Do 40 Watt 1 Ohm resistors exist

[houlahound]

My local hobby store says no.

I want to draw a full 40 Amps from my power supply to play with a few formulas that give the magnetic field strength as a function of distance and current from a wire. The wire will be car battery cables. I have a calibrated Gauss meter for field measurements.

Would this set up work, what catalogues have a 40 Watt 1 Ohm resistor?

 

[Nidum]

Have you worked out how much power that resistor is really going to be dissipating ?

If nothing else the set up is potentially dangerous with real possibility of getting burns and arc flashes .

The resistors are readily available though :
[/PLAIN]
Near enough
[/PLAIN]
Dead on but not quite as good

 

[256bits]

My local hobby store says no.

I want to draw a full 40 Amps from my power supply to play with a few formulas that give the magnetic field strength as a function of distance and current from a wire. The wire will be car battery cables. I have a calibrated Gauss meter for field measurements.

Would this set up work, what catalogues have a 40 Watt 1 Ohm resistor?

Your volts, amps, watts do not make sense.
I could be missing something ...
40 watts through a 1 Ohm resister - that 6.3 volts and 6.3 amps.
40 amps through a 1 Ohm resistor - requires an emf of 40 v, thus your resistor needs to be 1600 watts.Try hooking up your power supply to lamps or headlights in series/parallel. ( 12 volt headlight draw about 40 to 60 watts, or are about 5 Ohms.)

 

[Nidum]

You'd need one of these

 

[houlahound]

Holy crap that's the resistor from hell.
Thanks all links.
Didn't think the numbers through before i posted.
My power supply, switched mode, is rated at 40 Amps. It is a variable voltage to 12 volts. I use it for my radio but never measured what current it draws. My license has limited watts for transmission. Don't know what antenna power equates to 40 Amps from the power supply.

 

[Windadct]

That is a 2000W answer to a 40W question - in short yes, they exist... there are a few ways to do this. But car headlamps are a good - low cost solution. Ray Bans anyone?

 

[jim hardy]

another 12v bulb

http://www.homedepot.com/p/Philips-...12-Volt-RV-Marine-Light-Bulb-415265/202743046

http://www.homedepot.com/catalog/productImages/400/ef/ef1b6739-90b2-48ab-9195-53c78d1ee29e_400.jpg

 

[houlahound]

I got some carbon rods about half inch diameter from an old time movie projector, will put them in sliding contact to make a variable resistance...what could go wrong?

 

[jim hardy]

what could go wrong?

read up on carbon arc light

http://www.edisontechcenter.org/ArcLamps.html

 

[houlahound]

Cool link, I wanted to build a lighting museum at one point, still might.

I am prolly the only living guy that lived in a time and place that carbide lights were the only source of lighting.

The good thing was we could take them to fishing holes and blow them up and get a feed of fresh fish, try doing that with yr fancy schmancy LED's.

 

[meBigGuy]

LOL --- you going to read, or you going to fish?

 

[jim hardy]

I am prolly the only living guy that lived in a time and place that carbide lights were the only source of lighting.

i thought i was the only one here that old.

Used to do spelunking in Missouri.

 

[houlahound]

Ha, ever use a party line ie a piece of fencing wire strung between trees for miles. A dynamo powered phone with a lead attached to the line by swinging a rock tied to one end to wrap around the party line. Lightning would blow your ears out or worse.

Everyone could listen to your conversations, and everyone could talk at the same time. Might have been why multiplexing and frequency division on a single optical fibre was born.

I still have a dynamo, use it to show kids induction, gives a hell of a boot.

If anyone would have tried to say one day we will have an internet they would have been burned at the stake for witchcraft.

 

[Jeff Rosenbury]

Holy crap that's the resistor from hell.
Thanks all links.
Didn't think the numbers through before i posted.
My power supply, switched mode, is rated at 40 Amps. It is a variable voltage to 12 volts. I use it for my radio but never measured what current it draws. My license has limited watts for transmission. Don't know what antenna power equates to 40 Amps from the power supply.

That resistor is wire wound, so may or may not be suitable for RF work.