Control apparatus

Claim 1

IN A TEMPERATURE CONTROL SYSTEM FOR AN AIR CONDITIONING APPARATUS HAVING A FIRST HEAT EXCHANGER FOR HEATING AIR AND A SECOND HEAT EXCHANGER FOR COOLING AIR AND A FAN FOR FORCING AIR IN THERMAL CONTACT WITH SAID FIRST AND SECOND EXCHANGERS TO BE CONDITIONED BEFORE DELIVERY TO THE SPACE, A SPACE THERMOSTAT, A SYSTEM SWITCH HAVING A HEATING POSITION AND A COOLING POSITION, CIRCUIT MEANS INCLUDING SAID SWITCH WHEN IN SAID HEATING POSITION OF CONNECTING SAID THERMOSTAT TO CONTROL THE OPERATION OF SAID FIRST HEAT EXCHANGER, FURTHER CIRCUIT MEANS FINCLUDING SAID SWITCH WHEN IN SAID COOLING POSITION FOR CONNECTING SAID THERMOSTAT TO CONTROL THE OPERATION OF SAID SECOND HEAT EXCHANGER, A FAN CONTROL RELAY, A SOURCE OF POWER, CIRCUIT MEANS INCLUDING SAID FAN RELAY FOR CONNECTING SAID FAN TO SAID SOURCE, SAID FAN CONTROL RELAY HAVING AN ENERGIZATION WINDING AND A TEMPERATURE RESPONSIVE LATCH MEANS RESPONSIVE TO THE TEMPERATURE OF THE AIR LEAVING SAID EXCHANGERS FOR HOLDING SAID RELAY IN A CIRCUIT CLOSED POSITION ONCE SAID RELAY IS ENERGIZED WHEN THE AIR IS ABOVE A PREDETERMINED TERMPERATURE, AND CIRCUIT MEANS FOR CONNECTING SAID ENERGIZATION WINDING TO SAID SOURCE WHEN SAID THERMOSTAT CLOSES TO BRING ABOUT OPERATION OF EITHER OF SAID HEAT EXCHANGERS WHEREBY UPON THE OPERATION OF SAID FIRST EXCHANGER FOR HEATING SAID FAN IS DE-ENERGIZED WHEN THE TEMPERATURE OF THE AIR FROM SAID FIRST HEAT EXCHANGER DROPS BELOW SAID PREDETERMINED VALUE TO KEEP SAID FAN IN OPERATION AFTER SAID FIRST EXCHANGER OPERATION IS TERMINATED; HOWEVER, UPON THE OPERATION OF SAID SECOND HEAT EXCHANGER FOR COOLING SAID FAN IS DE-ENERGIZED SIMULTANEOUSLY WITH THE TERMINATION OF OPERATION OF SAID COOLING EXCHANGER.