No Image

Sound-Controlled Relay

April 21, 2011 Rend 0

This is a relay circuit that detect the presence of sound to activate the relay. You can use this sound-controlled relay as voice operated switch, […]

No Image

Optical Theremin

April 17, 2011 Rend 0

Normally, Theremin works by detecting hand proximity using capacitive coupling method. A Theremin circuit shown in the schematic diagram below use different method to control […]

No Image

Simple Digital Theremin

April 11, 2011 Rend 0

Theremin circuit shown in this schematic diagram uses digital component, so we can call it a digital Theremin. This circuit employs  logic inverter 74C04 or […]

No Image

Single Chip Theremin Circuit

April 7, 2011 Rend 0

This schematic diagram show a single chip Theremin circuit.  Theremin is an electronic music instrument which sense hand movement to control the tones/frequency.  This Theremin […]