Principle and structural analysis of isolation transformer

1、 Working principle
Fundamentals of Electromagnetic Induction
The isolation transformer is based on Faraday's law of electromagnetic induction, which induces an electromotive force in the secondary winding through the alternating magnetic field generated by alternating current in the primary winding, achieving electrical energy transmission.

Electrical isolation characteristics
There is no direct electrical connection between the primary and secondary windings, only magnetic field coupling is used to block the DC path and common mode interference conduction, ensuring the independence of the input/output circuit. Although there is a phase difference and a small potential difference between the secondary line and the ground, a single line contact cannot form a current loop to avoid the risk of electric shock.

Ability to suppress interference
By using high insulation materials and electromagnetic isolation design, the interference signals such as voltage spikes and noise at the input end are effectively blocked from affecting the output end equipment.

Voltage conversion function
By adjusting the winding turns ratio, voltage can be increased or decreased, but most application scenarios use a 1:1 ratio to maintain voltage stability
2、 Core structure
Iron core
Made of high permeability silicon steel sheets or ferrites, used to enhance magnetic coupling efficiency and reduce energy loss.

Winding

Primary winding: connected to an input power source, generating an alternating magnetic field through alternating current;
Secondary winding: Induced magnetic field generates output voltage, completely isolated from the primary winding.
Insulation system
Multiple layers of insulation materials (such as insulation paint and insulation paper) are used to wrap the winding, ensuring an electrical isolation strength of 45 between the coils and between the coils and the iron core.

Shell and heat dissipation
Metal or engineering plastic shells protect internal components, and some models are equipped with heat sinks or cooling systems (such as oil immersed) to maintain operating temperature.

3、 Typical applications
Safety protection: used in scenarios such as machine tools and medical equipment to prevent electric shock to personnel;
Interference suppression: protects precision electronic equipment (such as oscilloscopes, communication systems) from power interference;
Voltage adaptation: matching different device voltage requirements in industrial control systems