Title:
HIGH FREQUENCY HEATING DEVICE
Document Type and Number:
Japanese Patent JP3158816
Kind Code:
B2
Abstract:
PURPOSE: To provide an overvoltage protection means for a semiconductor switching element in a high frequency heating device using an inverter power supply having the semiconductor switching element.
CONSTITUTION: A inverter power supply 6 is provided with a forced commutation circuit 25 having a breakdown voltage quantity set lower than a breakdown voltage of a semiconductor switching element 11, and a drive voltage detection means 27 and a terminal voltage detection means 29 are provided. In the case where an overvoltage is generated between terminals of the semiconductor switching element 11, the forced commutation circuit 25 becomes continuous, it is detected by the drive voltage detection means 27, and the inverter power supply 6 is stopped or temporarily stopped. Otherwise, the inverter power supply 6 is stopped or temporarily stopped by comparison of the terminal voltage detection means 29 with a reference voltage generation means 28. With this constitution, the semiconductor switching element having the necessary minimum breakdown voltage can be applied, and voltage breakdown, etc., can be prevented.
Inventors:
Yoshiro Ishio
Kazuho Sakamoto
Shiro Takeshita
Villa Daisuke
Haruo Suenaga
Toyotsugu Matsukura
Yuji Nakabayashi
Makoto Shibuya
Kazuho Sakamoto
Shiro Takeshita
Villa Daisuke
Haruo Suenaga
Toyotsugu Matsukura
Yuji Nakabayashi
Makoto Shibuya
Application Number:
JP28343293A
Publication Date:
April 23, 2001
Filing Date:
November 12, 1993
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H05B6/66; H02M7/48; H02M7/537; H05B6/68; (IPC1-7): H05B6/66; H02M7/48; H05B6/68
Domestic Patent References:
| JP1225089A | ||||
| JP2214499A | ||||
| JP6446995U | ||||
| JP4105493U |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)