Isolation Transformers

What is an Isolation Transformer?

A transformer is a static electrical device which transfers power from one voltage level to another while keeping the frequency same. And, if the primary and secondary windings are coupled through a common iron core, they are considered as the Isolation Transformer. The secondary winding, as usual in transformers, is physically and electrically isolated from the primary winding. There is no literal electrical link between the two windings. They are magnetically coupled, not electrically linked.

This “line isolation” is a very desirable characteristic for various applications. As there is no electrical connection between the load and source, the transformer behaves like a filter between the two windings by segregating them from each other. The Isolation Transformers significantly block the voltage spikes, switching transients and noise that originate in the supply side from being getting transferred to the load side. Some isolation transformers are built with a turn ratio of 1:1. Such transformers are exclusively built to have the same input and output voltage and are used for isolation only. All transformers except autotransformers provide isolation. When used with a switching power supply, an Isolation Transformer prevents higher-order harmonic signals from degrading the performance of adjoining circuitry. It is especially crucial in computers or other equipment incorporating microprocessors. Improper isolation can cause interference to other functions of the system and can cause excess ripples at the output voltage waveform.

What are the Benefits of Isolation transformers?

The Isolation Transformers have numerous benefits as-

• Protection of the users from the faulty equipment.
• To have safe, reliable and accurate measurements.
• To avoid ground loops.
• To physically isolate/separate some part of an electrical system from the other or rest of the system.
• On drives, they help to filter the electrical noise caused by SCR’s.