Electrical power measuring bridge using radiant energy

Claim 1

APPARATUS WHICH COMPRISES: A FIRST BRIDGE CIRCUIT CONTAINING FIRST, SECOND, THIRD AND FOURTH TERMINALS AND FIRST, SECOND THIRD AND FOURTH ARMS CONNECTED RESPECTIVELY BETWEEN SAID FOURTH AND FIRST TERMINALS, SAID FIRST AND SECOND TERMINALS, SAID SECOND AND THIRD TERMINALS, AND SAID THIRD AND FOURTH TERMINALS, SAID FIRST, SECOND AND THIRD ARMS CONTAINING SELECTED RESISTORS, AND SAID FOURTH ARM CONTAINING BOTH A LIGHT SOURCE AND A VARIABLE RESISTOR FOR ADJUSTING THE INTENSITY OF SAID LIGHT SOURCE AND THUS THE BALANCE OF SAID FIRST BRIDGE, A DOUBLE-THROW SWITCH CONNECTED TO SAID SECOND TERMINAL, SAID SWITCH CONTAINING A FIRST AND A SECOND CONTACT, A FIRST NULL METER, CONNECTED BETWEEN SAID FIRST CONTACT OF SAID DOUBLE-THROW SWITCH AND SAID FOURTH TERMINAL, FOR INDICATING WHEN SAID FIRST BRIDGE IS IN BALANCE, A PHOTORESISTIVE ELEMENT RESPONSIVE TO SAID LIGHT SOURCE, AN OPAQUE ENCLOSURE CONTAINING BOTH SAID LIGHT SOURCE AND SAID PHOTORESISTIVE ELEMENT, A SECOND BRIDGE CIRCUIT CONTAINING FIFTH, SIXTH, SEVENTH, AND EIGHT TERMINALS, AND FIFTH, SIXTH, SEVENTH, AND EIGHT ARMS CONNECTED RESPECTIVELY BETWEEN SAID EIGHT AND FIFTH TERMINALS, SAID FIFTH AND SIX TERMINALS, SAID SIXTH AND SEVENTH TERMINALS, AND SAID SEVENTH AND EIGHT TERMINALS, SAID FIFTH ARM CONTAINING SAID PHOTORESISTIVE ELEMENT, SAID SIXTH ARM CONTAINING A VARIABLE RESISTOR FOR BALANCING SAID SECOND BRIDGE, AND SAID SEVENTH AND EIGHT ARMS CONTAINING SELECTED RESISTORS, A SECOND NULL METER, CONNECTED BETWEEN SAID FIFTH AND SEVENTH TERMINALS, FOR INDICATING WHEN SAID SECOND BRIDGE IS BALANCED, A FIRST VOLTAGE SOURCE CONNECTED BETWEEN SAID SIXTH AND EIGHT TERMINALS, A STANDARD VOLTAGE SOURCE, FIRST VARIABLE ATTENUATOR MEANS, CONNECTED WITH SAID STANDARD VOLTAGE SOURCE BETWEEN SAID FIRST AND THIRD TERMINALS, FOR SUBTRACTING FROM SAID LIGHT SOURCE A GIVEN AMOUNT OF POWER DERIVED FROM SAID STANDARD VOLTAGE SOURCE, THEREBY UNBALANCING BOTH SAID FIRST AND SECOND BRIDGES, A SOURCE OF AN UNKNOWN AMOUNT OF POWER FOR INCREASING THE LIGHT OUTPUT OF SAID LIGHT SOURCE BY AN AMOUNT GREATER THAN SAID GIVEN AMOUNT OF POWER SUBSTRACTED BY SAID FIRST ATTENUATOR, SECOND VARIABLE ATTENUATOR MEANS,CONNECTED WITH SAID SOURCE OF AN UNKNOWN AMOUNT OF POWER BETWEEN SAID FOURTH TERMINAL AND SAID SECOND CONTACT OF SAID DOUBLE-THROW SWITCH, FOR REDUCING THE POWER OF REACHING SAID FIRST BRIDGE FROM SAID SOURCE OF AN UNKNOWN AMOUNT OF POWER UNTIL SAID SECOND NULL METER INDICATES SAID SECOND BRIDGE IS BALANCED, AT WHICH TIME THE POWER DISSIPATED BY SAID SECOND VARIABLE ATTENUATOR MEANS EQUALS, IN DECIBELS, SAID UNKNOWN AMOUNT OF POWER.