Electrical operating circuit having semiconductor device junction temperature monitoring
US4039928A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1976 |
| Grant date | Aug 2, 1977 |
| Priority date | — |
| Expiry date | Jul 19, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0027
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An operating circuit for a semiconductor switch device of the type that passes electrical current from a source to an electrical load by forward biasing of the semiconductor's control terminal includes a resistance bridge network having in an arm thereof the control terminal to one main terminal circuit of the semiconductor switch, and a bias control for alternately applying forward bias and reverse bias to the control terminal through the bridge network, whereby a voltage is developed across the bridge output during the interval in which the control terminal is reverse biased that is representative of the junction temperature within the semiconductor. The temperature representative voltage is observed, monitored, and used for indication and control. In a further embodiment the bias control operated periodically and includes inhibit means responsive to the derived temperature representative voltage exceeding a certain level, representative of a temperature maximum, for retaining the control terminal of the semiconductor in the back biased condition, until the derived voltage reduces in level thereby protecting the semiconductor from thermal burn-out. In a welding control circuit pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.