"Richmond" wrote in message
om...
Currently I am using different timers to control different pieces like
Lights, Duetto CO2 diffuser, Airstone etc.

Is there any (low cost timer) which will switch OFF one and ON another
gadget.
I mean when my light goes off I would like to start my air stone.

Thanks and Regards

Dominic
http://www.dlink.org/aqua

If the informed response is no, a possible solution is to use a timer to
drive the ac coils of a DPDT or SPDT relay. Connect AC+, your lights and
your airpump to the relay contacts (IN, NO and NC positions
respectively). Set your timer to be ON for light ON hours. This will
energize the coil so power goes to the NO position (lights). When your
timer switches off (or there is a power failure), the airpump on the NC
position would normally get energized. This set-up will always alternate
between having the lights OR airpump on (never at the same time).

Go to an industrial supply shop to buy the relay and a relay base with
screw type terminal contacts. Then put the whole thing inside an
electrical box for safety (and to meet elec. code). Your timer should be
on a GFCI circuit as well. Relay and base should not cost you more than
$20. Take the electrical box with you, so you can be sure to buy a size
which fits inside easily.

Due to the variations in wiring code throughout the world, use these
suggestions at your own discretion. Electrical work should only be done
by experienced people. YMMV
NetMax