Variable Auto Transformer,
Continuously Variable Transformer, Auto Transformer
We manufacture three-phase Variacs and Variable Auto Transformers designed specifically for laboratory applications and supplied in powder-coated metal sheet enclosures. All input and output connections are properly terminated on insulated terminals and clearly marked to ensure safe and easy wiring.
Single-phase and three-phase Variable Auto Transformers or Variacs manufactured in open execution are intended for installation inside control panels and testing equipment.
These Variacs are available in the following current ratings:
4 A, 5 A, 6 A, 8 A, 10 A, 15 A, 20 A, 28 A, 32 A, 40 A, 50 A, 60 A, 75 A, 100 A, 150 A, 200 A, and 250 A.
Higher ratings of up to 1800 Amps can also be supplied against specific customer requirements.
SALIENT FEATURES for
Dimmerstat / Variable Auto Transformers :
Continuously Variable Auto Transformers offer several operating advantages and conveniences over other manually operated AC voltage control devices. Some of the key features are outlined below:
Smooth Voltage Control
Variacs or dimmerstats can be set to any output voltage within their rated range. The output voltage is continuously adjustable from zero to maximum. Since the voltage difference between adjacent turns is small and the brush arm maintains constant contact with more than one turn, harmful sparking is avoided. This allows the output voltage to be adjusted smoothly and accurately, even to a fraction of a volt, by simple rotation of the control knob.
Low Operating Torque
A glass-smooth commutator, special sintered bushings for the shaft, and precise coil assembly result in very low operating torque for our Variable Auto Transformers.
Compact Size
Variable Auto Transformers are significantly smaller in size compared to other voltage control devices of equivalent ratings.
High Efficiency
These transformers have very low losses under all load conditions. Toroidal Variable Auto Transformers use low-loss, grain-oriented strip-wound cores. Careful copper selection and optimized design ensure minimal watt loss compared to other types of controllers.
No Waveform Distortion
Our Variacs deliver an output voltage waveform that is a clean, faithful, and distortion-free replica of the input voltage waveform.
Superior Voltage Regulation
The output voltage remains substantially independent of load. The voltage drop from no-load to full-load conditions is minimal.
Linear Output Voltage
The output voltage varies linearly with the angle of rotation of the control knob, allowing precise and predictable control.
Low Temperature Rise
Temperature rise is maintained below 50°C under continuous duty operation.
Advanced Design
Excellent electrical performance is combined with rugged and compact construction. Brush replacement is simple and convenient. Two, three, or more units can be mechanically ganged on a single shaft for series, parallel, or three-phase operation.
Long Operating Life
When used correctly, Variacs offer a long operating life comparable to that of standard fixed-ratio power transformers.
Rugged Construction
Designed for heavy-duty, trouble-free operation, all components are engineered to deliver maximum durability even under extreme operating conditions.
Low Magnetizing Current
By using high-quality grain-oriented silicon steel with adequate core cross-section, iron losses are minimized. The no-load current is typically less than 1% of the rated current.
Negligible Maintenance and Long, Trouble-Free Life
Variacs are designed to deliver reliable performance under normal working conditions with minimal maintenance. Routine care, such as timely replacement of carbon brushes and cleaning of the commutator surface to remove dust or foreign particles, ensures a long, uninterrupted, and maintenance-free operational life.
Variacs can also be supplied in enclosed models with additional features such as voltmeters, ammeters, fuses, switches, and pilot lamps. For remote control or automatic adjustment of output voltage, Variacs can be fitted with a motor drive. The motor is coupled to the central shaft, and as it rotates, the contact arm moves smoothly over the plated surface. These motors operate quietly on 240 V, 50 Hz single-phase AC, and their rotation can be reversed using a simple SPDT switch.
The precise design and assembly of the brush, which maintains constant pressure on a smoothly finished and securely bonded commutator surface, ensures excellent mechanical performance, long life, and low operating torque. Brush replacement is rarely needed, and when required, it is easily performed. High safety margins in terms of voltage, current-carrying capacity, and dielectric strength further contribute to the extended life of the unit.
SIMPLE INSTALLATION AND CONNECTION:
Mounting of units is convenient and easy. Most Series units are designed with an adjustable shaft to accommodate either bench or panel mount (adjustable to accommodate varying panel thickness). Terminals are easily accessible; screw, lug or solder design. Connections deliver increasing output voltage with either clockwise or counter-clockwise knob rotation. Manually operated units have standard dials graduated 0-100% or 0-270V (output voltage).
We can also provide you DC & AC Auto Transformers or DC Variacs, DC Dimmerstat with option of DC and AC output. We also provide additional features like MCCB, Motorized Operation, Remote Extension etc.
Customer Service & Quality
Our products are all made in India
As part of our engineering and manufacturing services, we help our customers customize scheduling, packaging, shipping, billing, and communication processes to meet their specific inventory management, product handling, and delivery requirements. We are committed to delivering a level of quality and service that enables our customers to become leaders in their respective markets. We take pride in being the only transformer company our customers need. Driven by a spirit of unity, selflessness, and single-minded focus, we provide customer service that truly stands out.
Countries Where
We are Regularly Exporting
- 🇮🇳 Gurgaon
- 🇿🇦 South Africa
- 🇲🇼 Malawi
- 🇲🇿 Mozambique
- 🇲🇬 Madagascar
- 🇳🇬 Nigeria
- 🇿🇼 Zimbabwe
- 🇰🇪 Kenya
- 🇬🇭 Ghana
- 🇹🇿 Tanzania
- 🇺🇬 Uganda
Our Happy Customers
We were looking for some high quality and reliable DC to AC inverter for commercial use for our appliances. My verdict is that the products were of excellent quality and support from the Purvolt was professional. Product pricing was also reasonable. Highly recommended. Kudos to the team.
– Ankita, Faridabad, India
I am one of the oldest clients of Purevolt India and what i like about is communication and product quality as promised over the call. I couldn't thank more to the Sumit for meeting our expectations. The quality of the product was satisfactory, it met our requirements, and it was delivered on time, as promised by the team.
Our factory required some DC to AV inverter. I must say that the product quality was beyond our expectations. I couldn't thank more to the Purevolt Team for delivering high quality product. Communication with team was also smooth. The team has done an excellent job managing delivering process.