A Variable Transformer, also known as a Variac or Auto Variable Transformer, is a device used to continuously adjust AC output voltage from zero up to rated or higher voltage without changing the frequency. It operates on the auto-transformer principle, using a single winding with a sliding carbon brush to provide smooth and stepless voltage variation.
Variable transformers are widely used in testing, laboratories, manufacturing, maintenance, and R&D applications where accurate voltage control is required. Built with high-quality copper windings and low-loss laminated cores, they deliver stable output, high efficiency, and long service life.
Quality assurance is deeply integrated into our manufacturing process. From raw material procurement to final performance validation, each isolation transformer undergoes rigorous inspection and testing to ensure superior reliability and durability.
Our comprehensive quality control protocols include:
Material Testing
Ensuring all core materials, windings, and insulation components meet stringent industry and safety standards.
Load Testing
Verifying efficient and stable transformer operation under full-load and overload conditions.
Thermal Performance Analysis
Monitoring temperature rise, insulation integrity, and cooling effectiveness for safe long-term operation.
Certification & Compliance
All products comply with ISO 9001:2015, CE, and RoHS standards, ensuring international quality, safety, and environmental complianc
One of the biggest advantages of a variable transformer is its ability to provide continuous and stepless voltage variation
Variable transformers operate on the auto-transformer principle, using a single winding for both input and output.
Because they require fewer windings and less magnetic material compared to isolation transformers, variable transformers are smaller, lighter, and easier to install.
These transformers are extremely easy to operate. Voltage adjustment is done through a simple rotary knob or an optional motorized control system
| Parameter | Specification / Description |
|---|---|
| Transformer Type | Variable / Auto Variable Transformer |
| Phase | Single Phase / Three Phase |
| Rated Capacity | 0.5 kVA to 500 kVA |
| Input Voltage | 230V / 415V |
| Output Voltage Range | 0 – 230V / 0 – 415V / 0 – 470V |
| Frequency | 50 Hz / 60 Hz |
| Winding Material | Electrolytic grade copper |
| Core Material | CRGO laminated core |
| Insulation Class | Class B / Class F |
| Cooling Method | Air Natural (AN) |
| Efficiency | High efficiency, low losses |
| Control Type | Manual / Motorized (optional) |
| Duty Cycle | Continuous |
| Mounting | Tabletop / Floor mounted |
| Standards | IS / IEC / ISO 9001:2015 |
