Comparison of wireless charging and wired charging(一)

There are many wireless chargers and wireless charging treasures on the market, with different prices, so I made a comparison of current charging methods-wired charging vs. wireless charging.

一: Security The safety issue is the core issue of the device, and for wireless/wireless charging, the security issue is designed in three aspects.

1. Leakage Wired charging-there is a small chance of leakage. There is a certain chance of electric shock when the charger is used or improperly used. After all, wired charging still requires contact operation.

Wireless charging-almost no possibility of electric shock. Just put it on when charging, there is no direct contact, there is almost no chance of electric shock.

wireless charger

2. Radiation Wired charging-general current and magnetic field radiation: Since the current of wired charging is not converted, there will still be radiation generated, but only general magnetic radiation, coupled with low current and voltage, has negligible impact on the human body.

Wireless charging-current magnetic field enhanced radiation: since wireless charging needs to be transformed by a magnetic field, there is a deliberately increased magnetic field, which will still affect the human body for a long time at a short distance (within 20cm), but normal use (outside 20cm, magnetic field Serious attenuation) Theoretically, radiation has no effect.

3. Fever Wired charging-Excluding the heat generated by the charger/power bank and the battery charging process, generally wired charging generates very little heat, and the impact on the device can be ignored. Under various fast charging and high-current charging nowadays, the heating of wired charging has been tested, but because fast charging and high-current charging have certain technical requirements for the wire, the heating problem cannot have much impact. Wireless charging-Excluding the heat generated by the charger/power bank and the battery charging process, the general wireless charging heat is more serious than wired. The heat generation comes from the impedance and dense winding of the coil, and because the receiving part of the wireless charging device is built into the mobile phone , Then due to the heating of the coil and the heating of the battery, the quality of the entire phone has been tested, which will damage the life of the phone to a certain extent, and even cause the battery to overheat and become dangerous.

苹果磁吸无线充-001

4. Charging protection Wired charging-charging protection, the most used now is the current limit, that is to say the normal charging is 5V2A, then the mobile phone will directly limit the current when it is fully charged or at 99%, and only retain the current of about 0.002A. , Even many mobile phones are equipped with high temperature protection, disconnect the line when the phone is hot, and stop charging. This is the safety guarantee for our mobile phones to charge all night. Wireless charging-there is a big difference between wireless charging and wired charging. The most significant point is that the charging process is not controlled by the phone itself, no matter whether the phone is disconnected or the current is limited, as long as the phone is still on the wireless charger , The charger is not powered off, then the power will be converted into current through the magnetic field to charge the mobile phone, which corresponds to a huge test for the charging protection of the mobile phone. In addition to the protection of the line, there is also a big problem that the coil built in the mobile phone is in the magnetic field for a long time. Although the mobile phone is not charged due to the charging protection, the static electricity generated by the coil has nowhere to go. Mobile phones are undoubtedly harmful.

二: Energy consumption In terms of energy consumption, some mobile devices such as mobile phones are not obvious, but the base is huge, and the accumulation is also very scary. Wired charging-low energy consumption, almost no consumption if not used or unplugged. For wired charging, although there is a certain loss in the conversion of voltage and current, it is not too much. In addition, the conversion rate of the electrical energy in the final battery to chemical energy is around 85%. If it is not working and the charger is not unplugged, then the whole short circuit will be almost no loss, but the charger will be damaged by static electricity for a long time (about half a year). Wireless charging-the energy consumption is relatively high, and it will continue to consume electricity without charging or unplugging. Compared with wired charging, the conversion of wireless charging is more than a process of electric energy to magnetic field and magnetic field to electric energy. With current technology, the theoretical maximum conversion is 90%, while the conversion rate of general wireless chargers is around 75%, plus charging During the original 85% conversion rate, the entire charging process is only 60%-75% up and down. The experience is not obvious when there is power, but if you use a power bank, you will find a power bank that can be charged 5 times, charging 4 times It’s gone. And for wireless charging, if the switch is not turned off or unplugged, the magnetic coil will work for 24 hours. If it is on the power supply, it will be a test for the equipment and circuit for a long time; if it is on the power bank, a large amount of spare power will be lost. However, many wireless chargers are now equipped with many sensors. Although many of them are nonsense, many of them can really protect mobile phones. Even if the price is rising, it is not a little bit higher.

wireless power bank6

三: interference There is a magnetic field when there is an electric current, and there is interference when there is a magnetic field, but the strength of the interference is very different. Wired charging-there is current interference, which is relatively weak, and the wire is 10cm away (a larger distance may be required under fast charging) has almost no effect. The charging process is barrier-free to the reception of information, telephone, network, etc., and the interference is almost only some current noise. Wireless charging-there is current interference, magnetic field interference, relatively strong. The interference of wireless charging under non-interference countermeasures can almost make the mobile phone near the device (about 20cm) and other devices without anti-interference equipment appear current noise, snowflakes and other interference phenomena, and the mobile phone being charged may even be unable to receive calls, information, Networking information, etc. With the interference countermeasure circuit, the interference still exists under the interference shielding material, but it is relatively weak.

power bank 34

To be continued

 

 


Post time: Nov-06-2020