I'm entertaining an idea of making a small power supply to get a certain hot air brush (For hair styling) to function on the Japanese power grid.

I like this hot air brush that runs only on 120V/60Hz and would like to use it on a study abroad trip coming up in June to Mishima, Japan (Which has a 100V/50Hz mains voltage/frequency in the place I'll be staying.)

What would be a reasonable solution to running a 1100W hot air brush like this that on the 100V/50Hz?

I had an idea of using either a full bridge rectifier (With capacitors (Although I haven't run the formulas for sizing)) or an 18650 battery bank -> 1500W inverter.

Are there other practical solutions that I missed?

EDIT 0: The hot air brush is a Revlon One-Step Volumizer (https://www.amazon.com/Revlon-One-Step-Hair-Dryer-Volumizer/dp/B01LSUQSB0/ref=sr_1_1?keywords=revlon+ht+air+brush&qid=1553485451&s=gateway&sr=8-1-spell)

  • \$\begingroup\$ Some areas in Japan have separate Earth grounding. Some don't and just float the entire mains supply. That may be a small issue for you that you haven't mentioned above. But in general, it's likely your device will "just work," though it may not do so with the same heating or rate of air flow. The heater is easy -- it will operate on a lower voltage than expected and will heat up less. (Just nichrome, or similar.) The fan is the main thing. But it will probably also work, if somewhat slower. All in all? A maybe. \$\endgroup\$ – jonk Mar 25 at 3:29
  • \$\begingroup\$ Can you tell us the model? It is possible that the same unit is available in Japan. It is also possible that it will work with the difference in voltage specs, but make the fan run 1/6 slower. \$\endgroup\$ – George White Mar 25 at 3:31
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    \$\begingroup\$ It's quite likely that it'll work fine without any adjustment. If it doesn't heat up enough, a transformer to increase the voltage will probably be all you need; frequency conversion is expensive and probably unnecessary. \$\endgroup\$ – Hearth Mar 25 at 3:33
  • \$\begingroup\$ The heat is proportional to V squared over R. From 120 V to 100 V will be a 30% drop. And, as I mentioned, the fan will go 16% slower. \$\endgroup\$ – George White Mar 25 at 3:40
  • \$\begingroup\$ @Hearth You're Probably right. The seller says not to use it on 50Hz, but I'm not so sure they know what they're talking about. They're probably not knowledgeable on the electrical specs aside for "Doesn't work outside the US" \$\endgroup\$ – Sarah Szabo Mar 25 at 3:46

I think it will work as-is. It will provide about 30% less heating and similarly less air volume due to the slightly lower voltage, and frequency won't matter to the low voltage DC motor typically used (usually it's in series with the element with a bridge rectifier to provide the DC to the motor).

You could buy a standard 110:24V transformer, mount it in a box, and step up the voltage to get to full horsepower, but that's a lot of trouble, and might contravene some Japanese regulation or another if it's not done correctly and safely. It's 1100W so about 9-10A so you'd need a relatively expensive and heavy 240VA 120:24 50/60Hz transformer, and you'd need to wire it so that it adds to the mains voltage. It might cost more than just buying an ionizing hair dryer in Japan, which would probably be pretty nice.

OP probably knows this, but Japan is part 50Hz and part 60Hz, pretty much everything West of where they are going is 60Hz, but their town (and Tokyo) are 50Hz.


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