Sound Voice Activated Relay Switch
This mini-VOX - voice operated relay - is based on a circuit published in Silicon Chip, 9/1994, p31. We have improved it by putting an on-board Koa potentiometer in order to adjust the sensitivity. The idea behind a VOX is that instead of the user pressing a switch to activate a relay, the sound of the users voice itself activates the relay. This gives hands-free control over devices like lights and tape recorders. Relay stays on for 1 or 5 seconds (depending on components used) then shuts off. Different time values can be realized by using different value components (read pdf file for more information).
Sound Voice Activated Relay Switch Reviews: