| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent breakdown of a control circuit element, such as IC and LSI or the like due to overcurrent and easily realize recovery, when the over- current protection becomes effective and also easily identify whether latch-up is possible for an overcurrent protecting operation. SOLUTION: A DC power source circuit 11 is fed with a commercial power supply via a power supply switch 12 for feeding an output V1 of the circuit 11 to an IC 16. Three-terminal regulators 19, 20 feed the ICs 17, 18 as the overcurrent monitoring object by lowering voltage V1 to V2 and V3. A voltage monitoring circuit consisting of the inverters 21, 22 and or OR gate 25 monitors an output voltage of regulators 19, 20. If such an output voltage is turned off, the IC 16 turns on a relay driver 15 to shut off the power supply switch 12. Or current sensors 26, 27 and an IC 16 watch an output current of the regulator, and when such output current is 0 due to the shut-off of the output, the IC 16 turns on the relay driver 15 to shut off the power switch 12.</p> |
