Standby circuit using a two filament incandescent lamp to maintain approximately thesame light output

Claim 1

THE IMPROVEMENT IN AN INCANDESCENT ELECTRIC LAMP, HEATED TO INCANDESCENCE BY A FLOW OF ELECTRIC CURRENT, HAVING A LIGHT TRANSMITTING ENCLOSURE WITH EXTERIOR SUPPORTING AND ELECTRICAL CONTACTING MEANS AFFIXED ON THE EXTERIOR OF SAID LAMP, THE SAID IMPROVEMENT COMPRISING: TWO SIMILAR FILAMENTS FOR RADIATING LIGHT AND HEAT ENERGY; SUPPORT MEANS FOR SUPPORTING SAID FILAMENTS IN SUBSTANTIALLY PARALLEL PHYSICAL RELATIONSHIP WITHIN SAID ENCLOSURE; MEANS ELECTRICALLY CONNECTING SAID FILAMENTS IN ELECTRICAL PARALLEL RELATIONSHIP; ELECTRICAL RESISTIVE MEANS RESPONSIVE TO THE SAID HEAT ENERGY HAVING A RESISTIVE CHARACTERISTIC APPROXIMATELY PROPORTIONATE TO ITS TEMPERATURE FOR INCREASING THE CURRENT FLOWING IN ONE OF THE SAID TWO FILAMENTS AFTER FAILURE OF THE OTHER; MEANS FOR POSITIONING THE SAID RESISTIVE MEANS WITHIN THE SAID ENCLOSURE IN ADJACENT, PARALLEL, EQUALLY SPACED APART, HEAT RECEIVING RELATIONSHIP TO THE SAID FILAMENTS; MEANS CONNECTING THE SAID ELECTRICAL RESISTIVE MEANS AND THE PARALLEL CONNECTED FILAMENTS IN SERIES; AND ELECTRICAL CONNECTING MEANS CONNECTING THE SAID SERIES CONNECTED PARALLEL FILAMENTS AND RESISTIVE MEANS TO THE SAID ELECTRICAL CONTACTING MEANS.