Thermostatic transducer for winter and summer operation

Claim 1

IN A THERMOSTATIC TRANSDUCER FOR WINTER AND SUMMER OPERATION, THE COMBINATION COMPRISING A TEMPERATURE-SENSITIVE ELECTRICAL ELEMENT WHOSE IMPEDANCE VARIES ACCORDING TO ITS ENVIRONMENTAL TEMPERATURE, A BRIDGE CIRCUIT HAVING TWO INPUT TERMINALS ADAPTED FOR CONNECTION TO A VOLTAGE SOURCE AND HAVING TWO OUTPUT TERMINALS, SAID BRIDGE CIRCUIT INCLUDING THREE ELECTRICAL IMPEDANCE ELEMENTS AND SAID TEMPERATURE-SENSITIVE ELEMENT CONNECTED IN A BRIDGE CONFIGURATION BETWEEN SAID INPUT AND OUTPUT TERMINALS, A DIFFERENTIAL AMPLIFIER HAVING TWO INPUT LEADS AND TWO OUTPUT LEADS WITH THE INPUT LEADS CONNECTED RESPECTIVELY TO SAID BRIDGE CIRCUIT OUTPUT TERMINALS, AND A SINGLE-POLE, DOUBLE-THROW CHANGEOVER SWITCH HAVING TWO INPUT CONTACTS AND A COMMON OUTPUT CONTACT, SAID INPUT CONTACTS BEING CONNECTED RESPECTIVELY TO SAID OUTPUT LEADS; WHEREBY THE SENSE OF THE PROPORTIONAL CHANGE IN THE SIGNAL AT SAID OUTPUT CONTACT IN RESPONSE TO A CHANGE IN THE SAID ENVIRONMENTAL TEMPERATURE IS IN ONE SENSE OR THE OTHER WHEN SAID CHANGEOVER SWITCH IS RESPECTIVELY THROWN TO ONE OR THE OTHER OF ITS TWO POSITIONS.