Homemade 100W resistor?

Christmas light bulbs in parallel.

Cheers,

Phil Hobbs

Resistance wire ?

Old fashioned electric fire elements ?

Graham

A light dimmer?

Hi, Claus -

I bought a toaster at a garage sale for $.50 and it made a dandy 16R, 900W resistor for DC loads. I later dismantled it and made several resistors from it. Two of them were 12R at 300W.

Cheers, John

Take a smaller resistor, say 5 or 10 watts and operate it in a coffee can full of water. It works great and will easily dissipate 100 watts in water. Your voltage is about 45 volts max which should be ok in water. For higher voltages, use oil instead of water. Bob

always needing

the best way to make a 100W resistor out of found

in homemade construction? Something with a

would be handy.

accept a

advice on this topic.

Christmas light bulbs in parallel.

Cheers,

Phil Hobbs

On Tue, 21 Mar 2006 08:29:07 +1030, Claus Jensen Gave us:

Your best bet is to visit a military surplus electronics store, OR try a search on E-Bay for "power resistors". I saw several hundred hits.

Then, you can string together an array of smaller values, and use taps to attach and set up nearly any value you want to use. Once your circuit has been characterized, and you know the value you need for your design, you can refer back to ebay for a match or pair (or the like) that will get you the desired target value and wattage. Remember to use a power level resistor that is at least 1.5 times the actual wattage you really wish to use it for if you want any longevity and value stability at all.

On 20 Mar 2006 17:51:48 -0800, "linnix" Gave us:

Do you mean "rheostat" If so, yes, that would be a good thing to hunt up on E-Bay as well.

Hello Claus,

Garage hacking is right up my alley. We take resistors for granite yet they are difficult to make because of the limited materials we have for home brew that has resistance.

Here is my approach:

One method might be use the carbon electrode inside a 1.5 volt cell with small hose clamps to fasten your wire on each end. I don't know the resistance of the rod, it may be to low.

Or

Get a rubber Tupperware type kitchen container about 6" diameter and

Fill with water, add a pinch of salt.

Make two electrodes out of piano wire, stab them through about 4" apart. Adjusting the salt and the depth of the electrodes will allow you to dial in 1-20 ohms.

It does work at lower currents, 1 to 20 ohms I just tried it!

The down side, electrolysis will probably eat up the electrodes. The over all approach may be to unstable for your purpose or you might get a boil over at 2 amps.

Good Luck,

• * * Christopher

Temecula CA.USA

If you can get hold of brass or phosphor bronze strip (shimstock or draught-excluder?), cut a strip about 0.5" wide and a couple of inches long. Wrap it as a single turn around an electric fire bar element (like a 'P' clip); then take it off and drill holes in the two projecting ends so that you can nut and screw it loosely back into place.

By sliding it up and down, you can tap the element to any required value; then pinch it tight with the screw.

Mount it in a place where it isn't going to set anything on fire.

I'll give you some resistors in exchange for granite......

When someone changes their car headlamp bulb because the normal filament is open circuit, usually the high beam filament is fine. This can be used as a free power resistor, however the value will change depending on how hot the filament is. Sometimes that is even a useful property, e.g. as a current limiter.

Chris

For what sorts of current and voltage?

-- Paul Hovnanian mailto: snipped-for-privacy@Hovnanian.com

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