Isolation transformers also named safety transformers, and are widely used in medical equipment, automatic control equipment, home appliance speaker equipment, security monitoring equipment, etc.
What is the funtion of isolation transformer:
The isolation transformer completely insulates the electrical on the primary side (primary winding) and the secondary side (secondary winding) and also isolates the loop. In addition, it takes advantage of its high-frequency loss of iron to prevent high-frequency clutter from entering the control loop and interfering with loop equipment. The isolation transformer is used to suspend the secondary to the ground, which can only be used in the occasions with a small and short power supply range. At this time, the capacitance current to the ground of the system is too small to cause personal injury, it is a safe power supply!
What is the nature of isolation transformer:
Isolation transformers are safe power supplies and are generally used for machine maintenance, protection, lightning protection, and filtering. The isolation transformer is usually a 1:1 transformer. Primary single-phase 220V, secondary is also single-phase 220V; or primary three-phase 380V, secondary energy is also three-phase 380V. First of all, we usually use one line of AC power voltage to connect to the ground, and there is a 220V potential difference between the other line and the ground. Human contact can cause electric shock. The secondary difference of the isolation transformer is not connected to the ground, and there is no potential between any two wires of it and the ground. People will not get an electric shock if they touch any line, so it is safer. Secondly, the output terminal of the isolation transformer is completely "open circuit" isolated from the input terminal, so that the input terminal of the transformer (the power supply voltage supplied by the grid) can effectively play a good filtering role. So as to provide a pure power supply voltage to the electrical equipment.
What is the principle of isolation transformer:
The principle of the isolation transformer is the same as the ordinary principle. All use the principle of electromagnetic induction. The isolation transformer generally refers to a 1:1 transformer. Because the secondary is not connected to the ground. There is no potential difference between any secondary line and ground. It is safe to use and is often used as a maintenance power supply. Isolation transformers are not all 1:1 transformers. The power supply for the control transformer and electronic tube equipment is also an isolation transformer. Power supplies such as tube amplifiers, tube radios, oscilloscopes and lathe control transformers are all isolation transformers. Generally, although the primary and secondary winding of the transformer also have the function of isolating circuits, in the case of higher frequencies, the capacitance between the two winding will still cause electrostatic interference between the two circuits. In order to avoid this interference, the primary and secondary winding of the isolation transformer are generally placed on different core legs to reduce the capacitance between the two. Some are placed by the primary and secondary winding, but electrical shielding is added between the winding , In order to obtain high anti-interference characteristics.