GB2199998A - Drive circuitry for a microwave source of a microwave oven - Google Patents

Drive circuitry for a microwave source of a microwave oven Download PDF

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Publication number
GB2199998A
GB2199998A GB08631005A GB8631005A GB2199998A GB 2199998 A GB2199998 A GB 2199998A GB 08631005 A GB08631005 A GB 08631005A GB 8631005 A GB8631005 A GB 8631005A GB 2199998 A GB2199998 A GB 2199998A
Authority
GB
United Kingdom
Prior art keywords
microwave
source
microwave oven
drive circuitry
microwave source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08631005A
Other versions
GB8631005D0 (en
Inventor
Harold Croft
Christopher James Wheeler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08631005A priority Critical patent/GB2199998A/en
Publication of GB8631005D0 publication Critical patent/GB8631005D0/en
Publication of GB2199998A publication Critical patent/GB2199998A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/66—Circuits
    • H05B6/666—Safety circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/337—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in push-pull configuration
    • H02M3/3372—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in push-pull configuration of the parallel type

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of High-Frequency Heating Circuits (AREA)

Abstract

Circuitry of a microwave source of a microwave oven comprises electrical switching means (1, 2, 3) operable from a DC source and means (6, 7, 8, 9, 10, 11, 12) for converting an output of the switching means to a high voltage for use in operating the microwave source. The switching means comprises an oscillator the output from which charges capacitor 6, which is discharged through transformer T2 by means of a neon switch 7. <IMAGE>

Description

DRIVE CIRCUITRY FOR A MICROWAVE SOURCE OF MICROWAVE OVEN The present invention relates to drive circuitry for a microwave source (such as a magnetron or a klystron) of a microwave oven.
According to the present invention, there is provided drive circuitry for a microwave source of a microwave oven, comprising electrical oscillator means operable from a D.C. source and means for converting an output of the oscillator means to a high voltage for use in operating the source.
The D.C. source could, for example, be a 12v or 24v battery of a vehicle or 110v , for example.
The present invention will now be described, by way of example, with reference to the single figure of the accompanying drawing, which is a circuit diagram of an example of drive circuitry for the magnetron of a microwave oven.
Referring to the single figure of the accompanying drawing, an integrated circuit type GG6 timer 1 is connected across a 12v supply and ground potential and has an input connected to rtceive a reference voltage (Vref.) for setting the power output of the drive circuitry. Two timing outputs of circuit 1 are connected to the bases of transistors 2 and 3 respectively, the emitters of these transistors being connected to ground potential and their collectors being connected to opposite ends of the primary winding 4 of a 5v to 240v transformer T1. The winding 4 is centre-ta,pped to the 12v supply and there are connected across the secondary winding 5 of transformer T1 a capacitor 6 and in parallel with it a neon switch 7.The capacitor 6 (which may be of a value up to 470pF for example) and the neon switch 7 are also connected in parallel across the primary winding 8 of a further step-up transformer T2. Connected across the secondary winding 9 of transformer T2 is a series connection of three (for example) capacitors 10, 11 and 12 each of which is (for example) a 470of capacitor.
Connected to one terminal (the EHT terminal) of secondary winding 9 is the collector of a transistor 13, whose emitter is connected to energise the heaters of a magnetron, the EHT terminal supplying a high voltage for operating the magnetron. The magnetron (not shown) provides a microwave source of a microwave oven, the oven having a section which houses the drive circuitry shown in the drawing. A capacitor 14 (for example a 470of capacitor) is connected between the collector and base of transistor 13 and a capacitor 15 (for - example a 470 pF capacitor) is connected between the collector and emitter of transistor 13.
The base of transistor 13 is connected to the 12v supply.
The drive circuitry operates as follows. Transistors 2 and 3 act as a variable oscillator which drives the primary winding 4 of transformer T1. The frequency of oscillation is determined by the reference voltage applied to- timing circuit 1 and hence the frequency of the timing pulses applied to transistors 2 and 3. The output of transformer T1 across secondary winding 5 charges capacitor 6 until neon switch 7 is activated to- drive the primary winding of transformer T2 from approximately 300v instantaneous to ground potential.
The resultant output across the secondary winding 9 of transformer T2 is (for example) in the range from 2 - 20kv depending on the frequency of oscillation as determined by the reference voltage and provides the operating (EHT) voltage for the magnetron. The voltage for the heaters at the emitter of transistor 13 is a voltage regulated at (for example) about 4v with reference to the EHT voltage.

