Zhengzhou City, Henan Province, China
HOME » News » What is the role and principle of the isolation transformer

What is the role and principle of the isolation transformer

ZTELEC Insulation Materials | 18-10-22

First, why use isolation transformer
Why use an isolation transformer? When supplying power to a low-voltage user, the power supply system generally adopts a three-phase four-wire system. The neutral line is grounded, that is, the wires to the residents’ homes, one is the phase line (the fire line), and the other is the neutral line. It is in the same position as the earth. When the human body touches the hot bottom plate, it will cause current to flow through the human body and form a loop with the earth, causing electric shock hazard. If an isolation transformer is used, it will be safer because the primary and secondary exchange energy through the magnetic field, and there is no physical hard connection. Even if the human body touches the charged item, the potential of the charged part is due to the same position of the human body and the earth. Low potential, will not cause electric shock hazard.
isolation transformer
Second, the role of isolation transformer
The main function of the isolation transformer is to completely insulate the electrical of the primary side from the secondary side and also isolate the circuit. In addition, the high frequency loss of the iron core is utilized to suppress high frequency noise from being transmitted to the control loop. The isolation transformer is used to suspend the second ground to the ground, and can only be used in the case where the power supply range is small and the line is short. At this point, the system’s capacitance to ground capacitance is not small enough to cause personal injury. Another important role is to protect personal safety and isolate dangerous voltages.
The isolation transformer is a transformer that is electrically isolated from the input winding and the output winding. The isolation transformer is used to avoid accidental simultaneous contact with the charged body. The isolation of the transformer is to isolate the current of the original secondary winding around the coil. Early used in Europe for the power industry, power supply for control circuits, safety lighting and indicator lights for general circuits in the electronics industry or industrial and mining enterprises, machine tools and machinery.

Third, the principle of isolation transformer
The principle of an isolating transformer is the same as that of a normal transformer. They all use the principle of electromagnetic induction. Isolation transformers generally refer to 1:1 transformers. Because the secondary is not connected to the ground. There is no potential difference between any of the secondary lines and ground. Safe to use. Often used as a maintenance power source.
The isolation transformer is not all 1:1 transformer. The power supply that controls the transformer and tube equipment is also an isolation transformer. Power supplies such as tube amplifiers, tube radios, and oscilloscopes and lathe control transformers are isolation transformers. For example, a 1 to 1 isolation transformer is commonly used for safe maintenance of color TV sets. Isolation transformers are used more and are also used in air conditioners.
Generally, although there is an isolation circuit between the original and secondary windings of the transformer, in the case of a high frequency, the capacitance between the two windings still causes electrostatic interference between the circuits on both sides. In order to avoid such interference, the primary and secondary windings of the isolation transformer are generally placed on different cores to reduce the capacitance between the two; the original and the secondary windings are concentrically placed, but are placed between the windings. Electrostatic shielding for high immunity to interference.

At ZTELEC choose a safe isolation transformer that is responsible for safety.

Ztelec Group