| 摘要 |
PURPOSE:To manufacture a protective circuit having a simple a structure by fusion-cutting a fuse resistor installed in series with a main circuit by forced short-circuit currents when abnormality is generated and protecting the main circuit. CONSTITUTION:A motor 3 is supplied with a DC power 2 through a semiconductor driver element 1. A fuse resistor 5 is inserted between the semiconductor driver element 1 and the DC power 2, and a short-circuit circuit 8 composed of a resistor 7 and a switching element 6 is mounted in parallel with the semiconductor driver element 1. The temperature of the motor 3 is detected by a thermistor 9: the switching element 6 is turned ON on temperature abnormality, and the short-circuit circuit 8 is short-circuited, thus fusion-cutting the fuse resistor 5 to protect the motor. |
