Variac transformer or Variable Auto Transformer.
A variac transformer comes with a single-coil, where two different pieces of the same coil are available as primary coil and secondary coil. There are single-phase and three-phase variac available in the market. These dimmer transformers cater to some specific applications. As an option, users can opt for the manual or motorized device. In this article, we will discuss its types, applications, prices, and advantages. Let’s explore it.
What is an variac auto transformer?
There are no differences between the two when it comes to purpose. The objective of both devices is There is only one single voltage winding in an auto transformer, which is shared by both sides. It is often referred to as variac dimmer. This single winding is “tapped” along its length to provide a proportion of the primary voltage supply to the secondary load. The variable auto transformer has a magnetic core but just one winding shared by the primary and secondary circuits.
As a result, the main and secondary windings of an autotransformer are magnetically connected. The main benefit of this variac transformer design is that it can be produced much lower price for the same VA rating. Still, the main downside is that it lacks the primary/secondary winding isolation of a traditional double wound transformer. However, three-phase variac autotransformers are costly.
The primary segment of the winding is connected to the AC power supply, with the secondary winding being a component of this primary winding. An autotransformer may also be used to scale the supply voltage up or down by inverting the connections. The secondary voltage is “stepped-down” if the primary is the whole winding and is linked to a supply, while the secondary circuit is only connected across a winding section. Once you understood the auto-transformer, it is easy to understand a variac transformer.
What a variac transformer does?
Variac, or Variable Auto Transformers, are devices that allow for constant regulation of AC output voltages. These Variable Auto Transformers produce a distortion-free output, making them ideal for testing delicate electrical appliances or equipment. These variable transformers have been built with cutting-edge technology to provide a regulated linear adjustment of output voltages.
VARIAC is a variable voltage auto transformer with a moveable carbon tip mounted to a brush-arm sliding on silver plated commutates. The brush-arm is rotated manually or by a motor drive that produces an output voltage ranging from zero to above line voltage.
Types of variable auto transformers.
Based on its mode of operation, there are two main types of variac transformers.
Manual variac.
In a manual Variac transformer, you can see dimmers in a single phase and three phases. Therefore, you can use them for numerous applications. The usual output range is up to 270V in a single phase, increasing up to 470V in three phase variac.
Motorized variac transformer.
There is a motor to control the functionality of this type of unit. You can install and control the functionality of these transformers easily. Due to the same reason, they can accommodate a large volume of power. They provide a high level of flexibility as well.
Applications of Variac transformers.
A variable autotransformer is useful at the time of boosting low lines and making supply voltage adjustments. When you want to conduct overvoltage testing and under-voltage testing, you can use these transformers. Moreover, they are useful at the time of testing watt meters, voltmeters, and ammeters. Some places where you can see these transformers include photography studios, restaurants, and theatres.
