How does a transformer increase voltage and decrease current?
Time：2024-12-14 Auther：ZTelec-www.ztelectransformer.com
Principle of transformer electromagnetic induction
A transformer is a device that uses electromagnetic induction to transmit electrical energy. The transformer consists of two coils, namely the input coil and the output coil. The input coil is also called the original coil, and the output coil is also called the secondary coil. The transformer works by using the current in the input coil to create a magnetic field. The magnetic field is able to penetrate the input and output coils to create an electromotive force in the output coil. When the output coil is attached to a load, the output current is generated, which enables the transfer of electrical energy from the input to the output.
The working principle of the transformer
The transformer works on the principle of electromagnetic induction. The input side coil is connected to the power supply to generate an alternating magnetic field. The alternating magnetic field is transmitted through the iron core to the output side coil to generate an induced electromotive force on the output side. Since the change of the magnetic field is proportional to the number of turns of the coil, the output voltage and current can be adjusted by changing the ratio of turns of the coil.
An increase in voltage and a decrease in current
The transformer realizes the voltage transformation by adjusting the ratio of turns between the primary winding and the secondary winding. The ratio of turns refers to the ratio of the number of turns of the primary winding and the secondary winding. And the number of turns of the primary winding and the secondary winding is usually expressed by N1 and N2 respectively.
Voltage increase
When the number of turns N2 of the secondary winding is more than the number of turns N1 of the primary winding, the transformer realizes the boost function. This is because the ratio of the induced electromotive force E2 in the secondary winding and the electromotive force E1 in the primary winding is equal to the ratio of the number of turns in the two windings according to the principle of electromagnetic induction, that is, E2/E1=N2/N1. Since N2>N1, E2>E1, that is, the output voltage is higher than the input voltage. And the voltage boost is achieved.
In the boost process, since the input power is equal to the output power (ideally, without considering the loss), the current will be reduced accordingly to maintain the balance of power when the output voltage is increased. This is because in the case of a certain power, voltage and current are inversely proportional.
Reduction of current
The reduction of current is an inevitable result of the step-up process. In a transformer, magnetic energy is transferred from the primary winding to the secondary winding. According to Lenz’s law of electromagnetic induction, the secondary magnetic field always blocks the change of the primary magnetic field. Therefore, as the number of turns in the secondary winding increases, the current required in the secondary winding decreases in order to produce the same rate of flux change as the primary magnetic field.
In addition, from the point of view of energy conservation, the transformer converts the input power to the output power during the boost process. Since the input power is equal to the output power and the voltage rises, the current must be reduced to maintain the balance of power. This is also the basic principle of the transformer to reduce the current during the voltage boost process.
