Step Down Transformer for Electric Blanket and Heated Products
An electric blanket is a simple resistive heater that runs for hours while you sleep — and that combination makes the transformer choice more important than it looks. A US 110V blanket in a 220V country needs a step down transformer that runs cool through the night with real protection. This guide covers sizing, the safety requirements, and why a cheap converter is the wrong answer for a device that touches your bed.
Why electric blankets are a special case
An electric blanket draws 50-200W — small numbers — but it runs for 8 hours straight, in a bedroom, next to fabric and sleepers. The transformer is energised all night, which makes continuous-duty rating essential. And because it is a heater in a flammable environment, RCD protection is not optional. A blanket that shorts while everyone sleeps is the exact scenario protection is built for.
The good news: blankets are resistive loads, so the sizing math is simple. The watts on the label are the watts the transformer must supply. What matters is not the size of the transformer — it is the quality of it.
Step down transformer size for electric blanket
| Blanket / product | Wattage | Duty | Recommended transformer |
|---|---|---|---|
| Single electric blanket | 50-90W | 8 hours overnight | 500VA |
| Double electric blanket | 90-150W | 8 hours overnight | 500VA |
| Heated throw / pad | 40-100W | 8 hours overnight | 500VA |
| Heated mattress pad | 70-150W | 8 hours overnight | 500VA |
| Blanket + bedside lamps | combined | overnight | 500-1000VA |
The ST-500 covers any single electric blanket with huge margin — a 150W double blanket at 30% load is barely warm. Even a blanket plus a phone charger and a bedside lamp fits on the 500VA unit. The transformer size is never the question with blankets; the protection and the duty rating are.
RCD protection is the real requirement
Here is the thing: an electric blanket is a heating element woven into fabric, in a bed, running for hours. The failure mode to fear is a short or a crack in the element that leaks current into the fabric. RCD protection on the transformer trips on that leakage in milliseconds, before the heat builds. The ST series includes RCD as standard, and for a blanket this is the difference between a safe night and a dangerous one.
Continuous overnight duty
Blankets run through the night at low power, cycling the element to hold temperature. The transformer is energised the whole time. Copper winding and margin keep it cool, silent and safe through thousands of hours of overnight use. An aluminium-wound unit running warm every night will not last the season.
Common mistakes with blanket transformers
- Using a travel converter. Blankets run 8 hours; converters are for chargers, not heaters.
- Skipping RCD. A heater in fabric without protection is a risk no one should take.
- Ignoring the duty rating. Overnight use is continuous duty; buy for it.
- Wrong primary winding. Output drift makes the blanket run hot or cold.
- Buying aluminium winding. Nightly use needs copper to stay cool.
Why buy from a factory directly
Wilmall supplies step down transformers for heated products — blankets, pads, throws — to distributors across Asia, the Middle East and Africa. Copper winding, RCD protection, continuous-duty rating and batch test records with every shipment. MOQ 1 pc for stock units, 10 pcs per model for custom voltage, 15-25 day lead time, FOB Ningbo or Shanghai.
Heated products beyond blankets
The same transformer class covers heated throws, mattress pads, foot warmers, and pet heating pads — all resistive heaters that run for hours. The sizing rule is identical: 500VA covers anything under 200W with huge margin. Distributors who stock the 500VA size for blankets can sell it across the whole heated-products range.
The protection requirement is identical too. Any heating element in fabric deserves RCD protection and continuous-duty rating. One SKU answers the whole category.
Voltage accuracy and heat control
Blankets control temperature with a thermostat that cycles the element. If the transformer output runs high because your grid is 240V and the unit was wound for 220V, the element runs hotter and the thermostat cycles differently — the blanket feels uneven, and the controls respond oddly. Order the transformer wound for your grid, or with input taps, and the blanket behaves as designed.
For a product that touches your bed, accurate voltage is a comfort feature, not a technicality.
Buying for resale: the heated-products range
Distributors stocking transformers for heated products tell us the 500VA size covers the entire blanket and pad market with one SKU. Private labelling from MOQ 1 pc for stock units, 10 pcs for custom voltage, and we can print the compatible product list on the carton so shop staff answer instantly.
Heated products are seasonal in some markets and year-round in others — cold climates and high-altitude regions sell them for half the year. The transformer demand follows the season, which suits distributors planning stock.
Warranty and support
Every Wilmall transformer carries a 12-month warranty, and we keep common spares for fast resolution. A blanket transformer that fails mid-winter is a bad week for the buyer. Batch test records ship with every order, and we respond to support enquiries within 24 hours.
