two power resistors as element

JohanWagener · 2003-07-06T17:07:47+00:00

Please comment on my calculationsIf I take two 10W resistors of 1k each and put them in parallel I would geta 500ohm resistor right? Now if I apply 220V over it there would be about0.44A flowing through it. That is power of about 98.6W. How long will ittake to boil 500ml of water?

Jul 06, 2003 22 Replies

Rate this thread:

nospam 23 years ago

Well yeah I know I was pushing it, some here seem to think the resistors will vaporise as soon as you switch on.

I already ran the same resistor at 10 x rated in water and predicted it would eventually fail from lead corrosion.

For 26 x rated I figured there would be too much localised boiling so went for oil which likely offers significantly less cooling.

The resistor is wire wound on something then coated with a thin layer of cement or ceramic loaded paint or something.

I would like to have tried one of the green glazed ceramic types, but didn't have a suitable value and power supply kicking around.

Vote

Roger Hamlett 23 years ago

don't

your

Yes. You will see, that with the right resistors, I am one of the people who believe it is probably possible, though like you, also expect corrosion of some form to be the most likely failure if the overload is 'reasonable'.

Fair enough.

You should try a much bigger one (evil grin - pictures of a person boiling a

300 gallon oil tank, with a couple of hundred watt 1 ohm resistors in series, connected directly to the mains...). :-)

Best Wishes

Vote