Method and circuit of determining wireless charging foreign matter based on Q value

Abstract

The invention relates to a method and circuit of determining wireless charging foreign matter based on a Q value. The circuit of determining wireless charging foreign matter based on a Q value includes a wireless transmitting circuit and a detection circuit, wherein the detection circuit is electrically connected with the wireless transmitting circuit; the wireless transmitting circuit emits electromagnetic wave which continuously changes the frequency and enables the wireless transmitting circuit to stop working; and during the process of transmitting the electromagnetic wave from the wireless transmitting circuit, the detection circuit detects the Q value of the wireless transmitting circuit, and according to the detected Q value, determines whether foreign matter exists in the electromagnetic wave transmission range of the wireless transmitting circuit. In the circuit of determining wireless charging foreign matter based on a Q value, the wireless transmitting circuit and the detection circuit are employed; the wireless transmitting circuit emits the electromagnetic wave which continuously changes the frequency and enables the wireless transmitting circuit to stop working; and during the process of transmitting the electromagnetic wave from the wireless transmitting circuit, the detection circuit detects the Q value of the wireless transmitting circuit, and according to thedetected Q value, determines whether foreign matter exists in the electromagnetic wave transmission range of the wireless transmitting circuit. The circuit of determining wireless charging foreign matter based on a Q value has the advantages of being simple in the circuit structure, being low in cost and having no influence on the working efficiency of the system.

Description

technical field [0001] The present invention relates to the technical field of wireless charging foreign object detection, in particular to a method and a circuit thereof for judging wireless charging foreign objects based on a Q value. Background technique [0002] Wireless charging technology has been greatly developed in recent years, and has been applied in various electronic devices, especially in consumer electronics such as mobile phones and has become an emerging hot application. However, the detection of metal foreign objects has always been a problem that needs to be improved. In the early days, the energy loss method was mostly used, but the energy loss method will be affected by factors such as the efficiency of the receiving device itself, the distance between the transmitting coil and the receiving coil, and the bias. It's hard to get very high. [0003] Since the wireless charging / power supply device itself is composed of an RLC oscillating circuit, the RLC c...

AI Technical Summary

Problems solved by technology

However, the detection of Q value is carried out in the resonant frequency range, which will couple high voltage on the transmitting coil and receiving coil, which will cause irreversible damage to the equipment. In order to solve this problem, some people add complex switching to the main power supply circuit. The circuit provides extremely low voltage during Q value detection, and then switches back to normal voltage during normal operation

However, this solution has several disadvantages: 1. The switching circuit is added to the main circuit, which will affect the efficiency of the system during normal operation; 2. Increase the complexity of the circuit; 3. Increase the system cost

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