Magnetron Power Supply Control for Over-Temperature Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Microwave ovens with magnetrons experience reduced service life due to over-temperature states, particularly in enclosed or no-load conditions, leading to inefficient operation and reduced longevity.

Innovation Solution

A driving power supply system that includes a rectification filtering circuit, frequency conversion circuit, and processing circuit to detect electrical parameters of a switching device, adjusting these parameters to prevent the magnetron from entering over-temperature states by controlling the magnetron's voltage and conduction pulse width.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the magnetron operates under harsh conditions (enclosed state or no-load state), then the heating function is achieved, but the magnetron enters an over-temperature state which reduces service life

Engineering Contradiction:
Improveheating functionVSAvoidservice life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The processing circuit detects electrical parameters (voltage or conduction pulse width) of the switching device and uses this feedback to determine the magnetron's temperature state. Based on the detection result, the system adjusts the switching device's electrical parameters to control the magnetron's operating voltage, preventing prolonged over-temperature operation and extending service life while maintaining heating functionality

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the electrical parameters of the switching device (voltage or conduction pulse width) to regulate the magnetron's operating voltage. By dynamically adjusting these parameters based on detected conditions, the magnetron is prevented from operating in an over-temperature state, thus resolving the contradiction between maintaining heating performance and ensuring reliability

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the magnetron operates in an over-temperature state, then heating performance is maintained, but the operating voltage decreases leading to reduced efficiency

Engineering Contradiction:
Improveheating performanceVSAvoidoperating efficiency
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The processing circuit continuously monitors the electrical parameters of the switching device and uses this feedback to detect changes in the magnetron's operating voltage. When the magnetron enters an over-temperature state causing voltage decrease, the system responds by adjusting the switching device's electrical parameters to restore optimal operating voltage, thereby maintaining heating performance while improving energy efficiency

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the electrical parameters of the switching device to regulate the magnetron's operating voltage in real-time. This parameter adjustment ensures that even when the magnetron operates in over-temperature conditions, the operating voltage is maintained at efficient levels, preventing energy waste while preserving heating performance

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents prolonged operation in over-temperature states, thereby extending the magnetron's service life and ensuring efficient operation.

Implementation Method 1

a rectification filtering circuit configured to be connected to an alternating-current power supply

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 2

a rectification filtering circuit configured to be connected to an alternating-current power supply

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Implementation Method 3

The transformer comprises a primary coil and a secondary coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 4

detect an electrical parameter of the switching device

Methodology Applied
Scientific EffectElectrical parameter detection: Ohmmeter

Data Source

PatentEP4712696A1Driving power source and control method therefor, and heating apparatus and microwave cooking device
Publication Date: 2026.03.18 GUANGDONG WITOL VACUUM ELECTRONICS MFR
  • EP4712696A1 patent drawingFigure 1
  • EP4712696A1 patent drawingFigure 2
  • EP4712696A1 patent drawingFigure 3~4

AI summary

Provided is a driving power supply (100) and a control method therefor, a heating device (1000), and a microwave cooking appliance. The driving power supply (100) includes a rectification filtering circuit (10), a frequency conversion circuit (20), and a processing circuit (30). The frequency conversion circuit (20) includes a transformer (21) and a switching device (22) connected to a primary coil (211). A secondary coil (212) is connected to a magnetron (200). The rectification filtering circuit (10) is connected to an alternating-current power supply (300), and the primary coil (211) is connected to the rectification filtering circuit (10). The processing circuit (30) controls the switching device (22) to be turned on or turned off, and is configured to, in response to an electrical parameter of the switching device (22) meeting a predetermined condition, determine that the magnetron (200) is in an over-temperature state and adjust the electrical parameter to bring the magnetron (200) into a non-over-temperature state.