Power Reception Control Circuit for Wireless Charging Overvoltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless power supply systems, a time lag in power transmission stoppage can lead to excessive voltage application at the power reception device due to low communication speed or delayed signal processing, potentially damaging the device or its load.
Innovation Solution
A power reception device with a control circuit that includes a switch and a rectification element, which shorts the positive and negative electrodes when the load voltage exceeds a predetermined value, preventing excessive voltage application and ensuring the load is not short-circuited, thereby controlling current flow to prevent overvoltage and overcurrent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power reception device waits for communication confirmation before stopping power reception, then power transmission can be stopped based on load status, but excessive voltage is applied to the load due to time lag
Solution Approach 1:
The patent applies preliminary action by proactively detecting voltage abnormalities and preemptively activating protection mechanisms before excessive voltage can damage the load. The control circuit continuously monitors voltage levels and triggers the discharge path activation when voltage exceeds safe thresholds, preventing harmful effects before they occur.
Solution Approach 2:
The patent introduces an intermediary protection circuit between the power reception coil and the load. This intermediary circuit includes a control circuit that detects voltage abnormalities and activates a discharge path with a switching element and discharge resistor, serving as a buffer that protects the load from excessive voltage while allowing normal power transmission to proceed.
2Object-affected harmful factors
If a switch is activated to short-circuit the control circuit during overvoltage, then excessive voltage is suppressed, but the load may be short-circuited causing current damage
Solution Approach 1:
The patent uses an intermediary discharge resistor connected in parallel with the load through a switching element. When overvoltage is detected, the switching element activates to provide an alternative current path through the discharge resistor, preventing direct short-circuiting of the load while still suppressing excessive voltage. The discharge resistor acts as a mediator that safely dissipates excess energy.
Solution Approach 2:
The patent changes the electrical parameters of the circuit by dynamically altering the resistance configuration. During normal operation, the discharge path has high resistance (switching element off). During overvoltage conditions, the switching element activates to change the resistance to a lower value, providing a controlled discharge path that limits current while suppressing voltage spikes.
3Loss of time
If communication speed is increased or signal processing is accelerated, then time lag is reduced, but device complexity and cost increase
Solution Approach 1:
The patent implements self-service by enabling the power reception device to autonomously monitor its own voltage status and independently activate protection mechanisms without requiring external communication or control signals. The control circuit continuously self-monitors voltage levels and automatically triggers the discharge path when needed, eliminating dependence on communication speed or external signal processing.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the discharge path and protection circuitry to be immediately available, with continuous voltage monitoring already in place. When overvoltage occurs, the protection mechanism activates instantly based on pre-established voltage thresholds, without requiring communication confirmation or complex signal processing delays.
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 configuration effectively suppresses excessive voltage application, reduces the risk of load discharge, and allows for a cost-effective and compact power reception device design by focusing on overvoltage countermeasures rather than overcurrent resistance.
Implementation Method 1
a power reception coil that receives electric power transmitted from a power transmission coil
Implementation Method 2
a rectification circuit that rectifies alternating current power received by the power reception coil
Data Source
AI summary
Provided are a power reception device and a power reception control method capable of suppressing the application of an excessive voltage even in the case where a time lag occurs before power transmission by a power transmission device is stopped after disconnection between the power reception device and a load. A power reception device includes: a power reception coil that receives power transmitted from a power transmission coil; a rectification circuit that rectifies alternating current power received by the power reception coil; and a control circuit that is connected between the rectification circuit and a load to which direct current power outputted from the rectification circuit is supplied, and controls that the direct current flowing through the load to be constant or equal to or less than a predetermined value by the direct current power.