How the isolation transformers significantly reduce voltage spikes?

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 Transformers.

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

How the isolation transformers significantly reduce voltage spikes?

The isolation transformers significantly reduce the voltage spikes before reaching the secondary windings because of the rising time of current through an inductor.

We know,

The current in an inductor rises at an exponential rate.

As the current increases –> the expanding magnetic field cuts through the conductors of the coil and induces a voltage that is opposed to the applied voltage (by virtue of Faraday’s law of electromagnetic induction and Lenz’s law)

The amount of induced voltage e α L * ( di/dt) is proportional to the rate of change in current.

The faster the current tends to rise, the higher will be the opposition to the sudden change in current.

Spike voltages and currents are usually of a very short period, and they rise very rapidly. Such a surge causes the opposition to the change also to increase that rapidly. 

Therefore, in case an inductor is introduced in between the circuit the time taken by the spike to reach the secondary winding will significantly increase, and in the meantime spike will get considerably reduced or could be even completely eliminated.

We, Servostar is an established and renowned manufacturer based out of India and is catering to entire pan India in power equipment like Servo Stabilizers and all type of transformers including isolation transformers for domestic households and other industrial applications. We have a proven track record of supplying quality transformers and voltage stabilizers to various industries, commercial setups, residences, and the utility. We do provide consultancies services and customized transformers too.