摘要 |
<p>In a multicircuit control apparatus (10) including a mechanical main contact (125) and plural semiconductor switching devices such as triacs (13a, ---, 13d) each connected in series to the main contact, the main contact is closed by a control circuit 15 prior to turning-on of any of the semiconductor switching devices and is also opened by the control circuit 15 after completion of turning-off of all the semiconductor devices.</p> |