Transistor circuit for energizing electroluminescent elements

Claim 1

A CIRCUIT FOR TURNING AN ELECTROLUMINESCENT LAMP OFF AND ON IN RESPONSE TO CHANGES IN MAGNITUDE OF DIRECT CURRENT SWITCHING VOLTAGES FROM A FIRST TO A SECOND VALUE COMPRISING, A TRANSFORMER HAVING PRIMARY AND SECONDARY WINDINGS, MEANS CONNECTING SAID LAMP ACROSS SAID SECONDARY WINDING, A SOURCE OF ALTERNATING CURRENT POTENTIAL OF A FREQUENCY SUITABLE TO ENERGIZE SAID LAMP, A TRANSISTOR HAVING BASE, COLLECTOR, AND EMITTER ELECTRODES, MEANS CONNECTING SAID SOURCE OF ALTERNATING CURRENT POTENTIAL, THE PRIMARY OF SAID TRANSFORMER, AND SAID TRANSISTOR IN SERIES IN THE ORDER NAMED WITH THE EMITTER AND COLLECTOR OF SAID TRANSISTOR RESPECTIVELY CONNECTED TO ONE TERMINAL OF SAID SOURCE OF ALTERNATING CURRENT POTENTIAL AND TO ONE TERMINAL OF SAID PRIMARY WINDING, A SOURCE OF DIRECT CURRENT POTENTIAL CONNECTED TO AN ELECTRODE OF SAID TRANSISTOR FOR BIASING AND TRANSISTOR TO PREVENT RECTIFICATION OF SAID ALTERNATING CURRENT POTENTIAL, MEANS BIASING SAID TRANSISTOR WHICH RENDERS TO TRANSISTOR NON-CONDUCTING DURING APPLICATION TO THE BASE THEREOF OF A DIRECT CURRENT VOLTAGE OF SAID FIRST VALUE, IN WHICH CONDITION THE IMPEDANCE OF SAID TRANSISTOR TO ALTERNATELY CURRENT IS APPRECIABLY HIGHER THAN THE IMPEDANCE OF THE PRIMARY WINDING OF SAID TRANSFORMER AND INSUFFICIENT POTENTIAL IS DEVELOPED ACROSS SAID SECONDARY WINDING TO ENERGIZE SAID LAMP, SAID LAST-MENTIONED BIASING MEANS ALLOWING SAID TRANSISTOR TO CONDUCT TO SATURATION DURING APPLICATION TO THE BASE OF SAID TRANSISTOR OF A DIRECT CURRENT VOLTAGE OF SAID SECOND VALUE, IN WHICH CONDITION THE IMPEDANCE OF SAID TRANSISTOR TO ALTERNATING CURRENT IS APPRECIABLY LOWER THAN THE IMPEDANCE OF SAID PRIMARY WINDING AND AN ALTERANTING CURRENT VOLTAGE SUFFICIENT TO ENERGIZE SAID LAMP IS DEVELOPED ACROSS SAID SECONDARY WINDING.