| 摘要 |
<p>1,031,463. Semi-conductor rectifier switching circuits. JOSEPH LUCAS (INDUSTRIES) Ltd. Nov. 2, 1962 [Nov. 22, 1961], No. 41733/61. Heading H3T. [Also in Division H2] An overload protective arrangement comprises a " gate-controlled switch " 5 and a resistor 7 in series with the load 6 to be protected, the switch 5 being a controlled rectifier having the additional property that the application of a pulse of reverse polarity to that of the triggering pulse switches off the rectifier. The gate of the switch 5 is connected to one terminal 3 of an A.C. supply through a diode 10 and to the other terminal 4 through parallel inductor 9 and resistance means 8. During alternate half-cycles, the switch 5 is non- conductive and energy is stored in the inductor 9. During the intervening half-cycles, the energy in the inductor 9 turns on the switch 5 which conducts. Should the current through the switch 5 exceed a predetermined magnitude, the cathode voltage rises to a value sufficient to turn off the switch 5. The resistance means 8 may be a resistor or a Zener diode. A second similar circuit 5a ... 10a is oppositely connected to obtain current flow through the load and protection on the half-cycles in which the switch 5 is non-conductive.</p> |
