How the on board charger works

Chargers have become an indispensable part of our daily routine, enabling us to recharge our electronic devices like smartphones, laptops, and tablets. But have you ever pondered over the mechanics of chargers? In this article, we will delve into the scientific principles behind chargers and how they operate.

To begin with, chargers function on the principle of electromagnetic induction, which states that when a conductor moves through a magnetic field, an electric current is induced in the conductor. This is the same principle that powers generators and motors.

Now, let's take a closer look at the components that make up an on board charger. A typical charger comprises two vital elements, namely, a transformer and a rectifier. The transformer's role is to convert the high voltage from the power outlet to a lower voltage suitable for charging the device, while the rectifier transforms the AC (alternating current) voltage to DC (direct current).

The transformer uses two coils of wire wrapped around a magnetic core. The primary coil, connected to the power outlet, generates an alternating current that produces a magnetic field. This magnetic field, in turn, induces a current in the secondary coil, which is linked to the device being charged. The ratio of the number of turns in the primary and secondary coils determines the voltage induced in the secondary coil.

The rectifier, which is typically composed of diodes, converts the AC voltage of the transformer into DC voltage. Diodes are electronic devices that allow electricity to move in only one direction. Since the AC voltage of the transformer oscillates between negative and positive, the diodes ensure that only positive power flows to the device being charged, resulting in a steady DC voltage suitable for charging.

It is worth noting that some on board chargers​, particularly fast chargers, may include additional components like capacitors or voltage regulators. Capacitors store power and discharge it rapidly, enabling the charger to supply the power required to charge the device. Voltage regulators, on the other hand, ensure that the charger's output voltage remains constant, even when the voltage input fluctuates.

In summary, chargers work on the concept of electromagnetic induction. The transformer reduces the high voltage from the power outlet, while the rectifier converts AC voltage into DC. The diodes in the rectifier ensure that only positive power is transmitted to the device being charged, resulting in a steady DC voltage. Some chargers may include additional components like voltage regulators or capacitors to improve their efficiency. Understanding how chargers work helps us appreciate the technology behind our electronic devices.