Wireless charging for smartphone: what it is and how it works

It is inconvenient to untangle the wires of a smartphone charger, to plug the plug into the connector. However, you can avoid this. Wireless chargers for phones and other gadgets are available. All you have to do is to put your smartphone to the device and it will charge. How does this technology work?

What is a wireless phone charger

A wireless charger for smartphones and other gadgets transmits electric current without connecting through a plug. It comes in many shapes and sizes. Usually, it is a small oval or rectangular shaped body with a wire. Inside it are the parts that enable wireless transmission of electricity. Such charging is even built into desks, car dashboards, and mouse pads.

How wireless phone charging works

The basis of the work of electricity transmission without wires is electromagnetic induction. Alternating current passes through a copper coil. It forms a magnetic field around itself. If a second coil is placed in the area of this field, an electric current is generated at the receiving coil. In wireless chargers, there is a main coil. It receives electricity from the building's or car's power grid through a wire. The second coil is installed in the smartphone. It receives current wirelessly from the charger coil.

The process of wireless charging is as follows:

• The charging station is plugged into the power grid and is in standby mode. When a phone or other device is brought closer to it than 4 cm, the charger goes into activity mode.
• In the background, the device emits a pulse every 0.4 seconds. The more energy accumulates in the smartphone, the more the voltage drops.
• When the phone's battery is completely full, the charger goes into background mode and the power supply stops.

Features of wireless phone charger

Wireless phone charger is very easy to use:

• The transmitting module is connected to the power grid.
• The charging station is installed in a convenient place: on the table, on the windowsill, on the car panel, if it is connected to the electrical system of the car.
• The smartphone is placed on the wireless device.

Not all gadgets can be charged with wireless technology. Electric current without wires is transmitted only through a plastic or glass case. If the smartphone has a metal casing, energy will flow through it. Some smartphones with aluminum cases have a polymer insert. Through it goes wireless charging.

It is important to take into account that the charging speed through wireless technology is slower than through classic wired charging. This disadvantage is not so noticeable for smartwatches or other gadgets with low battery capacity.

Wireless charging uses approximately twice as much energy as wired charging. Some of the energy escapes in the form of heat. A rise in temperature has a negative effect on the smartphone battery. It is therefore essential that the wireless charger and the smartphone have overheating protection. Some wireless chargers have a fan for cooling. However, it makes noise.

Not all smartphone users can take advantage of this technology. Often wireless charging is supported only in top models. It is not installed in budget phones.