Converting a 100v appliance to work on 110v

Thread Starter

someother

Joined Jan 3, 2009
3
I just purchased an electric hotplate grill from Japan that is rated at 100v 1200watts. For portability and ease of use, I would prefer to convert the device to run on 110v instead of using an external stepdown transformer. What is involved in this conversion? Is it as simple as replacing the hotplate's transformer with a 110v 1200w transformer, or is there more to it than that? Thanks in advance.
 

leftyretro

Joined Nov 25, 2008
394
I just purchased an electric hotplate grill from Japan that is rated at 100v 1200watts. For portability and ease of use, I would prefer to convert the device to run on 110v instead of using an external stepdown transformer. What is involved in this conversion? Is it as simple as replacing the hotplate's transformer with a 110v 1200w transformer, or is there more to it than that? Thanks in advance.

Most heating type devices don't use internal transformers but rather just wire the heating element to the AC voltage input. A 1200 watt transformer would weigh probably over 15 pounds all by itself!

The heating elements are sized such that they have the proper resistance for the specified voltage input. That being said, I think your heating hotplate will work fine on 110vac Vs 100vac, especially if uses a adjustable temperature control which turns on and power the power once the hotplate has reached the desired temperature.

Lefty
 

SgtWookie

Joined Jul 17, 2007
22,201
Actually, in the US it's 120v 60Hz. I think Japan has 100v 50Hz.

You'll be running the hotplate at 20% over it's rated voltage.

As Leftyretro mentioned, a transformer would be prohibitively expensive.

Use it until it burns out (which won't be long) and then purchase a unit that has the correct voltage rating.
 

Thread Starter

someother

Joined Jan 3, 2009
3
Thank you both for the responses. It is a single-purpose appliance meant for cooking pancake balls, I would love to buy one in the states but no such device exists here so I'm stuck modifying this one. Unfortunately there is no temperature adjustment on the hotplate, and since it would be drawing 20% more than it should, I would think that would make it too hot to cook with. What if rather than putting a transformer on the front end, I put a resistor before the heating fillament? Would this allow me to compensate for the added 20%? What about plugging it into a dimmer switch rated for 1200 watts (if one even exists)? Even if either one of those options brought down the temperature, would the life of the unit still be dramatically shortened? It may be worth paying the $80 for a 1500 watt stepdown transformer. I should also mention that I'm pretty sure it runs on both 50 and 60 hz as half of Japan runs on 50 and the other half on 60, many Japanese appliances run on both.
 

Audioguru

Joined Dec 20, 2007
11,251
Incandescent light bulbs are also a heaters. So look for a big dimmer that is used in a restaurant.

A heater is not affected by 50Hz or 60Hz.
 

Clef

Joined Jan 4, 2009
1
You can use simple thyristor power operation device to prolong life of your grill . It easy to operate power and it is small in comparision with transformer . You can see it in the shop ? It is used to regulate lamps brightnes (incandescent lamp ).
 

SgtWookie

Joined Jul 17, 2007
22,201
Thank you both for the responses. It is a single-purpose appliance meant for cooking pancake balls, I would love to buy one in the states but no such device exists here so I'm stuck modifying this one.
The Japanese didn't invent Aebelskivers, the Danish did. What a delicacy.
Try this Google search:
http://www.google.com/search?hl=en&q=aebleskivers&aq=7s&oq=abels
I haven't had any Aebelskivers for quite a while :(, but they are a most delicious item.

Unfortunately there is no temperature adjustment on the hotplate, and since it would be drawing 20% more than it should, I would think that would make it too hot to cook with.
Yes, and it would rapidly burn out.

What if rather than putting a transformer on the front end, I put a resistor before the heating fillament? Would this allow me to compensate for the added 20%?
OK. 100V @ 1200 Watts means a current of 8.33 Amperes. Ohm's Law helps here:
I=P/E, or Current = Power in Watts / Voltage

What you now need is a resistor measuring 1.67 Ohms that is capable of dissipating 240W of power safely. These are very expensive resistors if you buy them new.

