Induction Heating Coil Control via Semiconductor Switches
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Solution Overview
Problem
Existing induction heating and wireless power transmitting apparatuses experience noise issues during switching operations and have bulky circuits due to the use of relays and object detection circuits, which affect performance and user satisfaction.
Innovation Solution
The apparatus employs semiconductor switches to independently control and turn on/off multiple working coils, eliminating the need for relays and object detection circuits, thereby reducing noise and circuit volume, and uses a controller to manage the semiconductor switches for high-speed object detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If relays and object detection circuits are used to control working coils, then switching operation can be achieved, but noise is generated during switching and circuit volume increases
Solution Approach 1:
The patent replaces mechanical relays with semiconductor switches (MOSFETs or IGBTs) to control the working coils. This substitution eliminates the mechanical contact and magnetic field generation associated with relays, thereby removing the source of switching noise while maintaining the coil control functionality. The semiconductor switches are directly controlled by the controller to achieve reliable switching operation without generating harmful noise.
2Reliability
If relays and object detection circuits are used to control working coils, then switching operation can be achieved, but circuit volume increases
Solution Approach 1:
The patent extracts and removes the object detection circuit from the system by implementing object detection functionality directly within the controller. The controller detects objects by monitoring the current flowing through the working coils without requiring a separate detection circuit. This extraction eliminates unnecessary circuit components and reduces overall circuit volume while maintaining reliable switching operation.
Solution Approach 2:
The controller is designed to perform multiple functions: it controls the semiconductor switches for coil switching and simultaneously detects objects by monitoring coil current. This multi-functionality consolidates what would traditionally require separate circuits into a single integrated control unit, thereby reducing circuit volume without compromising switching reliability.
3Object-affected harmful factors
If semiconductor switches are used to control working coils, then noise is reduced and circuit volume is minimized, but high-speed switching control is required
Solution Approach 1:
The patent utilizes the inherent electrical parameters of semiconductor switches, particularly their fast switching capability, to achieve high-speed coil control. By selecting semiconductor devices with appropriate switching characteristics and designing the control circuitry to exploit these parameters, the system achieves both noise reduction and high-speed operation. The controller is configured to generate switching signals at frequencies and durations optimized for the semiconductor switch performance.
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
This solution enables fast and noise-free operation, improves user satisfaction by reducing noise sensitivity, and minimizes the overall volume of the apparatus, enhancing usability and space utilization.
Implementation Method 1
a first inverter configured to perform a first switching operation to generate a first resonant current in at least one of the first working coil or the second working coil
Implementation Method 2
a first semiconductor switch that is connected to the first working coil and that is configured to turn on and turn off the first working coil
Data Source
AI summary
An induction heating and wireless power transmitting apparatus includes a first group of working coils including a first working coil and a second working coil connected to each other in parallel, a first inverter that supplies resonant currents to at least one of the first working coil or the second working coil by performing a switching operation, a first semiconductor switch connected to the first working coil configured to turn on and turn off the first working coil, a second semiconductor switch connected to the second working coil and configured to turn on and turn off the second working coil, an auxiliary power supply configured to supply power to the first semiconductor switch and the second semiconductor switch, and a controller that controls the first inverter, the first semiconductor switch, and the second semiconductor switches.