Automatic substitution of a standby power source rendered operative only when the lamps are connected

Claim 1

AN EMERGENCY INSTALLATION FOR USE IN CONJUNCTION WITH THE MAINS OF A POWER PLANT TO SUPPLY TO AN APPLIANCE IN THE EVENT OF POWER FAILURE OF THE PLANT COMPRISING A STORAGE BATTERY SOURCE OF EMERGENCY POWER, A CHARGING CIRCUIT FOR SAID SOURCE CONNECTED TO SAID MAINS, A HIGH FREQUENCY CONVERTER CONNECTED TO SAID SOURCE OF EMERGENCY POWER FOR SUPPLYING HIGH FREQUENCY THEREFROM TO SAID APPLIANCE ONLY IN THE EVENT OF POWER FAILURE, A PRIMING DEVICE INTERCONNECTED WITH SAID CONVERTURE TO HIGH FREQUENCY SUPPLYING CONDITION TO THE APPLIANCE ONLY IN THE EVENT THAT THE LATTER IS IN OPERATIVE CONDITION AT THE TIME OF POWER FAILURE TO MAINTAIN THE OPERATIVE CONDITION OF SAID APPLIANCE FROM SAID BATTERY SOURCE OF EMERGENCY POWER, SAID CONVERTER INCLUDING A FLIP-FLOP OSCILLATING CIRCUIT THAT IS NORMALLY BLOCKED BY A REVERSE POLARIZING VOLTAGE, SAID PRIMING DEVICE SERVING TO ACTIVATE SAID CONVERTER OSCILLATING CIRCUIT BY A SECOND POLARIZING VOLTAGE, AND SAID APPLIANCE INCLUDING A CIRCUIT HAVING TAPS, AND A RECTIFIER IN SAID PRIMING DEVICE CONNECTED TO SAID TAPS TO PROVIDE SAID LAST-NAMED POLARIZING VOLTAGE.