At 06:50 PM 01/24/08, you wrote: >I've been searching for a very simple circuit that could turn on a, >maybe, 10 watt resistor at 12 volts, when the temperature drops to >perhaps 30F or so. Anyone have a reliable favorite? > >Laryn K8TVZ
Use a simple heating thermostat, available at Home Depot. Have it key a 12v relay, the contacts handle the load current. The auto junkyards have gobs of 12v relays, available for pennies... grab one designed to run a heater fan ,they have 20amp contacts and 100-200ma coils). Mike WA6ILQ