Rheostat for Rotisserie

Discussion in 'General Electronics Chat' started by Gcan61, Nov 24, 2014.

  1. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...I own a Ronco Showtime Rotisserie, and I would like to control the temperature of the rotisserie. I figured I would just cut a rheostat into the heating circuit and turn it up or down depending on my needs. I just don't know what type of rheostat to buy. It's a 1250 watt oven. Can anyone give me any suggestions on how to accomplish this. Thanks in advance.

    Geoff
     
  2. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    Just obtain a rheostat rated higher than 1250W. But rheostats are rarely used in this case anymore, as they don't provide good control. You may want to consider a 2000W dimmer. But even better is a thermostat rated to handle your heating element.
     
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I like the dimmer idea. An electric heating element is no different that an incandescent light bulb (or set of 20 x 60 watt lights). Make sure to look at the wattage when you buy - it could get pricy.
     
  4. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...is a rheostat and dimmer the same thing??? Can you post a webpage where I would find a thermostat that would handle my heating element. I've used a PID with a temperature probe in the past involving a relay to control temperature...would this be the same thing??
     
  5. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    No, a rheostat and dimmer are different. A rheostat is a potentiometer on "steroids". To be honest, I misread the results of my google search, reading 1500Ω as 1500W. Now I don't find a rheostat over 1000W.
     
  6. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...the heating element in my ronco rotisserie...it's the same as you would find in an oven...could I just use a oven heater switch????
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Harbor Freight sells a "light dimmer" type of foot control for $12.99, which means about $10.39 with a 20% off coupon:
    http://www.harborfreight.com/power-maintained-foot-switch-96618.html

    You could control it with your foot and get the satisfaction of be integral to the process, or salvage what you need from it to make a constant speed. It is rated at 1800W (15A at 120V), but HF's ratings are sometimes a little optimistic.

    John
     
  8. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...jpanhalt thx for the reply, but that's a little to radical for me, besides rotisseries cook for hours on end. This heating circuit is really simple...one wire to the top of the heating element ...one wire return. You turn on the rotisserie and the element heats up. There's got to be a simpler way.
     
  9. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Don't they usually have a 2 or 3 position heat control on them?
    The heavier duty controllers such as for routers and power tools may be able to handle it, they usually put a heavier duty triac in them, an oven controller could probably do it but expensive.
    You have to make sure you insert it into the element lead only and by-pass the motor control.
    Max.
     
  10. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...No Max...you turn on the Ronco Rotisserie, and the element just heats up to full power. The three position switch is for: rotation with heat on, no rotation with heat on, and rotation with heat off. From the circuit board there are two wire that go to the heating element...I just thought if I could put in some type of voltage control on one of the lines I could adjust the amount of voltage going to the heating element thus control the amount of heat given off. I have very little schooling in electronics...hence is why I asking the professionals...:)
     
  11. MaxHeadRoom

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  12. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...here is one persons answer to controlling the temperature, but using a diode it's only cut in half
     
  13. MaxHeadRoom

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    Jul 18, 2013
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    That is only OK if you just want 2 settings and not infinite control.
    Max.
     
  14. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...I like that speed control idea...fairly affordable...but would the 1250 watts be a problem???
     
  15. shortbus

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    Sep 30, 2009
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    According to Roncos website, these have 'a perfect preset temperature'. So they must have some form of a temp regulator. You might be able to hack the control board to change that. Probably has a thermal sensor to set the on-off of the heaters to keep the unit from over heating. Hacking into that may allow it to be varied.
     
  16. MaxHeadRoom

    Expert

    Jul 18, 2013
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    No under 15amps, and I assume you are running it off of a 15a socket anyway?
    Max.
     
  17. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...yes it's preset ...but if I wanted to slow things down a bit I would need to control the temp
     
  18. shortbus

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    Sep 30, 2009
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    Thats what hacking the thermal sensor will do. You could even pull a control circuit form a toaster oven to control the heat in the Ronco. A toaster oven doesn't cost very much at a second hand store or Goodwill.

    The one thing no one is saying about the speed control idea is what it will do the the motor that turns the spit. It is probably a shaded pole motor and won't react well to the speed control. And even if it does, slowing the motor and lowering the heat at the same time, won't that still make cooking temp of meat similar?
     
  19. Gcan61

    Thread Starter New Member

    Nov 24, 2014
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    ...there is no thermal sensor...this rotisserie is a very simple setup...I'm trying to control the voltage between the circuit board and the heating element...as in the YouTube video ...the motor is on a separate circuit.
     
  20. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I Covered that in post #9. ;)
    Max.
     
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