Induction heating apparatus using a pair of inversely parallel connected gate-controlled switching devices
US4074101A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1976 |
| Grant date | Feb 14, 1978 |
| Priority date | — |
| Expiry date | Feb 11, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S55/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An induction heating apparatus comprising a pair of inversely parallel-connected gate-controlled switching devices connected to an alternating current source, a resonant circuit including an induction heating coil and a variable frequency gating circuit for firing the switching devices to generate oscillations through the conducting device and the induction heating coil. The switching devices are gated into conduction in succession in a first order during the positive half cycle of the alternating current and in a reversed order during the negative half cycle. A zero crosspoint detector is provided to inhibit gating when the source voltage is near zero crosspoint level and to control the gating frequency in accordance with the instantaneous value of the source voltage to increase the turn-off time of the switching devices for lower input source voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.