| 摘要 |
PROBLEM TO BE SOLVED: To provide a relay circuit in which continuous flowing of an overcurrent to a load is prevented. SOLUTION: In the case of limiting a load current, since MOSFETs 3a, 3b reach a high impedance state, a voltage generated between output terminals O1, O2 is increased. A current is supplied to Zener diodes 8a, 8b by the voltage generated between the output terminals O1 and O2, either of over-current display LEDs 10a, 10b is lighted to indicate the overcurrent flowing. In this case, since photo transistors(TRs) 9a, 9b receive an optical signal from a light emitting element 1, the current flowing is made available. On the other hand, when no input signal is given to the light emitting element 1 and the photo TRs 9a, 9b receive no optical signal from the light emitting element 1, no current flowing is made and it is a shut-off state for the relay circuit. |
