Light-responsive control system

Claim 1

A CONTROL SYSTEM RESPONSIVE TO A BEAM OF INCIDENT LIGHT POLARIZED IN A PREDETERMINED PLANE COMPRISING MEANS PROVIDING A BEAM OF LIGHT POLARIZED IN SAID PLANE, A WHEATSTONE-DERIVED BRIDGE HAVING FOUR ARMS, EACH ARM OF WHICH INCLUDES A PHOTOCONDUCTOR CHARACTERIZED BY INCREASE OF CONDUCTIVITY IN PROPORTION TO LIGHT IN THE CORRESPONDING PLANE INCIDENT THEREUPON, THE PHOTOCONDUCTORS IN ONE PAIR OF DIAGONALLY OPPOSITE ARMS BEING PROVIDED WITH LIGHT FILTERS POLARIZED IN SAID PLANE AND THE PHOTOCONDUCTORS IN THE OTHER PAIR OF ARMS BEING PROVIDED WITH LIGHT FILTERS POLARIZED IN A PLANE DISPLACED 90* FROM SAID OTHER PLANE, AN IMPEDANCE IN SERIES WITH EACH PHOTOCONDUCTOR, A SOURCE OF INPUT VOLTAGE CONNECTED TO THE BRIDGE, A LOAD TO BE ACTIVATED BY THE OUTPUT OF THE BRIDGE, AND MEANS TO CONNECT SAID LOAD TO THE SOURCE OF VOLTAGE, SAID MEANS TO CONNECT SAID LOAD OUTPUT TERMINALS OF THE BRIDGE, PHOTOCONDUCTIVE MEANS POSITIONED IN SUCH ADJACENCY TO SAID LAMP TO BE ACTIVATED INTO ITS CONDUCTING STATE WHEN THE LAMP IS TURNED ON BY AN OUTPUT SIGNAL FROM THE BRIDGE, SWITCHING MEANS IN CIRCUIT WITH THE PHOTOCONDUCTIVE MEANS, LOAD AND VOLTAGE SOURCE TO CONNECT THE LOAD TO THE SOURCE WHEN THE PHOTOCONDUCTIVE MEANS IS RENDERED CONDUCTIVE, AND LATCHING MEANS IN CIRCUIT WITH THE SWITCHING MEANS TO MAINTAIN THE LOAD CONNECTED TO THE VOLTAGE SOURCE NOTWITHSTANDING EXTINGUISHMENT OF THE LAMP UPON INTERRUPTION IN THE BRIDGE OUTPUT SIGNAL.