Skycraft Surplus in Orlando happens to carry a variety of high-power resistors. Their website is here:
http://www.skycraftsurplus.com/
You could give them a call and see if they have a 1.6 to 1.7 Ohm resistor in their collection capable of 250W; I'm virtually certain they do.

Another option would be to make an extension cord out of AWG 20 stranded wire, you would need 160 feet total (80 feet for hot, 80 feet for neutral) and another 80 feet for the ground wire (if your hotplate is so equipped). You cannot have the extension cord coiled when in use with your hotplate, or it will overheat and burn up.

What about plugging it into a dimmer switch rated for 1200 watts (if one even exists)?
I don't know of a 1200W dimmer.
Even if either one of those options brought down the temperature, would the life of the unit still be dramatically shortened? It may be worth paying the $80 for a 1500 watt stepdown transformer. I should also mention that I'm pretty sure it runs on both 50 and 60 hz as half of Japan runs on 50 and the other half on 60, many Japanese appliances run on both.
The frequency isn't an issue with hotplates; it's the applied power.

Check out the Aebelskiver links - but don't eat too many of them; they're fattening!
 

SgtWookie

Joined Jul 17, 2007
22,201
Well if you are determined to solve it, here is something that would work and might be useful as a general purpose piece of equipment to have available for other things. Plus it would like as sort of a temperature control for your hot plate.

http://www.allelectronics.com/make-a-store/item/SC-10M/10-AMP-VARIABLE-TRANSFORMER/-/1.html
I was thinking of a less expensive solution, but a Variac would certainly work.

The one you posted is only rated for 10A; our OP's hotplate requires 12A.

Here's a less expensive (2/3 price) Variac with sufficient current rating (50% more) from one of my favorite vendors:
http://www.mpja.com/prodinfo.asp?number=15163+TR
It's still over $105 though - quite a bit to make Aebelskivers.
 

mik3

Joined Feb 4, 2008
4,846
If the current drawn by the device is constant you can use an inductor with the appropriate value to drop the excess voltage across it. The inductor is better and more efficient than a resistor because it has a low resistance and it dissipates little power.
 

eblc1388

Joined Nov 28, 2008
1,543
Perhaps one can replace the internal TRIAC of an existing lamp dimmer by isolated case/isoTab high current TRIAC of 15A or more to get the required wattage.
 

Thread Starter

someother

Joined Jan 3, 2009
3
Thank you all so much for your help.

It's true, the Japanese didn't invent aebleskiver, but they did invent an electric pan that automatically rotates the balls. Here's a youtube link of this little gem in action:

http://www.youtube.com/watch?v=VSDg72oVMdQ&feature=related

In Japan, they call them takoyaki, and they are savory rather than sweet, and usually include a piece of octopus in the middle. I can't wait to try both versions.

Having checked a few more websites with google translator, I've found out some more info on this device. It does, in fact, have a temperature control, so perhaps dialing it down could be the answer? However, it seems the device has 2 plugs, one for the motor (100v 5 watts) and one for the heating element (100v 1200 watts). The device also has an outlet on it, and from what I can tell, you plug the motor into the wall, and the heater into that outlet. I have found a stepdown transformer big enough to handle the entire thing, but as leftyretro said, it's one heavy box, and at $85 plus shipping, it doubles the cost of the device. I did find a small stepdown transformer rated at 50 watts for $15 though, so what if I were to plug the motor into that to protect it and perhaps keep the speed correct, and then plug the heating element directly into the wall and use the thermostat to turn the heat way down? Does that sound like a good idea, or should I still try a resistor, an inductor, or an extension cord on the heating element to protect it too? Again, thank you all so much for taking the time to help me.
 

mik3

Joined Feb 4, 2008
4,846
Use the transformer for the motor and plug the heater directly into the socket. It will heat quicker but it will stop because it is controlled by the thermostat.
 
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