You're right. I just got up and was a little groggy when I made that statement. I explained it reversed. I realized the mistake on the way to work and I knew someone would catch it. ;-) In some electric baseboard thermostats the put a 62k 1 watt resistor across the load side inside the thermostat to achieve the same. Rick Dave Tweed wrote: > Just to clarify a point that's tangential to this thread... > > "Rick C." wrote: > > Most thermostats are passive. No electronic parts inside. There's usually > > a two circuit mercury bulb that will turn the heat/ac on or off. There's > > also an anticipator resistor circuit that works on the current flowing > > through the heat/ac relay circuit. This keeps the unit from cycling to > > quickly. > > Actually, the anticipator is used to prevent overshoot of the room > temperature by removing the demand for heat before the zone fully reaches > the setpoint temperature. Most heating systems continue to dump a certain > amount of heat into a heating zone even after the demand goes away, and > this is a way of compensating for that. It also can compensate for any lag > between the zone temperature and the temperature of the thermostat itself. > If anything, the heating system will cycle slightly more often, but in > return you get tighter control of the zone temperature. > > On non-electronic thermostats, the anticipator is simply an adjustable > power resistor that locally heats up the temperature sensor whenever > there's demand for heat. There's no corresponding mechanism for cooling. > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu