

A circuit board to control automotive headlight relays.

A board for testing a TTL Serial communication channel.

An LTZ1000-based 7V reference (circuit by Andreas)

A board for isolating a TTL serial RX / TX pair using 6N137 (8-pin) optoisolators.

A board for isolating a TTL serial RX / TX pair using 4N35 optoisolators.

A simple adjustable voltage, current limited bench power supply using two LM317 regulators.

A very basic LM399 voltage reference board design.

A small, pluggable 7V LM399 reference module.

An adjustable voltage and current limited lab power supply, implemented with a traditional op amp and pass transistor architecture.