Induction heating apparatus with protective circuit arrangement
US4016390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1975 |
| Grant date | Apr 5, 1977 |
| Priority date | — |
| Expiry date | May 22, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/525
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An induction heating apparatus is provided with protective circuit arrangements which ensure against surge currents caused by inappropriately timed gating-on of a gate controlled rectifier or by erroneous use of a load material such as non-magnetic or ferromagnetic material. The timed gating of the gate-controlled rectifier is accomplished by means of a delay circuit which serves to count timing after a rectified excitation potential drops to the zero voltage point. A coincidence circuit is provided to detect coincidence of two signals, one is a pulse having a predetermined width and the other is a signal derived when the periodic cycle of the energization currents departs from the predetermined cycle period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.