Summary of various wireless power supply methods

Among the wireless power supply methods currently used, in addition to the electric field coupling method, there are also electromagnetic induction method, magnetic resonance method and radio wave method.

Electric field coupling wireless power supply technology

The electric field coupling wireless power supply module is composed of two asymmetric dipoles arranged in a vertical direction. Each of the dipoles consists of an activated carbon electrode and a ground electrode for the power supply part and the receiving part. The wireless power supply module is powered by the induced electric field generated by the electric field coupling of the two asymmetric dipoles.

Using this circuit structure, an electric field coupling wireless power supply module with strong positional flexibility and high transmission efficiency was developed.

Basic circuit structure of electric field coupling power supply system

Following is a block diagram of the wireless power delivery system.

The power supply part of the wireless power supply system is composed of a power supply module and a power supply electrode, while the receiving part is composed of a receiving electrode, a receiving module and a DC-DC converter. Through power circuit design technology, a power circuit is designed for the power supply module, and a control circuit that can ensure product safety is installed in the power supply module.

The current converted into alternating current from the power supply module is transmitted to the receiving part after being coupled by the coupling capacitor formed between the power supply electrode and the receiving electrode.

By installing a rectifier circuit and a voltage conversion circuit in the receiving part, the wireless power supply system can provide stable direct current to batteries and electronic devices.

Block Diagram

In the process of power supply using electric field coupling, voltage conversion is required. The following figure is an example of voltage conversion.

Although the current flowing through the wireless power supply part (electric field coupling part) is a high voltage current, since its current value is very small, there is no need to worry about the electrodes heating up.

The following safety measures are taken to control high voltage current.

Block diagram/voltage transition

In order to control the high voltage current of the wireless power supply part, we currently use our own developed safety control technology to ensure that the product has a high degree of safety.

The power supply module has a function capable of detecting the current load and its changes.

By utilizing the above functions, when it is detected that there is no electronic device that needs to be charged on the charging station, or the battery of the electronic device being charged is fully charged, the power supply module will automatically stop supplying power.

By utilizing the above functions, when a metal object or human body that is not a charging target is detected contacting the charging station, the power supply module will automatically stop supplying power.

If discharge occurs, the power supply module will automatically stop supplying power to prevent smoke and fire caused by discharge.

In addition, in order to ensure the safety of electronic devices using wireless power modules, we are providing customers with technical support services for the design of circuit structures around electrodes. This service mainly includes the following two points.

Insulate the electrodes.

Implemented circuit structure design for customers that enables receiving electrodes to be installed inside the housing of electronic equipment.