Converting a 100v appliance to work on 110v

Discussion in 'The Projects Forum' started by someother, Jan 3, 2009.

  1. someother

    Thread Starter New Member

    Jan 3, 2009
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    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.
     
  2. leftyretro

    Active Member

    Nov 25, 2008
    394
    2

    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
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    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.
     
  4. someother

    Thread Starter New Member

    Jan 3, 2009
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    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.
     
  5. Audioguru

    New Member

    Dec 20, 2007
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    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.
     
  6. Clef

    New Member

    Jan 4, 2009
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    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 ).
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    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.

    Yes, and it would rapidly burn out.

    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.

    I don't know of a 1200W dimmer.
    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!
     
  8. leftyretro

    Active Member

    Nov 25, 2008
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  9. SgtWookie

    Expert

    Jul 17, 2007
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    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.
     
  10. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    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.
     
  11. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    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.
     
  12. someother

    Thread Starter New Member

    Jan 3, 2009
    3
    0
    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.
     
  13. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    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.
     
  14. Wendy

    Moderator

    Mar 24, 2008
    20,766
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    Japanese Inverter for the motor?
     
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