Voltage accuracy in high-altitude markets
Heated products sell strongly at altitude, where nights are cold. High-altitude grids sometimes run slightly high or low, and the output follows the primary. For accurate heating, order the transformer with input taps so the output matches the blanket rating exactly. This is a free option and it makes the thermostat behave correctly.
A multimeter reading of the wall voltage settles which tap to use. It takes one minute and removes the guesswork.
Why the cheap converter is dangerous here
Travel converters are the wrong answer for blankets, and the reason is simple: they are rated for small intermittent loads like chargers, and they run hot at even 50% of their rating. A blanket runs at full power for 8 hours. The converter overheats, the insulation softens, and a hot converter next to fabric is exactly the risk nobody should take. A proper continuous-duty transformer runs cool all night.
This is the one appliance class where we actively warn buyers away from converters. The price difference is small; the safety difference is enormous.
Ordering, shipping and lead time
Send us your product list, your country voltage and the quantity. We confirm the transformer size, the winding and the socket in writing, then produce in 15-25 days and ship FOB Ningbo or Shanghai with full documentation. MOQ 1 pc for stock units, 10 pcs per model for custom voltage, private labelling available.
What an electric blanket actually draws, and why that misleads buyers
An electric blanket is a low-power device and that is exactly why people underestimate it. A double blanket is typically 100 to 150 watts and a single is closer to 60. On a 500VA transformer it looks like an easy load. The catch is that it runs for eight hours, so the load is present for the whole of that time rather than for the two minutes a kettle takes.
The second thing worth knowing is that the blanket controller is electronic. It uses a small triac or relay to switch the element, and that switching puts a train of small surges onto the transformer every time the thermostat calls for heat. A transformer with plenty of copper shrugs those off. A cheap converter with a minimum of copper passes them straight into the controller, and that is the controller customers complain has failed after one winter.
The two-hour test to run before the cold season starts
Before winter, run the blanket for two hours through the transformer and put your hand on the transformer case and on the plug. Both should be no more than comfortably warm. Then run your palm slowly along the whole length of the blanket. Even warmth across the surface is what you want. A single warm patch rather than a general warmth means a damaged element, and a blanket in that condition should not be used at all.
Do this with the bed empty and the blanket laid flat rather than folded. A folded blanket traps its own heat, so the element runs hotter than it would in use, which tells you nothing useful and can shorten the element’s life. Two hours in October is cheaper than discovering the fault in July.
Why the lead matters more on a blanket than on anything else in the house
An electric blanket is used at night, in a bedroom, usually with the lead running under the bed. That is a poor place for a thin lead and a worse place for a warm plug, because nobody looks at it. Use the shortest heavy lead that will reach, keep it clear of the bed frame where it can chafe against a sharp edge, and never run it under a rug or a carpet where you cannot feel whether it is getting hot.
The application guides cover the same reasoning for the other long-running household loads, which behave very differently from short-burst appliances even when the wattage looks similar.
The short version
A 500VA copper-wound transformer with RCD and continuous-duty rating covers every electric blanket, pad and throw on the market. The transformer size is never the question; the protection and the duty rating are. That is the whole heated-products story, and it is the answer we give every blanket buyer.
Frequently asked questions
What size transformer do I need for an electric blanket?
A 500VA transformer covers any electric blanket — single, double or heated pad — with huge margin. Blankets draw only 50-150W.
Why does an electric blanket transformer need RCD?
A blanket is a heating element in fabric, running for hours. RCD trips on leakage in milliseconds if the element cracks or shorts, protecting the sleeper.
Can a transformer run an electric blanket all night?
Yes, if it is rated for continuous duty with margin. Copper winding keeps it cool through thousands of overnight hours.
Why can I not use a travel converter for a blanket?
Travel converters are rated for small intermittent loads. A blanket runs 8 hours straight, which overheats a converter. Use a continuous-duty transformer.
Can I order blanket transformers with my brand?
Yes, private labelling from MOQ 1 pc for stock units, 10 pcs per model for custom voltage, with RCD and continuous-duty rating as standard.
Related reading
- Step Down Transformer 220V to 110V: Sizing and Safety
- Transformer Protection Devices Explained
- Step Up and Down Transformer Products
Get a factory-direct quote
Email info@wilmall.com or WhatsApp +86 197 3022 6757 with your product list and country. We confirm the size within 24 hours. MOQ 1 pc for stock units, 10 pcs for custom voltage.
