Induction Cooker Control Device for Empty Vessel Detection
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Solution Overview
Problem
Induction cookers lack effective power control mechanisms to detect empty cooking vessels, which can lead to inefficient energy transfer and potential damage to the induction coil or cooking vessel.
Innovation Solution
A control device with a driving circuit, controller, and temperature measurement system that adapts the power signal based on the temperature gradient of the induction coil to determine the filling level of a cooking vessel, preventing overheating and ensuring safe operation by adjusting the frequency and power output accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the induction coil is driven at resonance frequency for efficient power transfer, then energy transfer efficiency is improved, but the system cannot detect empty cooking vessels leading to potential overheating and damage
Solution Approach 1:
The system performs preliminary detection of the cooking vessel state before initiating full power heating. By measuring parameters such as coil impedance, resonance frequency shifts, or temperature changes during a preliminary phase, the control system can determine whether a cooking vessel is present and properly positioned before applying high power, thus preventing overheating and damage while maintaining efficient operation when the vessel is present
Solution Approach 2:
The system continuously monitors parameters such as coil impedance, resonance frequency, current draw, or temperature during operation and uses this feedback to detect changes indicating an empty or improperly positioned cooking vessel. When the feedback indicates an abnormal state, the control system automatically adjusts or terminates power delivery to prevent damage, while maintaining efficient resonant operation under normal conditions
2Power
If the power signal frequency is increased to raise output power, then power output is improved, but the impedance of the induction coil falls and current increases potentially causing damage
Solution Approach 1:
The system dynamically adjusts the power signal frequency and amplitude based on real-time conditions. By continuously monitoring coil impedance and current draw, the control system can increase frequency to boost power output when appropriate while automatically reducing frequency or amplitude when current approaches dangerous levels, thus achieving high power output without causing coil damage
Solution Approach 2:
The system changes operating parameters such as frequency, amplitude, and duty cycle based on detected cooking vessel presence and conditions. When a cooking vessel is detected, the system can safely increase frequency and amplitude to deliver high power. When no vessel is present or conditions become unsafe, the system adjusts parameters to reduce current and prevent damage, thus achieving variable power output with built-in protection
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
Effectively detects empty cooking vessels by monitoring temperature and frequency gradients, preventing overheating and ensuring efficient energy transfer, thus extending the lifespan of both the induction coil and cooking vessel.
Implementation Method 1
a high frequency power signal is provided to an induction coil. This generates a magnetic field around the induction coil, which is magnetically coupled to a conductive cooking vessel, such as a pan, placed over the induction coil. The magnetic field then generates eddy currents in the cooking vessel, causing the cooking vessel to heat.
Implementation Method 2
The magnetic field then generates eddy currents in the cooking vessel, causing the cooking vessel to heat.
Implementation Method 3
a first measurement device configured to measure a temperature of the induction coil and provide the measured temperature to the controller
Data Source
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AI summary
The present invention provides a control device for an induction cooker, the control device comprising a driving circuit (4) configured to controllably drive an induction coil (6) of the induction cooker (2) with a power signal (5), a controller (7) coupled to the driving circuit (4) and configured to control the driving circuit (4) with a control signal (8) to drive the induction coil (6) with the power signal (5), and a first measurement device (9) configured to measure a temperature (10) of the induction coil (6) and provide the measured temperature to the controller (7), wherein the controller (7) is configured to determine the filling level of a cooking vessel (3) based on the measured temperature (10) and adapt the control signal (8) according to the determined filling level. The present invention further provides a respective method and an induction cooker.