Claims (5)

1. Circuitry for a microwave source of a microwave oven, comprising electrical switching means operable from a DC source and means for converting an output of the switching means to a high voltage for use in operating the microwave source.
2. Circuitry according to claim 1, wherein the said switching means comprises oscillator means.
3. Circuitry according to claim 1 or 2, wherein the said converting means comprises capacitor means charged by the output of the said switching means, a neon switch activated when the capacitor means attains a certain charging value and transformer means connected across the neon switch.
4. Circuitry for a microwave source of a microwave oven, substantially as herein described with reference to the accompanying drawing.
5. A microwave oven provided with circuitry according to any preceding claim for operating its microwave source.
GB08631005A 1986-12-30 1986-12-30 Drive circuitry for a microwave source of a microwave oven Withdrawn GB2199998A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08631005A GB2199998A (en) 1986-12-30 1986-12-30 Drive circuitry for a microwave source of a microwave oven

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08631005A GB2199998A (en) 1986-12-30 1986-12-30 Drive circuitry for a microwave source of a microwave oven

Publications (2)

Publication Number Publication Date
GB8631005D0 GB8631005D0 (en) 1987-02-04
GB2199998A true GB2199998A (en) 1988-07-20

Family

ID=10609657

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08631005A Withdrawn GB2199998A (en) 1986-12-30 1986-12-30 Drive circuitry for a microwave source of a microwave oven

Country Status (1)

Country Link
GB (1) GB2199998A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2291322A (en) * 1994-07-12 1996-01-17 Samsung Electronics Co Ltd Microwave oven
GB2296415A (en) * 1994-12-23 1996-06-26 Stephen Marks Microwave oven
GB2354648A (en) * 1999-09-21 2001-03-28 Samsung Electronics Co Ltd Magnetron driving circuit

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1036565A (en) * 1963-08-09 1966-07-20 Wolseley Engineering Ltd Improvements in or relating to electric supply arrangements
GB1366619A (en) * 1971-11-23 1974-09-11 Bendix Corp Battery powered blasting machine with a controlled energy range
EP0171170A2 (en) * 1984-08-02 1986-02-12 Kenwood Limited Microwave oven
EP0205642A1 (en) * 1985-06-24 1986-12-30 Deutsche Thomson-Brandt GmbH D.C. to D.C. converter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1036565A (en) * 1963-08-09 1966-07-20 Wolseley Engineering Ltd Improvements in or relating to electric supply arrangements
GB1366619A (en) * 1971-11-23 1974-09-11 Bendix Corp Battery powered blasting machine with a controlled energy range
EP0171170A2 (en) * 1984-08-02 1986-02-12 Kenwood Limited Microwave oven
EP0205642A1 (en) * 1985-06-24 1986-12-30 Deutsche Thomson-Brandt GmbH D.C. to D.C. converter

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2291322A (en) * 1994-07-12 1996-01-17 Samsung Electronics Co Ltd Microwave oven
FR2722559A1 (en) * 1994-07-12 1996-01-19 Samsung Electronics Co Ltd MICROWAVE OVEN
GB2296415A (en) * 1994-12-23 1996-06-26 Stephen Marks Microwave oven
GB2354648A (en) * 1999-09-21 2001-03-28 Samsung Electronics Co Ltd Magnetron driving circuit
US6222169B1 (en) 1999-09-21 2001-04-24 Samsung Electronics Co., Ltd. Surge-resistant magnetron circuit for use with DC power source

Also Published As

Publication number Publication date
GB8631005D0 (en) 1987-02-04

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)