Crockpots VS Crackpots

[George Boley]

Hi Gang,
I have read with interest, the post on generating ideas for crockpot cooking. I share a couple of crackpot ideas of my own.

The first one is an old tried and true plan. Put what ever you want to cook on the exhaust manifold and let it simmer. This was done a great deal in the old days. I tried it myself once. The Model T Ford even offered a small oven that bolted right on the manifold. Another idea, with a little ingenuity you can fashion yourself a Windsor Kettle by soldering a copper coil to the bottom of a pot. Then pipe your 190 degree radiator water throught it. Guaranteed to cook in no time.

The second one is open to dispute. So, at the risk of being "stuck on stupid" again, I offer it. Something in the back of my mind tells me you don't have to invert your DC power To AC in order to run an AC resistance wire (heating) appliance. In other words I beleive you can cause a heating coil to heat up with straight DC voltage right off your alternator. It's just a matter of keeping the wattage of the heating coil within the output capacity of the alternator. Do "watts divided by amps = volts" when it's DC volts. I bet not! So how is it figured?

I'm sure this post is really going to light up the board. May we be blessed by feedback from the gurus of the club, similar to the likes of Bill Ruh, Bill Hemme, Mel Wilbur, Sab Sasaki and so many other respectables.
OK you guys, it's alright to pile on now!

George B

[whemme]

George,

You are correct that if the crockpot uses only a resistive wire element in it for heating that this element will heat just as well using a DC voltage instead of an AC voltage, assuming that a 120 VDC were available to apply to it. But this is a problem. The AC voltage is typically 120 whereas the DC voltage available to us in our Born Free is only approximately 12.5 VDC. The formula for calculating wattage of interest here is WATTS = (VxV)/R where V is the voltage and R is the resistance of the heating element. By the way, wattage by definition is equal to heat. Double the wattage and you double the heat.

Lets say that you have a 250 watt crockpot designed to run off of 120 VAC. The resistance of the heating element would be 57.6 ohms calculated using the above formula in reverse. If you were to rewire this same crockpot so that you could connect it to a DC supply of 12.5 VDC, the resulting wattage would be severely reduced, again using the above formula, to only 2.71 watts. This would result in a 98.9% reduction in wattage (heat). This would not work!

You would need to somehow transform the 12.5 VDC up to 120 VDC via a DC to DC converter and that kind of device, unfortunately, would be more expensive than our typical inverter. So to do this, you might just as well use a commonly available inverter.

[George Boley]

Bill,
Thanks for your detailed response. I knew I would end up learning alot from my post, I plan to copy it, absorb it and then file it. Look forward to meeting you in Iowa. George B

[Mel Wilbur]

George,

I got lost around the third sentence of Bill's technical reply so I told the cook to just keep on using the old fashioned way to prepare our meals, you know, the microwave/convection and gas stove way.

[Barbara & Ken]

George,

I got lost around the third sentence of Bill's technical reply so I told the cook to just keep on using the old fashioned way to prepare our meals, you know, the microwave/convection and gas stove way.

And I'll do the same. If I want to use a Crockpot, I'll wait till we have shore power, run the generator, or get an inverter. Too many "wiggly amps" in the earlier explanations for this blond to understand.

Barbara