|
(Click Picture to Enlarge) |
Sound
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
k126.pdf for more information).
Specifications:
- L: 2-1/4" W: 1-1/4" H: 5/8"
- Requires 12 VDC Power Supply
(Need a Power Supply?)
-
Current drain when off is 5-7mA and 35mA
when
activated
- Relay
output rated at 12/24VDC/1A
(more info on
how relays work)
-
Microphone can be
connected on leads up to 2 feet away from
the
PCB.
-
Off time delay adjustable by changing
component values.
See
K126.pdf for complete
details, including schematic and theory of operation. Requires
Adobe Acrobat Reader available at
www.adobe.com
for FREE!
|
