How to use the wireless charger

2020-12-11 16:08:54

How to use the wireless charger

 1 Introduction to wireless charger

  Wireless charger refers to a device that uses the principle of electromagnetic wave induction for charging, which is similar to a transformer. There is a coil at the transmitting and receiving ends. The transmitting end coil is connected to a wired power supply to generate electromagnetic signals. The receiving end coil induces the electromagnetic signal at the transmitting end to generate current to charge the battery. During the charging process, there is a lot of radiation and the charging efficiency is not high.


   A British company invented a new type of wireless charger, which looks like a plastic mouse pad. You can charge your mobile phone on the pad and charge multiple devices at the same time.

   According to the British "New Scientist" magazine published on the 22nd, this "mouse pad" is equipped with a dense array of small coils, which can generate a magnetic field and transfer energy to electronic devices equipped with special receiving coils for charging. The receiving coil is made of a magnetic alloy wound with a wire, similar in size and shape to chewing gum, and can be easily attached to electronic equipment.

   Wireless charging technology has appeared before, but this new invention is more convenient and practical. As long as the receiving coil is attached to mobile phones and other devices, they can be charged anywhere on the "mouse pad", unlike some previous technologies that require precise positioning. Several devices are placed on the mat at the same time and can be charged simultaneously. The magnetic field generated by the charger is very weak and can charge the device without affecting nearby credit cards, video tapes and other items that use magnetic data to record data.

  Prospect: The principle of this technology is to create an electromagnetic field for parallel micro-charging. Such charging methods have appeared in watches and shavers in the past, but they cannot effectively charge large-capacity lithium-ion batteries.

It uses AC induction technology, and the transmitter and receiver have corresponding coils to send and receive current signals (of course, it takes a little effort to add this receiver in the design of the receiving device where there is not ample space); so there must be radiation The problem; and different devices require different receiving ends, which is not convenient to use; the price is not low.

  2 On the principle of wireless charging technology

  2.1 Where does the power of the wireless charger come from

  If the current passes through the coil, a magnetic field will be generated; and the generated magnetic field will form a voltage. After the voltage is present, a current is generated, and the current can be charged. This is how PowerMat’s wireless charger gets rid of the shackles of wires.

  2.2 How to control the charging process of the charger on and off

   For the current mobile phone chargers, just unplug the cable after charging, then how does the wireless charger solve it? This is about a patent with the title of INDUCTIVE TRANSMISSION SYSTEM and the number WO09116025A found in the patent database.

  According to the database, the applicant for this patent is PowerMat. The main content is to explain the structure of the wireless charger and how the charger works. It is mentioned in the article that the wireless charger contains a device that is turned on and off by monitoring the half-rectified wave, which is what we call the switch device of the wireless charger.

  2.3 About the structure of the wireless charger

  PowerMat design drawing


  PowerMat's wireless charger is divided into two parts, one is the charging board for wireless charging power supply, and the other is the charging power receiver installed on mobile phones or other products that need to be charged.

  2.4 How PowerMat works

   Between the charging board and the receiver of the PowerMat wireless charger, a frequency induction device is used to induce each other. After the two sense each other, they can start to provide electromagnetic induction charging for the mobile phone. At the same time, that PowerMat applied for a patent, a device that can monitor half-rectified waves, and controls the charging switch.

  3 The limitations of wireless chargers at this stage

  Although this wireless charger looks quite cool, handsome and convenient, it is a new technology that has not been popularized after all, and there are some limitations in some aspects.

   As far as the current situation is concerned, wireless chargers cannot reach the coverage of a wireless network. Although the charging board and the receiver are two parts, they still cannot be separated too far from each other, otherwise the charging efficiency will be drastically reduced or even unable to charge.

   In addition, the conversion rate of wireless charger charging is much lower than that of wired chargers. At present, it can only reach 70%, which is a waste of energy. Of course, this is already a very good effect.