Product Range
Variable Transformer (Variac) Models We Build
American Style Variac 500VACompact variac for labs and repair benches, 0-260V dial.
American Style Variac 1KVA1KVA adjustable variac for testing and calibration.
American Style Variac 2KVA2KVA variac with smooth 0-260V output for workshops.
American Style Variac 3000VA3KVA heavy-duty variac for industrial test setups.
TDGC3-500W Variable Transformer500W single phase digital variac with LCD, 0-300V adjustable output.TDGC2J-1KVA Digital Variable Transformer1000VA with LCD voltmeter, 0-300V output.
TSGC2-3KVA Three Phase Variable Transformer3000VA three phase variac, 0-430V adjustable.TSGC2-6KVA Three Phase Variable Transformer6000VA three phase variac for industrial motor testing.
TDGC2 AC Single Phase Variable Transformer500VA-30KVA contact type manual voltage regulator, 220V to 0-250V.
A variable transformer — a variac, as most buyers call it — does one thing no fixed transformer can: it lets you dial the output voltage to any value between zero and 260V and hold it there. Turn the knob, watch the meter, stop where you need to. Laboratories use them to test power supplies, workshops use them to soft-start motors, plating shops use them to control a bath heater, and repair benches use them to bring old equipment up slowly. That single ability is why the variac has stayed in production for almost a century.
Overview
What This Series Does
A variable transformer (variac) provides continuously adjustable AC output voltage from 0 to 260V single phase, or 0 to 430V three phase. Because the output is tapped directly off a toroidal winding by a carbon brush, the waveform stays a clean sine wave — no chopping, no switching noise, no stepped output like you get from a cheap electronic regulator. That is what makes a variac suitable for calibration work and for equipment that is sensitive to a distorted supply.
Used in laboratories and universities, on equipment test and repair benches, for motor testing and soft-start, and in plating, heating and lamp-testing applications worldwide.
Specifications
Key Specifications
| Output Range | 0–260V or 0–130V (single phase) / 0–430V (three phase) |
| Capacity | 500VA – 30KVA single phase / 3KVA – 30KVA three phase |
| Frequency | 50Hz / 60Hz |
| Display | Analog voltmeter or digital LCD (voltage + current) |
| Output Waveform | Pure sine wave, stepless adjustment |
| Cooling | Natural convection; fan-assisted on larger ratings |
| Socket Standard | US style as standard; EU / UK / AU or bare terminals on request |
| Warranty | 12 months from delivery |
How a Variac is different
Unlike a fixed transformer with one output, a variac has a carbon brush that rides along the exposed winding. As you turn the knob, the brush taps the winding at a different point and the output voltage changes continuously — that is why it is called stepless. Because it is still a transformer, it isolates the load and keeps a clean sine wave, which matters when you are testing equipment that is sensitive to the chopped waveforms some cheap regulators produce.
Our range at a glance
- Single-phase TDGC2 series — 500VA up to 30KVA, 0-250V or 0-300V output, the standard for labs and workshops.
- Digital display models — TDGC2J and TDGC3 with LCD readout showing output voltage and current, handy for test benches.
- Three-phase TSGC2 series — 3KVA to 6KVA and up, 0-430V output, for motor testing and three-phase equipment.
- Socket options — US style sockets as standard; EU, UK or AU available, or bare terminals for panel mounting.
Choosing the right rating
Size a variac the way you size any transformer: load plus headroom. For continuous duty, pick a rating at least 30% above your load. If the load has a motor or a transformer inside it, allow more — inrush will be several times the running current. One thing buyers often miss: the knob position matters. A variac rated 2KVA delivers that at full output voltage; at lower knob positions the output current limit stays about the same, so you do not gain much headroom by turning it down.
Three Phase
Three Phase Variac (TSGC2 Series)
A single-phase variac cannot drive three-phase equipment, and that is the request we get most often from industrial buyers. The TSGC2 series is our three-phase answer: three ganged brush assemblies on a common shaft, so one knob adjusts all three phases together and the output stays balanced. That balance is the whole point — if the phases drift apart, motors run hot and test readings stop meaning anything.
- TSGC2-3KVA — 3000VA, 0-430V output, the usual choice for three-phase motor testing and small control panels.
- TSGC2-6KVA — 6000VA, 0-430V output, for larger motors, workshops and production test benches.
- Larger ratings — we wind three-phase units up to 30KVA to order, including 380V and 415V line voltages common in the Middle East and Africa.
Typical three-phase variac jobs: running a three-phase motor at reduced speed during commissioning, testing three-phase power supplies and inverters, calibrating panel meters, and slowly energising rebuilt equipment so a fault shows up before full voltage does. If you are not sure whether your application needs single or three phase, tell us what you are testing and we will confirm.
Pricing
Variac Price & Ordering
Buyers searching for a variac price usually get one of two answers: a number that turns out to be for a model that will not do the job, or a request for your email before anyone will talk. Here is how our price actually works, with nothing hidden.
| What you are buying | Capacity (VA), single or three phase, analog or digital meter, socket standard, housing |
| Price driver 1 | Capacity — price scales with copper and core weight, so a 3KVA unit costs roughly three to four times a 500VA unit |
| Price driver 2 | Phase — three-phase units carry three windings and cost materially more than the same VA single phase |
| Price driver 3 | Digital LCD metering adds a small premium per unit over analog |
| Price driver 4 | Order quantity — container-load volumes move the unit price down, and OEM branding is available from MOQ |
| MOQ | 10 pieces per model |
| Lead time | 15–25 days production, plus shipping |
| Terms | FOB Ningbo or Shanghai; other Incoterms on request |
How to get a firm variac price: send us the capacity and voltage range you need, the quantity, and the socket standard your market uses. We reply with an FOB price and a delivery date within 24 hours — no obligation, and no requirement to register first. If you are comparing suppliers, ask all of them for the same three things: copper winding, load test before shipment, and the actual VA rating at full output voltage. Those three answers separate a variac that lasts ten years from one that fails in the first season.
Why buy from the factory
We have been winding variacs in Yueqing for years, and build quality is the difference between a tool that lasts a decade and one that carbon-fouls in a year. Every unit gets a no-load and load test before packing, the brush arm is aligned and torqued at the factory, and we stand behind it with a 12-month warranty. MOQ is 10 pieces, lead time 15 to 25 days, FOB Ningbo or Shanghai — and we can print your brand on the case if you are reselling.
Applications
Applications & Benefits
- Laboratories and universities for experiments and calibration
- Equipment repair benches and appliance testing
- Motor soft-start during test runs
- Lamp brightness and heater testing
- Plating and surface-treatment bath control
- Three-phase equipment commissioning and verification
FAQ
Questions Customers Ask Us
What is the warranty?
12 months from delivery on every unit.
What is the minimum order quantity?
From 10 pcs. OEM branding available from this volume.
Can you customize voltage and capacity?
Yes — any voltage combination, capacity and enclosure is built to order.
What is the typical lead time?
15–25 days production plus shipping to your country.
What is the price of a variac?
It depends on capacity, single or three phase, and metering. Send us your capacity and quantity and we return an FOB price within 24 hours.
Do you make three-phase variacs?
Yes. The TSGC2 series covers 3KVA to 6KVA and up with 0-430V output, and larger ratings are wound to order.
What is the difference between a variac and a voltage stabilizer?
A variac is manually adjustable — you set the voltage. A stabilizer holds a fixed voltage automatically. They solve different problems; we build both and will tell you which one your case needs.
Guides & Articles
Related Categories
Browse DT/ST Series Transformers · Step Up & Step Down Transformer · Control Transformer · Variable Transformer
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