Introduction - If you have any usage issues, please Google them yourself
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 k126.pdf for more
information).