| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling overcurrent with the reduced number of components by getting the same elements shared among a driving circuit, a protective dircuit, etc., as much as possible to reduce the cost in an overcurrent protective circuit of a motor. SOLUTION: An FET 3 is installed for rotating/stopping control of a cooling motor 1. The FET 3 is connected to a CPU 2 through a NOT gate 4 and a transistor TR1. A resistor for current detection R3 is installed in a lower stage than the FET 3 and the voltage across the resistor R3 is detected by a comparator CMP 3 and then current is limited. Meanwhile, an overcurrent is detected by a voltage monitoring element 5 and then the detection signal is input into the CPU 2 and thereby a timer is started up. |
