| 摘要 |
<p>1,117,435. Control of A.C. motors. COMPAGNIE GENERALE D'ELECTRICITE. 27 June, 1966 [28 June, 1965], No. 28789/66. Heading H2J. In a three-phase motor control system, arcing in reversing contactors (6, 7) is prevented by supplying the motor via semiconductor devices (1, 2, 3) which are arranged to be non-conducting when the contactors are operated. The devices are of a type which conduct in both directions so long as a voltage is applied to a control electrode. This voltage is full wave rectified A.C. from separate secondaries of a transformer (4), the primary of which is energized from a further transformer (5) via direction controlling push buttons (8, 9) and interlock contacts (63, 73) on the reversing contactors and, when appropriate, limit switches (14, 17). The motor is energized only while a push button is held on.</p> |
