Semiconductor time delay switch controlled by variable resistance and having stabilization means

Claim 1

A SWITCHING DEVICE HAVING IN ITS INPUT STAGE: (A) FIRST AND SECOND COMPLEMENTARY TRANSISTORS, EACH HAVING COLLECTOR, EMITTER, AND CONTROL ELECTRODES, SAID EMITTER ELECTRODE OF SAID FIRST TRANSISTOR BEING COUPLED TO SAID CONTROL ELECTRODE OF SAID SECOND TRANSISTOR, (B) A VOLTAGE DIVIDER NETWORK INCLUDING A RESISTOR CONNECTED IN SERIES WITH A PHOTOCONDUCTIVE CELL, SAID RESISTOR INCLUDING A POTENTIOMETER HAVING A TAPER CURVE SUCH THAT THE USEFUL ADJUSTMENT RANGE IS SPREAD OVER A FIRST PORTION OF THE TOTAL RANGE OF SAID POTENTIOMETER, AND THE REMAINING PORTION OF THE TOTAL RANGE CAN BE USED TO EFFECT DE-ENERGIZING CONTROL OF A RELAY BEYOND USED TO EFFECT DE-ENERGIZING CONTROL OF A RELAY BEYOND AND (C) A TIME DELAY NETWORK COUPLING SAID PHOTOCONDUCTIVE CELL TO SAID CONTROL ELECTRODE OF SAID FIRST TRANSISTOR, SAID TIME-DELAY NETWORK INCLUDING A RESISTOR AND A CAPACITOR COUPLED TO SAID CONTROL ELECTORDE OF SAID FIRST TRANSISTOR AND HAVING VALUES SUCH THAT THE RESPONSE OF SAID SWITCHING DEVICE IS SLOWER FOR AN INCREASE IN THE AMOUNT OF RADIATION INCIDENT ON SAID PHOTOCONDUCTIVE CELL THAN FOR A DECREASE IN THE AMOUNT OF RADIATION INCIDEENT THEREON, THE COLLECTOR ELECTRODE OF SAID SECOND TRANSISTOR, THE EMITTER ELECTRODE OF SAID FIRST TRANSISTOR, AND SAID RESISTOR OF SAID