| 摘要 |
<P>PROBLEM TO BE SOLVED: To securely interrupt a control circuit power supply, even if the control circuit power supply becomes unstable at power off operation in the control of load by a control circuit that includes a microcomputer. <P>SOLUTION: When an on/off switch 28 is turned off, the microcomputer 17 turns off an internal switch 32, a transistor 23 is turned off and power supply to the control circuit 16 is stopped. Since the on/off switch 28 is off-operated, the transistor 23 becomes a non-conduction state as it is. Even if the microcomputer 17 malfunctions since power voltage becomes unstable, and the internal switch 32 is turned on, a thyristor 18 is prevented from being turned on. The transistor 23 is thereby prevented from being turned on again. <P>COPYRIGHT: (C)2009,JPO&INPIT |
