Abstract: A thermostat uses a source of a signal representing anticipation heat which is transmitted to a circuit to be combined with a signal from a temperature sensing element with a first time constant or delay when the thermostat is "ON", i.e., controlling a heat source to supply heat to a heat receiver and with a different time constant or delay when the thermostat is "OFF", i.e., controlling the heat source to interrupt the supply of heat to the heat receiver.

Abstract: A shorting and test mechanism for an electrostatic air cleaner uses an electrically conductive spring element attached to an access door to the air cleaner whereby an opening movement of the door effects a motion of the spring to contact the high voltage electrode support assembly to discharge any residual electrical charge on the high voltage assembly to ground. Conversely, the closing of the access door forces the spring away from the high voltage electrode assembly to permit a normal operation of the air cleaner. The spring is further connected to an electrically insulating test button located in an opening in the access door to induce by an operator a selective motion of the spring toward the high voltage electrode assembly whereby to test for the existence of the high voltage on the electrode assembly by providing an electrical arc path to ground through the spring when the test button is depressed.