DE3915542A1 - Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow - Google Patents

Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow

Info

Publication number
DE3915542A1
DE3915542A1 DE19893915542 DE3915542A DE3915542A1 DE 3915542 A1 DE3915542 A1 DE 3915542A1 DE 19893915542 DE19893915542 DE 19893915542 DE 3915542 A DE3915542 A DE 3915542A DE 3915542 A1 DE3915542 A1 DE 3915542A1
Authority
DE
Germany
Prior art keywords
magnetron
anode current
damage during
switching circuit
current flow
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.)
Ceased
Application number
DE19893915542
Other languages
German (de)
Inventor
Uwe Ing Grad Hartmann
Udo Ing Grad Mai
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.)
Vogt Electronic AG
Original Assignee
Vogt Electronic AG
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 Vogt Electronic AG filed Critical Vogt Electronic AG
Priority to DE19893915542 priority Critical patent/DE3915542A1/en
Publication of DE3915542A1 publication Critical patent/DE3915542A1/en
Ceased legal-status Critical Current

Links

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
    • 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
    • H05B2206/00—Aspects relating to heating by electric, magnetic, or electromagnetic fields covered by group H05B6/00
    • H05B2206/04—Heating using microwaves
    • H05B2206/043—Methods or circuits intended to extend the life of the magnetron

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of High-Frequency Heating Circuits (AREA)

Abstract

The magnetron device has a switching system that prevents damage during the preheating stage. The supply is controlled by a resonance circuit that ensures a ramp voltage that increases upto a set level. The level is set such that there is no magnetron anode current during the preheat period. USE/ADVANTAGE - For microwave oven for food preparation . Prevents damage during preheating period.

Description

Magnetrons werden vorzugsweise in Mikrowellenöfen für die Zubereitung von Speisen eingesetzt. Diese Magnetrons werden bisher von Netzteilen gespeist, die mit Blechtrafos für die 50 (60)Hz Netzfrequenz ausgestattet sind. Diese Trafos sind für die beachtlichen Leistungen von 400 Watt und darüber groß und schwer und haben darüber hinaus den Nachteil des hohen Einschaltstromstoßes, wenn dagegen keine Vorkehrungen getroffen werden.Magnetrons are preferably used in microwave ovens for preparation of dishes used. These magnetrons are currently used by power supplies powered with metal transformers for the 50 (60) Hz mains frequency are. These transformers are for the remarkable outputs of 400 watts and about it big and heavy and also have the disadvantage of high Inrush current if no precautions are taken.

Die Verwendung von Schaltnetzteilen bietet eine Reihe von Vorteilen, wie geringeres Gewicht, bessere Regelbarkeit und wenig Rückwirkung auf das Stromversorgungsnetz. Allerdings sind eine Reihe von schaltungstechnischen Maßnahmen zu treffen, die erfindungsgemäß in den Patentansprüchen niederge­ legt sind.The use of switching power supplies offers a number of advantages, such as lower weight, better controllability and little feedback on the Power supply network. However, there are a number of circuitry related To take measures that according to the invention in the claims sets are.

Claims (3)

1. Schaltnetzteil zum Betreiben eines Magnetrons, das im Current-mode-, Durchfluß-, sowie im Sperrwandlerbetrieb arbeitet, das durch einen Resonanzkreis eine feste Freilaufzeit aufweist, wobei die während der Freilaufzeit nicht entnommene Energie während der Durchflußzeit in den Ladekondensator zurückgespeichert wird, dadurch gekennzeichnet, daß eine der ausgangsseitigen Wechselspannung proportionale Rampenspannung erzeugt wird, die bei Ansteigen dieser Wechselspannung über eine vorgegebene Schwelle hinaus die Paketbreite begrenzt.1. Switching power supply for operating a magnetron, which works in current mode, flow, and flyback converter mode, which has a fixed free-running time through a resonance circuit, the energy not removed during the free-running time being stored back into the charging capacitor during the flow time, thereby characterized in that a ramp voltage proportional to the output AC voltage is generated, which limits the packet width when this AC voltage rises above a predetermined threshold. 2. Schaltnetzteil nach Anspruch 1, dadurch gekennzeichnet, daß die Schwelle derart dimensioniert ist, daß während der Vorheizzeit, bei der noch kein Magnetronanodenstrom fließt, das Magnetron nicht beschädigt wird.2. Switching power supply according to claim 1, characterized in that the threshold is dimensioned such that during the preheating period, at which no Magnetron anode current flows, the magnetron is not damaged. 3. Schaltnetzteil nach Anspruch 1 und 2, dadurch gekennzeichnet, daß zur Leistungssteuerung im Normalbetrieb die Paketbreite herangezogen wird, wobei bei gleichbleibender Leistung die Paketbreite umgekehrt proportional zu der Netzspannung ist.3. Switching power supply according to claim 1 and 2, characterized in that for Power control in normal operation the packet width is used, the package width being inversely proportional with the same performance to the mains voltage.
DE19893915542 1989-05-12 1989-05-12 Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow Ceased DE3915542A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19893915542 DE3915542A1 (en) 1989-05-12 1989-05-12 Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19893915542 DE3915542A1 (en) 1989-05-12 1989-05-12 Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow

Publications (1)

Publication Number Publication Date
DE3915542A1 true DE3915542A1 (en) 1990-11-15

Family

ID=6380526

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19893915542 Ceased DE3915542A1 (en) 1989-05-12 1989-05-12 Switching circuit for magnetron supply - avoids damage during preheat period by preventing anode current flow

Country Status (1)

Country Link
DE (1) DE3915542A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4142082A (en) * 1975-12-18 1979-02-27 Raytheon Company High frequency power supply microwave oven

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4142082A (en) * 1975-12-18 1979-02-27 Raytheon Company High frequency power supply microwave oven

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Legal Events

Date Code Title Description
8110 Request for examination paragraph 44
8131 Rejection