Title:
OVERCURRENT PROTECTIVE CONTROLLER
Document Type and Number:
Japanese Patent JP3537317
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an overcurrent protective controller, which can surely avoid an overcurrent not only when a failure in a control object such as motor locking, etc., occurs but also, when a failure in the controller such as a runaway occurs.
SOLUTION: An overcurrent detction unit 103, which detects an overcurrent outputs an overcurrent signal to a latch unit 106 which output holds the overcurrent signal with respect to a control unit 105 and holds it and reverses and cuts off the output of the motor control signal of the control unit 105. With the cut-off, the drive of a power transistor 102 is discontinued and a current supplied to a motor 101 cut off surely. If the control unit 105 operates normally, a power supply 104 stops supplying a power, in accordance with the output of a power supply off signal, and the power supply cut-off is confirmed by a voltage detection unit 107 which outputs a latch release signal to the latching unit 106. If the control unit 105 is not operating normally, the power-supply off signal is not normally outputted, and the power supply 104 does not stop supplying the power. Therefore, the voltage detection unit 107 is not able to confirm the power supply cut-off and hence the latching will not be released.
Inventors:
Tani, Yuji
Maeda, Shiro
Fukui, Seiji
Uejima, Takahito
Maeda, Shiro
Fukui, Seiji
Uejima, Takahito
Application Number:
JP18771198A
Publication Date:
June 14, 2004
Filing Date:
July 02, 1998
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
H02H3/08; H02H7/00; H02H7/08; (IPC1-7): H02H3/08; H02H7/00; H02H7/08