ZHENGXI GROUP is an experienced Variable Transformers (referred to as “Variac” or “Variable Autotransformers”) specialist that is able to provide continuously adjustable AC voltages for laboratory equipment, industrial equipment, production equipment, and export machines.
Our variable transformers are made with high efficiency and with a lifetime guarantee to work with single-phase or three-phase, manual or motorized operation.
TSGC2 1.5Kva-30Kva 380V/430V Three Phase Manual Variable Transformer
The TSGC2 Series Three Phase Manual Variable Transformer is a high-performance adjustable autotransformer designed for precise voltage control in industrial and laboratory applications.
This series adopts an autotransformer structure with a toroidal coil and carbon brush mechanism. By manually rotating the carbon brush along the coil surface, users can smoothly adjust the output voltage from 0 to 430V, achieving accurate voltage regulation with minimal waveform distortion.
Compact in design yet powerful in performance, the TSGC2 variable transformer delivers high efficiency (>90%), stable operation, and long service life, making it an ideal choice for voltage testing, equipment calibration, and power control systems.
High-Quality Single Phase Adjustable Variac Transformer 0.5kVA-50KVA
The Single Phase Adjustable Variac Transformer (0.5kVA–50kVA) is a high-performance voltage control device designed for precise, continuous voltage regulation. As a leading variable transformer manufacturer, ZHENGXI provides reliable, efficient, and durable solutions suitable for laboratories, industrial machinery, testing systems, and lighting control applications.
This variac variable transformer adopts a toroidal autotransformer structure with a high-precision carbon brush and handwheel mechanism, ensuring smooth, stepless voltage adjustment from 0V to 250V. It features high efficiency, low waveform distortion, and long service life, offering stable voltage output and superior performance in demanding environments.
How a Variable Transformer Works
Variable Transformer Working Principle
A Variable Transformer is an electromagnetic induction device, like an ordinary transformer, except in one important way in terms of physical structure.
Its fundamental component is the presence of a winding in the form of a single continuous winding supported by a toroid-shaped magnetic core along with a moving carbon brush (also called a wiper. In this design, the wiper systematically overrides the winding as it moves along the winding. In the process, the wiper makes contacts along the winding as it systematically overrides the winding. This enables the output voltage to range linearly from 0% to 100% (and even 130%) of the incoming voltage."
Important Parts of a Variable Transformer
Toroidal Core – Provides low magnetic loss and a compact size
Copper Winding: Allows a voltage change
Carbon Brush / Sliding Contact: It allows voltage control.
Input & Output Terminals - Connect the Power Source & the Load
Protective Enclosure (Optional) – Improves operational safety
Variable Transformers come in single phase or three phase types and have power ratings from 500 VA to more than 100 kVA.
Advantages of Variable Transformer for Voltage Control
Why Use a Variable Transformer?
- Smooth & Continuous Voltage Adjustment：Designed for sensitive instruments and gentle power ramp-up
- High Efficiency：Much lower losses than in the resistive regulators
- Strong & Long Lasting：Copper windings of heavy-duty type and industrial-grade core.
- Cost-Effective Voltage Regulation：Removes the requirement for multiple fixed ratio transformers
- High Load Capability Suitable for both resistive & inductive loads
- Due to its benefits, the Variable Transformer is preferred in voltage simulation, aging tests on equipment, and quality inspection systems.
Industrial Applications of Variable Transformers
- Manufacturing & Production Lines
Voltage adjustment for motors, heaters, and industrial machines - Electrical & Calibration Laboratories
Precise voltage input for testing and R&D environments - Audio & Broadcast Equipment
Controlled power supply for amplifiers and sound systems - Renewable Energy Testing
Simulating grid voltage variations for solar and wind inverters - HVAC & Building Systems
Voltage tuning for fans, compressors, and control circuits
Their adaptability makes Variable Transformers suitable for both legacy equipment and modern power systems.
How to Use a Variable Transformer Safely
Best Practices for Variable Transformer Operation
- Do Not Overload
Always operate within rated current and VA limits - Ensure Proper Ventilation
Prevent overheating during continuous operation - Maintain the Carbon Brush
Regular cleaning reduces sparking and wear - Use Isolation Transformers When Required
Especially for sensitive or high-voltage testing - Monitor Output Voltage in Real Time
Use voltmeters or digital monitoring systems
Following these best practices significantly improves operational safety and equipment lifespan.
Variable Transformer vs Automatic Voltage Stabilizer
| Feature | Variable Transformer | Automatic Voltage Stabilizer |
|---|---|---|
| Voltage Adjustment | Manual | Automatic |
| Response Speed | Operator controlled | Instant |
| Output Stability | Depends on user | Fully regulated |
| Typical Use | Testing & labs | Continuous power protection |
👉 Tip: Variable Transformers are ideal for testing and adjustment, while stabilizers are better for long-term voltage protection.
FAQ
Q1: What is the purpose of a Variable Transformer?
A Variable Transformer is a device used to set and control the output of the AC voltage by hand.
Q2: Is a Variable Transformer equivalent to a Variac?
Variac” is a registered trademark, whereas the technical term is “Variable Transformer.
Q3: Can variable transformers handle a high current load?
Yes. These types of models are intended for high currents, continuous duty within rated specifications.
Q4: Are Variable Transformers safe for electronic testing?
Yes, if used correctly, they offer stable and variable voltages, which is apt for sensitive circuits.
Q5: Do Variable Transformers have protection functionality?
Some models feature thermal protection systems, circuit breakers, or fuses. These improve safety.
Conclusion
Even today, the Variable Transformer remains an essential component in the modern electrical setup, providing precise control over voltage, reliability, and ease of use. Its applications in the lab, industry, or testing labs make this tool indispensable for every engineer and tech professional.
For enterprises requiring effective voltage control, the use of the Variable Transformer, professionally made, will ensure optimal performance and efficiency in the long run.
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