Wireless phone chargers, also known as wireless charging pads or wireless charging stations, work on the principle of electromagnetic induction to transfer power from the charger to the phone without the need for physical connectors like charging cables.
Transmitter (Charging Pad): The wireless charger, or transmitter, contains a coil of wire, typically made of copper, which is connected to a power source. When you plug the charger into an electrical outlet, it generates an alternating current (AC) through this coil.
Receiver (Phone): Your phone also has a coil inside, which is usually located on the back of the device or under the back cover. This coil is connected to the phone's battery and charging circuit.
Electromagnetic Field: When the charger is connected to power, it generates an electromagnetic field around the coil. This field is created by the alternating current running through the coil. The coil in the phone also interacts with this electromagnetic field.
Induction: According to Faraday's law of electromagnetic induction, a change in the magnetic field around a coil of wire induces an electromotive force (EMF) or voltage in the wire. In the case of wireless charging, the changing magnetic field in the charger's coil induces a voltage in the coil inside the phone.
Conversion: The induced voltage in the phone's coil is then converted from AC to DC using a rectifier circuit. This DC power is used to charge the phone's battery or power the device, depending on whether it's connected to a power source or not.
Charging: As long as the phone's coil remains within the range of the charger's electromagnetic field, power will be transferred from the charger to the phone. When the phone's battery is fully charged or is removed from the charger, the charging process stops.
For wireless charging to work, both the charger (transmitter) and the phone (receiver) must support the same wireless charging standard, such as Qi, which is a widely adopted standard for wireless charging in various devices. Compatibility between the charger and the device is crucial for successful wireless charging. When you place your phone on a compatible wireless charger, the electromagnetic induction process begins, and your phone starts charging without the need for physical connections.
