Abstract: A heater having selective power rating includes a source of electric current, at least one heating unit and at least one electric conductor having an input and an output. Each conductor is permanently fixed at its input and its output so that the conductor is in electric communication with the source. Each conductor is in one of two states. In a conducting state, the conductor is electrically continuous between its input and its output. In a nonconducting state, the conductor is severed between its input and its output. A first conductor is disposed with respect to the source and a first heating unit so that the first heating unit operates at a power level that is dependent on the state of the first conductor. The source and the at least one heating unit are configured to produce one of a plurality of a desired power levels depending on the state of the first conductor.

Abstract: A wireless air conditioning control system is provided. A thermostat assembly measures ambient temperature in an area to which an air conditioning system provides conditioned air. It compares the measured ambient temperature with a predetermined target temperature and wirelessly transmits air conditioning request signals to an air conditioning control assembly responsively to the comparison. The thermostat assembly and the air conditioning control assembly may be automatically mated with one another so that the air conditioning control assembly responds to air conditioning request signals only from a particular thermostat assembly. Where a plurality of transmitters are present, their transmissions are staggered to avoid data collision. The control assembly includes a freeze protection mechanism to protect against freezing conditions in the absence of air conditioning request signals. A battery powered thermostat assembly is intermittently partially shut down to reduce power consumption.