Title:
OVERCURRENT PROTECTIVE DEVICE FOR SEMICONDUCTOR DEVICE
Document Type and Number:
Japanese Patent JP3500852
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To attain a compact and economical protective device using an optimum protection logic and a minimum number of measurement means by stopping the operation of a semiconductor device by means of the output of the first or second overcurrent detective means.
SOLUTION: This device is provided with a comparison circuit 2 for allowable instantaneous current Ia set by a setting circuit 1 and the current flowing through a semiconductor device, and a comparison circuit 7 for the output of an integrating circuit 4 and the current set to a setting circuit 6. The comparison circuit 2 sends a signal to a device stopping command circuit 9 through an OR-circuit 8 to stop the device if the detected current is in excess of the allowable instantaneous current Ia. An calculating circuit 3 calculates a constant K1 by inputting the detected power and the integrating circuit 4 counts? to output a signal. A reset circuit 5 gives a reset signal to the integrating circuit 4 for each fixed period and resets an integral value for additional integral calculation. When the output exceeds K1, the comparison circuit 7 sends a stopping signal to the device stopping command circuit 9 through the OR-circuit 8. It is thus possible to attain a compact and economical protective device.
Inventors:
Yasushi Matsumura
Joji Kawai
Joji Kawai
Application Number:
JP11903096A
Publication Date:
February 23, 2004
Filing Date:
May 14, 1996
Export Citation:
Assignee:
Mitsubishi Electric Corporation
International Classes:
G01R19/00; H02H3/08; H02H3/087; H02H3/093; H02H7/12; (IPC1-7): H02H3/08; G01R19/00; H02H3/087; H02H3/093; H02H7/12
Domestic Patent References:
| JP6217450A | ||||
| JP6233519A |
Attorney, Agent or Firm:
Kaneo Miyata (1 person outside)