Microwave heating apparatus for reducing high-frequency in an electric power circuit

• US 5,639,395 A
• Filed: 11/16/1995
• Issued: 06/17/1997
• Est. Priority Date: 11/17/1994
• Status: Expired due to Fees

• Current Assignee: LG Semicon Co Ltd (SK Hynix Inc.)
• Original Assignee: LG Semico Company Limited (SK Hynix Inc.)
• Inventors: Lee, Ki-Yeoung
• Primary Examiner(s): Leung, Philip H.
• Application Number:
  US08/558,522
• Time in Patent Office: 579 Days
• Field of Search: 219/716, 219/715, 219/702, 219/717, 219/718, 363/56, 363/55, 363/74
• US Class Current: 219/716
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H05B 6/666 Safety circuits emergency protective circuits in general H02H

Abstract

A microwave heating apparatus is disclosed. The microwave heating apparatus includes: a rectifying section for rectifying an AC current; an inverting section for being turned on/off by the driving signals of a driving section to generate high frequency voltages corresponding to the output signals of the rectifying section; a microwave generating section for receiving the output signals of the inverting section to generate microwaves; a synchronization detecting section for detecting synchronizing signals from the output signals of the inverting section; and a flip flop for being set and reset by the output signals of the synchronization detecting section to control the driving section. The apparatus of the present invention further includes a synchronization control section disposed between the synchronization detecting section and the flip flop, so that the synchronization control section can detect the period of the output signals of the synchronization detecting section to compare it with a reference value so as to reset the flip flop upon encountering a period smaller than the reference value, and so as to prevent the driving section from driving the inverting section.

Claims

1. A microwave heating apparatus comprising:

a rectifying section for rectifying an AC power input;

an inverting section for generating high frequency voltages corresponding to output signals of said rectifying section by being turned on/off in accordance with driving signals of a driving section;

a microwave generating section for generating microwaves in response to output signals of said inverting section;

a synchronization detecting section for detecting synchronizing signals from the output signals of said inverting section, and making an output signals; and

a flip flop for being set and reset by output signals of said synchronization detecting section, to control said driving section, and

the apparatus further comprising;

a synchronization control section connected between said synchronization detecting section and said flip flop, wherein

said synchronization control section detects periods of the output signals of said synchronization detecting section to compare it with a reference value so as to reset said flip flop upon encountering a period smaller than the reference value, whereby said driving section is prevented from driving said inverting section.

2. The apparatus as claimed in claim 1, wherein said synchronization control section comprises:

a counter connected to the output signals of said synchronization detecting section;

a data setting section for setting a reference value;

an AND gate for receiving an output of said comparator and the output of said synchronization detecting section through its two input terminals and connecting its output to said flip flop.