110V to 100V

I made the mistake of bringing a fuzzy logic rice cooker back with me from Japan and thought I could use a converter I already had at home but when I looked at the specs on the cooker, it says 100V, 1100W, 20A. My converter is rated for under 100W. So I found someone selling a 110V to 100V step down transformer at 1500VA and 15A max. Is 1500VA the same as 1500W? Will the 5A make any difference? I'm pretty clueless when it comes to this stuff but want to make sure I don't do anything that will damage the cooker since its electronics are quite complex as far as rice cookers go. The seller is not a dealer so he is not sure either. Any help would be appreciated. Thanks!

Reply to
atasaka
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On Fri, 5 Sep 2003 01:58:14 -1000, atasaka Gave us:

100V at 20A is 2kW. A single 120 volt line at 15 amps is only 1.8kW

I'd find out what the thing really uses. Also, are you sure that your mains are at 110V? A 110 to 100 step down xfmr is only a 120 to

109V conversion. The heating element in the cooker wouldn't mind so much, but the front end supply and control electronics for it may.

Anyway, their 1100W claim doesn't jibe with their claim of a 20 Amp draw. One or the other is not correct. Either the unit only draws 1.1 amps, or somebody doesn't know how to do the math in that japanese rice cooker factory. Maybe he was using fuzzy logic too! :]

Reply to
DarkMatter

"VA" is the acronym for "volt-amps" and is generally equivalent to "W" (watts). Calculated by multiplying the volts and amps.

I would just try the 1500VA transformer and monitor it to see if it overheats in use.

The numbers "100V, 1100W, 20A" don't really compute. I believe the 100V because that is the domestic standard in Japan. And the 1100W *sounds* reasonable. But 1100W at 100V is only 11A (1100W divided by 100V). Dunno where the "20A" comes from. Maybe it is an indication that they recommend using it on a dedicated 20A branch circuit.

Taking them at their word (at least the parts we choose to believe :-), it may draw only 11A in which case, the 15A transformer would be adequate.

Reply to
Richard Crowley

from

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converter

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go.

AFAIK the tolerance of the power supply voltage SHOULD mean that it will work OK off 110. If it were mine I would certainly try it, maybe through a variac slowly if ti were very expensive but i am pretty certain it would be OK.

That should get me a flaming :)

Reply to
Mjolinor

It shouldn't be an expensive transformer by the way. You could use a 110 to 10 volt transformer of 150 (or 200) VA.

The tricK: the primary is wired to your 110 volts. The secondary is put in series with your 110 volts, so that it subtracts (measure this...).

The transformer is asked to deliver 15 (or 20) amps at 10 volts. That's a 150 to 200 watt transformer.

Thomas

Reply to
Zak

After reading your post, I looked at the rice cooker again and next to the

20A in katakana characters, I think it reads "fuse" but I'm not too sure. Could this mean the rice cooker has a fuse built in that can handle up to 20A? Thanks for every>
Reply to
atasaka

Your rice cooker will pull 11 Amps at 100 V and if you run it on 120 V it will pull about 13 amps. The reason for the 20 Amps being indicated, is that in Japan, the standard panel breaker for home kitchen appliance use is 20 Amps. Here in North America the standard is 15 Amps. As for the transformer, you should be okay with the 1500 VA unit.

The cooker would probably work on 120 V, but it will be a bit hard on it. I would prefer to use the proper rated voltage. From 100 to 120 V there is a 20% difference. This is a lot for continuous use. Running the cooker on a higher voltage may definitely lower the life span of the unit.

I am curious to know the company that made your rice cooker. Before Sony got in to the TV and electronics business, they were a rice cooker and small appliance manufacture. Infact, they were one of the best made.

--

Greetings,

Reply to
Jerry G.

I thouhght the original post said he wanted to run it from 110 volts but I can't find it to check?

Reply to
Mjolinor

Domestic power in North America is variously referred to as:

110, 115, 117, 120 V. Likely varies even wider than that. Don't try to calibrate your voltmeter from the power line!

To quote "Mr. Mom"

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Ron Richardson [Martin Mull]: "Yeah? Are you gonna make it all 220?" Jack Butler [Michael Keaton]: "Yeah. 220... 221, whatever it takes."

Reply to
Richard Crowley

More likely that they recommend using it on a 20A circuit. You might be able to get away with a 15A circuit @ 110V, but I would consider the age/condition of the wiring if it were my house!

Reply to
Richard Crowley

I must have missed the bit where he said he was in North America as well.

Reply to
Mjolinor

Well.... Hawaii is "North America" by adoption! :-)

Reply to
Richard Crowley

brrr. Wrong answer.

100V at 20A is 2kVA and has to be multiplied with cos(phi) to get real power (in W or kW). For resistive loads cos(phi) = 1, so then -- and only the! -- the 2kVA = 2kW. If cos(phi) = 0 (pure inductive or capacitive loads) the 2kVA = 0W. Nothing, zilch, nada
Reply to
Steven

On Sat, 06 Sep 2003 18:25:43 GMT, "Steven" Gave us:

It is a purely resistive load, dipshit.

Reply to
DarkMatter

Given that rice cookers today are pretty inexpensive, and power converters are not, I tend to believe that this guy would be well advised to simply purchase a new rice cooker!

Harry C.

Reply to
Harry Conover

Maybe it uses a 100VAC 20 amp heating element with a TRIAC in series, which never allows the full continuous 20 amps thru. I.e. it's really a PWM controlled heater. And it might actually draw 20A peak for fractions of a second.

Reply to
Lizard Blizzard

Harry Conover wrote: [snip]

Another thought. Advertise that you have a rice cooker that you brought from Japan recently and you're looking to trade for a U.S. one for someone who is going to Japan. Equivalent make, model, capacity, etc..

Reply to
Lizard Blizzard

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