Monday, February 23, 2009

How to Make Popcorn with Your Computer



I still want a toaster oven in my computer's tower for late night snacking.

9 comments:

hale-bopp said...

Cute, but I am calling BS (although you probably suspect as much and may even be posting this just to razz me :)

A USB 2.0 port has a max current of 500mA (.5A) at 5V. Power = IV so the max power of a USB port is a measly 2.5 Watts!

OrbsCorbs said...

Well, my old CRT monitor literally burst into flames a few months ago (mostly smoke, but there was some fire), so I suppose I could've made Jiffy Pop on that.

Lizardmom said...

too funny, looks like a get-together experiment for fun :)

Hale, how's April looking??

kkdither said...

I put my kernels in a brown paper lunch bag and microwave 2 minutes. Air popped Styrofoam. You can always add some melted butter if you care to fatten it up. Way better than the pre-bagged microwave stuff with the glowing yellow whatever-it-is on it.

MinnesotaChick said...

I prefer popcorn the old fashioned way.. made on the stove in a big kettle. :)

Huck Finn said...

I disagree with Hale-Bopp. My reasoning:

The lights being used are 2.8 volt .3 amp. USB ports put out a regulated 5 volts. If the lights are run in series, total volts they "could" suck would be 5.6 volts (2.8 x 2). The amps however would stay at .3 amps. This is due to the wiring in series which if you look real close at the hook up connections, is evident.

.3 amp is under the .5 amp Hale-Bopp has pointed out to us, so it is possible...

hale-bopp said...

Huck, the USB port could power the lights...they even make portable reading lights that connect to USB ports. The problem is with using it to pop popcorn.

Here are the numbers...assume a 10g kernel of popcorn that is 10% water (that's a little low, but makes the math easy). So 1gram of water per kernel needs to be heated from 20C (room temp) to 100C and then boil to pop the kernel. The heat capacity of water is 4.18J/gC so that takes 334J+2260J (2260J/g is the heat of fusion of water) for a grand total of 2594J. A power of 2.5W takes over 1000 seconds to deliver that much energy...and that assumes 100% of the energy goes into the kernel (which we also know is false) and it would take over 17 minutes to pop ONE kernel...and every approximation I made underestimated the time (that is so long, I bet we would have to start taking cooling rates into effect as the kernel got warmer which would make it longer still.)

So while you could light the lights, you definitely could not use them to pop popcorn using a USB power supply! How's that for late night geeky caclulations!

kkdither said...

You geeky guys are making my head hurt! DA and I could just build a fire for you and get some jiffy pop? :)

Huck Finn said...

Hale-Bopp I know your math explains it well, but you must be overlooking something. I see popcorn popping. It could be there is a different power source or heating element in the shot, but there is popcorn popping when he puts the glass jar on as a lid.

Now I'm going to have to go find the stuff to do this and debunk it.