Do you know the difference between these transformers?

Release time:

2023-10-30

The difference between high frequency transformer and low frequency transformer?

Isolation Characteristics Description

Assuming that the transformer T1 in the circuit is a 1:1 transformer, that is, when 220V AC voltage is input to it, its output voltage is 220V, but it should be noted that the 220V voltage output by the transformer refers to the voltage between the two ends of the secondary winding, that is, the voltage between the 3 and 4 ends.

The voltage between either end of the secondary winding (e. g., 3) and the ground terminal is 0V, because the output voltage of the secondary winding does not take the ground as the reference terminal, but takes the other end of the secondary winding as the reference point, and the primary and secondary windings are highly insulated.

In this way, people standing on the ground only contact with either end of the secondary winding of transformer T1, and there is no danger of life (must not contact the ends of secondary windings 3 and 4 at the same time). If they contact the phase end of the primary winding, they will get an electric shock. This is the isolation of the transformer.

Isolation function of power transformer
AC 220V is used as a power supply in many electronic appliances. In order to ensure the personal safety of users during the use of the equipment, 220V AC power supply needs to be isolated. At this time, a power transformer is used.

At the same time, the power transformer reduces the 220V AC voltage to a suitable voltage.

In troubleshooting, it is often necessary to contact the components in the circuit or the ground wire in the circuit in the energized state. After joining the power transformer can prevent the risk of electric shock.

Summary: Characteristics of isolation transformers at the input of AC power supply

If the third harmonic and interference signal of the power grid are serious, the isolation transformer can be used to remove the third harmonic and reduce the interference signal.

The use of isolation transformer can produce a new neutral line to avoid abnormal operation of equipment due to poor neutral line of the power grid.

Current waveform distortions (e. g., third harmonics) caused by non-linear loads can be isolated without contaminating the grid.

The characteristics of the isolation transformer at the output of the AC power supply:

To prevent the current distortion of the nonlinear load from affecting the normal operation of the AC power supply and pollution to the power grid, it plays a role in purifying the power grid.

Sampling at the input of the isolation transformer, so that the distortion of the nonlinear load current does not affect the accuracy of the sampling, and the control signal that can reflect the actual situation is obtained.

If the load is unbalanced, it will not affect the normal operation of the regulated power supply.