Variac or variable auto transformer manufactured by Servokon is available with AC control voltage controls that offer continuous AC voltage supply. Variac ensures a distortion free output that is suitable for sensitive electronic appliances and equipments in residential areas and industries. Manufactured with cutting-edge technology, these auto transformers ensure a consistent linear regulation of AC voltage to provide high output and negligible waveform distortion. It is suitable way of controlling current, light, heat and motor speed with a voltage factor. This transformer finds its wide applications in Auditorium, hotels, conference hall, laboratories, College & universities, Welding equipments, Servo stabilizer, rectifiers, battery charger and Testing instruments.
Construction
There is a single layer winding on toroidal core of high-grade cold rolled grain oriented (CRGO) steel
A contact arm with a carbon brush is fitted on the centre shaft
A special durable contact surface is made on one side of the copper winding and a specially finished carbon brush slide smoothly on the surface
As the control knob is rotated, the carbon brush slides over the winding
Features
These step-up and step-down transformers are widely used for:
Can enhance the output voltage in excess of twice the input voltage
Low temperature rise
Any desired voltage within the maximum range can be obtained by adjusting the carbon brush
Wide assortment of current rating 4 Amp. To 1200 Amp
Calibrated dial show approximately output voltage at no load
Spare carbon brushes provided up to 28 Amp
The contact arm can be moved both manually and by motor
High quality carbon brush
Delivers an output voltage from 0 to above line voltage
Step-less voltage control
Constructed with 99.9% pure copper
Short time overload capacity
High grade CRGO steel is used for constructing coils
Maintenance cost
Application
Auditorium, hotels, conference hall, laboratories etc.
Testing instruments
Servo stabilizer, rectifiers, battery charger
College & universities
Welding equipments
Precision Voltage Regulation for Industrial and Laboratory ApplicationsEngineered with a wide input voltage capacity and advanced insulation (Class B/F), these variable auto transformers deliver consistent and reliable voltage control for sensitive equipment. The copper silver-plated contacts and toroidal coil structure ensure reduced load loss and extended service life, making them ideal for labs, testing, and manufacturing processes.
Versatile Installation and Durable ConstructionChoose flexible mounting options including bench, panel, or floor installations. The robust powder-coated metal enclosure and natural cooling design make these transformers highly durable, even in demanding indoor environments with up to 90% relative humidity.
Safe and Efficient PerformanceOptional overload protection, negligible waveform distortion, and over 98% efficiency guarantee safety and performance. Every unit meets IS 5142 standards and features air/natural cooling for optimal longevity and reliability, providing peace of mind where continuous, stable output is crucial.
FAQ's of Variable Auto Transformers:
Q: How does a variable auto transformer provide precise voltage regulation?
A: A variable auto transformer utilizes a rotary knob or hand wheel to adjust the output voltage smoothly across the range, from 0 up to 270V (single phase) or 470V (three phase). Its toroidal coil structure with copper winding ensures minimal waveform distortion and stable, accurate voltage supply for sensitive industrial or laboratory equipment.
Q: What environments are best suited for installing these transformers?
A: These transformers are engineered for indoor environments such as laboratories and industrial setups. They can function reliably at temperatures ranging from -10C to 50C and with ambient humidity up to 90% RH. Flexible mounting options-bench, panel, or floor-add to their application versatility.
Q: When should overload protection be considered with these transformers?
A: While the transformers inherently offer high efficiency and continuous duty operation, overload protection is optional for safeguarding sensitive devices against sudden current surges or excessive loads. It's particularly recommended in setups where electrical loads may vary or unpredictable spikes may occur.
Q: What are the main benefits of choosing transformers with copper silver-plated contacts and powder-coated metal enclosures?
A: Copper silver-plated contacts reduce electrical resistance and heat buildup, enhancing current conduction and lifespan. The powder-coated metal enclosure offers improved mechanical durability and corrosion resistance, protecting against harsh indoor conditions and ensuring longevity.
Q: Where are these variable auto transformers manufactured and exported from?
A: These units are manufactured and supplied in India by trusted industry exporters and manufacturers adhering to IS 5142 standards, ensuring global compatibility and top-level electrical safety for diverse applications.
Q: What is the process for controlling output voltage?
A: Users adjust the desired output voltage manually using the rotary knob or hand wheel. This direct manual control mechanism allows fine gradation throughout the transformer's voltage range, giving immediate and precise adjustments as needed for different appliances or testing protocols.
