Oscillator circuit for controlling the power level of a microwave oven
US4323861A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1979 |
| Grant date | Apr 6, 1982 |
| Priority date | — |
| Expiry date | Mar 29, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/24
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An oscillator circuit having a variable duty cycle for controlling the power level of a microwave oven provides an adjustable RC time constant circuit including a capacitance branch and a resistance branch and coupling means therebetween, the resistance branch including a pair of alternately selectable current paths for the charging and discharging of the capacitance branch, the coupling means including semiconductor switch means for selecting and coupling either of the current paths to the capacitance branch for changing the charging and discharging of the capacitance branch in accordance with the selected current path, and one of the current paths including a pair of parallel connected portions with each of the parallel portions having a diode connected therein for controlling the direction of current flow, the diodes being connected with opposite respective polarities for allowing current flow only in opposite directions in the respective portions, the one current path further including a potentiometer having a pair of fixed terminals each of which is connected to a separate parallel portion and a variable wiper terminal connected to the first coupling means for simultaneously i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.