Now some smartphones no longer need cables to charge. Palm was the first company to introduce wireless charging via Touchstone Wireless Charging Dock in 2009. Since then, hundreds of devices from Microsoft Lumia 930 to Samsung Galaxy S6 come with wireless charging capabilities. There are two types of commonly used wireless charging technologies: Inductive and Resonance.
Inductive electromagnetic filling works by using electromagnetic space to move energy between two objects: charging plate and device. The charging plate is connected to the power supply, with cable coils inside. When an electric current flows through a cable, a magnetic space is created around the cable. The cable coil strengthens the magnetic space – the more coils on the coil, the larger the magnetic space. The device will also be equipped with a smaller coil cable. Electricity is generated when the cable is placed on the magnetic space generated by the charging plate. The electricity generated can be changed using simple electrical components to produce a stable power supply so that it can charge the battery. The limitation of this method is the filler coil and the receiver must be adjacent, due to the narrow magnetic space. Most smartphones with wireless charging use this method.
In 2007, the team at MIT reported the discovery of an efficient way to move power wirelessly between spools spaced several meters apart. The team explained that the spacing between coils can be extended by adding a similar resonance. Resonance is the specific frequency generated by the natural vibrations of a particular object. The resonant frequency causes the wine glass to vibrate and even break when a certain tone frequency is played next to it. The MIT team found that induction may occur if both filler and receiver coils use the same resonant. With this principle, the MIT team was able to power the bulb up to two meters from the coil. Resonance charging on smartphones is the same principle and can extend the range of wireless charging. Allows resonance of charging plate through the table or another solid object. This additional range can also fill multiple devices with the same resonant frequency simultaneously. Resonance charging is a new technology but is expected to replace induction charging in a few years.
Advantages and Disadvantages of Wireless Charging
No need to connect USB cables and plugs to the smartphone, so it’s faster.
Avoid from USB connector damage because it is often used to charge the battery.
More efficient charger cable due to mini USB damage at the charging.
Practical because it can stop charging when the smartphone sounds by simply distance from the charger and recharge the battery after finished using the smartphone, especially on the type of Lithium battery.
Can be placed in various public places such as Airport, Cafe, Restaurant and public mall without the need to provide various kinds of chargers with different plugs for each brand.
The wireless charger is not as efficient as a cable charger in terms of efficiency. The time required, compared directly to charge with the cable, for now, wireless charging is still relatively long.
The use of electricity is also greater than the use of cable types. This is because part of the energy is converted to heat.
This type of charger also has a slightly more expensive price because it relies on technology that is more complicated than the general charger.
Wireless Charger makes your phone or smartphone look thicker and heavier than a regular charger. The charger unit is generally placed behind a thicker casing, making the smartphone feel thicker and heavier.
Despite the name of wireless charging, it does not mean this technology can easily charge the smartphone battery with any wireless or Wi-Fi signal available just like when accessing via a hotspot in a cafe or office.
This technology requires additional tools that are usually in the form of a dock or plate connected to an electric current.
Not all smartphones can charge the battery by using a wireless charging tool because there must be a hardware in the form of receivers in the smartphone.