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All You Need To Know About Auto Variable Transformers

by | Apr 24, 2019 | Business

Variable voltage autotransformers are popularly known as Variac

Variable voltage autotransformers are transformers with a single coil, in which the same coil is used as the primary and secondary windings.


In a regular transformer, there are two windings, known as the primary and the secondary windings. The primary windings are meant to receive voltage from the source and secondary windings function to transfer to the output load. But in variable voltage autotransformers, there is only a single winding that works as dual-coil windings. As a result, voltage inputs variations are either decreased or improved automatically with the help of this single winding.

Simply put, it Variac changes the voltages that enter it according to the desired convenience


Variable voltage autotransformers are of the same purpose and use as that of any regular transformers; to have the voltages that enter it to be raised or lowered. but unlike regular transformers, Variac does not have high voltage applications.

Variac is used in industrial equipment, induction motors, to control externally dependent switches. It can also be used as an alternative to the regular transformers as they are inexpensive & lighter.

Most commonly, they are used to control speed and as lights dimmer. There are plenty of Variac transformer manufacturers that market them.

Variable voltage auto transformers V/S regular transformers-


  1. Their core is smaller as compared to the regular transformers and hence require fewer windings ( apt for smaller applications)
  2.  Variac transformers in India & globally, are automated, hence it can change voltages quickly
  3. They are lighter, inexpensive and efficient


  1. They do not have high voltage applications
  2. Unlike the regular transformers, electrical insulation between the windings is not provided for. This poses a safety threat.

Variac is easily available in the market. Many leading Variac transformer manufacturers are offering its customers specialised and customised specifications. Variac transformer in India is often priced at competitive rates listed on different platforms by variable autotransformer manufacturers.

Variac transformers in India comes in multiple phases and price list, for example, 3 phase Variac transformers in India starts from INR 4000 per unit. Single phase Variac transformer in India is also available which are marketed by leading variable autotransformer manufacturers and are priced a little less than the phase 3 ones.

Consider these factors before purchasing a Variac transformer:

  1. Unflawed quality
  2. Durability
  3. Operational fluency
  4. Reasonability
  5. Customised offerings.

Do browse through the net to shortlist some of the best variable autotransformer manufacturers. Most of these Variac transformer manufacturers have listed themselves on the internet, it is also crucial to read a few articles and reviews about them before taking any decision.

Additionally, off-line enquires about the variable autotransformer manufacturers could also help.

Depending on your needs, most of the best Variac transformer manufacturer will be able to provide you products with in-depth specifications and customisations.