What is Auto Transformer?

Auto Transformer Circuit

Auto Transformer is a rated product and it has been reviewed by Amazon customers. Amazon customers gave Auto Transformer an average of 3.8 stars out of 5.

An autotransformer is a device that does not require power to function and can convert voltage from one level to another as an electrical load, such as an electric motor or light bulb, is turned on or off. Its purpose is to reduce the voltage for household electric appliances such as lamps and televisions that can be damaged by high voltage coming from the power company’s lines.

Autotransformer Models

There are two models of Auto-transformer, the 600VA (Volts Amperage) and 1200VA (Volts Amperage). The 600VA model is used to convert a 240-volt source to a more usable 120-volt source. The 1200VA model is used to convert between a 120-volt source and its halved form, i.e., a grounded household outlet from a grounded GFCI receptacle.

The 600VA model is rated for a constant voltage of 600 volts, which means there is no load on the system. The 1200VA model supplies up to maximum 120-volt output and works at voltage drops of up to 120 volts, so it can work with loads such as light bulbs and motors. The transformer is connected to a receptacle with the neutral wire grounded. If the voltage source is grounded, grounded neutrals are required to be connected to the transformer’s neutral output. The apparatus operates in two modes: either continuous operation or short-circuit protection.

The transformer’s rated output is equal to its input power divided by 0.65 when in continuous operation mode and its input power divided by 0.9 when in short-circuit protection mode (120 volts × 0.9 = 120/0.65 = 1200 watts).