A linear CC-CV charger to handle various secondary lithium chemistries. Built with Op Amps and Comparators.

More sensitive to gamma radiation than a Geiger counter with the added bonus of telling exactly what's inside your samples!

Circuit sculpture: a table-top satellite model that shines and measures light (and is environmentally friendly).

Analog robot that uses two light dependent resistors to guide the robot towards a light source, and also reverse if it gets too close

View your mountain bike ride's GPX elevation profile on a PC then play it back on a vintage aircraft altitude indicator!

It simply converts sound into light.

Plugging modules in modified prototype boards allows an affordable and flexible analog computer system with unusual features

Fast Compressor built with minimal components

Op amp circuit for generating Spirograph like curves

A modular mixer where it's easy to add more channel strips.

Active power load for testing of DC power supplies, constant current and constant power modes.

An open-source Analog Lock-In Amplifier LOCKDOWN: LOCK-In Device for Observing Weak and Noisy signals

An FPGA-based video input delay meter using a DVI output chip and an amplified photodiode light sensor

Use op amps to create digital logic gates and higher level logic functions.

Connect phantom-power mics with balanced XLRs to a simple stereo recorder with fixed mixer settings for 3 or 5 channel Decca Tree recording

Portable device to measure low resistance (<1Ohm)

Voltage is set with three BCD switches with a step of 10mV