| 摘要 |
<p>1293616 Thyristor circuits RCA CORPORATION 15 May 1970 [19 May 1969] 23668/70 Heading H3T [Also in Division H2] In an A.C. circuit having a thyristor, e.g. a triac, 18 with a firing control circuit 22, 24, 26 and controlling the supply to a load, e.g. an incandescent lamp 10, the triac is protected by a switch 30 which short-circuits the triac when the current through it exceeds a predetermined value. The switch 30 may be a magnetic reed contact unit which is actuated by the magnetic field set up by a radio frequency interference suppression coil 16. Alternatively a thermally actuated switch may be used.</p> |
