Our lives are becoming more dependent on wireless electronic devices operating using batteries. This has made it essential to charge the batteries of these electronic gadgets. During the initial days of wireless charging, it was not preferable option compare to wired charger technologies due to charging time needed and magnitude of current produced by wireless chargers.
WPC(Wireless Power Consortium) has introduced Qi power standard which was inductive in the year 2008 for wireless charging application. With this chargers could produce limited current and power consumption was about 5 Watts. Recently Qi devices are available to deliver power upto about 120 watts. With latest advancement and technologies wireless chargers can produce current in the magnitude of 1 Amperes.
Figure depicts Qi compliant wireless charging pad model WCP 300 from LG. There are various standards evolving to support wireless charging need from consumer and mobile market. Latest in the series are PMA (Power Matter Alliance) and A4WP (Alliance for Wireless Power) introduced recently. BCM59359 device from Broadcom allow any of the above mentioned standard compliant devices to be charged wirelessly.
Types of Wireless Charger
There are two main types of wireless chargers viz. inductive charging and resonance charging.
In the inductive type there are two coils; primary coil and secondary coil.
In the primary coil wires are connected to AC Mains. The magnetic flux is produced in the secondary coil using induction.
This magnetic flux generates the current required for charging the device.
The other type is based on A4WP standard. In resonane type of charging more than one device can be charged wirelessly by placing all of them within the reach of wide resonant field. A4WP compliant wireless chargers work at frequency of 6.78KHz which is the standard international frequency. 2.4GHz is used for control and management of these devices. The main difference between inductive type and resonant type of wireless charging is teh coupling factor. Inductive type has coupling factor higher than the later one.
wireless charging solution manufacturers
Wireless charger market is booming as mentioned due to emergence of cheap electronic devices. Many companies are manufacturing devices for this market compliant to various standards as mentioned. They have produced single coil based power transmitter, power application controller, slip ring, wireless connector, power receiver, charging PMU etc.
Following are the wireless charging solution manufacturers.
Qi Wireless charging basics and how it works
For basics of Qi wireless charging and mentions how does Qi wireless charging work. Refer Qi Wireless charging➤