Sharp Kabushiki Kaisha Corporation

Koji Ueda

Yutaka Takashige

Shinichi Masuda

Kohei Ito

In a high frequency heating apparatus, a microcomputer inputs the phase signal of a commercial AC power supply and determines whether a timer switch in a mechanical timer apparatus is in ON-state to determine whether the high frequency heating apparatus is in a heating-time set state. If so, the microcomputer turns on a switch that controls the conduction between the commercial AC power supply and a high voltage transformer at such a timing that minimizes the rush current in accordance with the phase of the commercial AC power supply, thereby suppressing the rush current, allowing the user to visually confirm the remaining heating time, and realizing a cost reduction.

High frequency heating apparatus with displacement identifiable remaining heating duration and phase control based thereon

A high-frequency heating apparatus is designed to maximize the input current while securing a uniform margin relative to the cutoff current, thereby enabling maximized and efficient output of high-frequency waves. The high-frequency heating apparatus includes: a power supply unit; an input current detector; a power converting unit for converting the power from the power supply unit into high-frequency waves; an inverter controller for controlling a semiconductor device; a magnetron for radiating electromagnetic waves; and a circuit for implementing negative feedback control, in the inverter control circuit, of the output from the input current detector. The apparatus further includes a control circuit having a microcomputer for outputting signals to the inverter controller so as to control the input current such that the input current characteristic of the high-frequency heating apparatus will approximate the current cutoff characteristic of the overcurrent circuit breaker with respect to the elapsed time.

Growing community of inventors

Minoo, Japan

Koji Ueda