Idea for DIY 1-ohm resistor

[Shadetree Engineer]

Well, I suppose I ought to attempt some explanation of what's going on here. I was goofing around and playing with some magnets and otherwise just killing time when I decided to cut a small piece out of an aluminized mylar 'emergency blanket' to see how much it would take to get one ohm. Turns out it doesn't take much, provided you get a good enough connection.

The rig pictured here is a pair of razor-blades acting as a spreader bar, with a napkin under the mylar to distribute the load as evenly ( well somewhat evenly) along the blades contact area as possible.

Some weights hold a set of test leads firmly on top of each blade, and a multi-meter is set to read tenths of an ohm. I adjusted the heck out of the blade spacing until I got close to one ohm exactly, then took this picture.

I have no idea as yet what the load capacity might be for the mylar, the blades could be replaced with something more substantial. Maybe the mylar should be a long narrow strip with brass strips along each long side, clamped into place.

But for the fun of it, I really ought to come up with a way to datalog the voltage across the blades, and just slowly crank-up some power through this. Any ideas on datalogging on the cheap?

 

[anselm]

Interesting, but not teribly practical, it seems.
Wouldn't it be easier to just use a really long and thin piece of wire? :thinking:
http://www.cirris.com/testing/resistance/wire.html
Anyway, +1internetz for practical experimenting and measuring instead of just chatting and yakking.
:gj:

 

[Shadetree Engineer]

Interesting, but not teribly practical, it seems.
Wouldn't it be easier to just use a really long and thin piece of wire? :thinking:
Anyway, +1internetz for practical experimenting and measuring instead of just chatting and yakking.
:gj:

Yeah, probably easier to use wire. But I think this is more fun!

But the one ohm experiment was actually me getting sidetracked, as usual!

I have a set of magnets out of a hard-drive, I'm about to see what happens if I suspend an eight-ohm piece of this mylar between the magnets while connecting the mylar to my stereo.

 

[Bionic-Badger]

Pretty impractical considering that 1 ohm resistors are cheap. However, what you've made there might be cool for a large mechanical variable resistor, and you could even apply that hardware towards making custom capacitors. In that respect, keep on truckin'!

 

[Shadetree Engineer]

Pretty impractical considering that 1 ohm resistors are cheap. However, what you've made there might be cool for a large mechanical variable resistor, and you could even apply that hardware towards making custom capacitors. In that respect, keep on truckin'!

Well, that makes two votes for 'impractical, yet cool' so lets just call it engineering art. Maybe if someone's thinking of how to make a pretty looking steampunk load tester, or other device. But the amount of blade movement to get a tenth of an ohm change is really small, so I'm thinking it might be better off for a higher value of resistance if it's to be a variable device.

 

[BudK]

Unfortunately that stuff burns like Thermite . I nearly set my back porch on fire when using it to insulate a mash tun while homebrewing . Went through an entire 20 # Co2 extinguisher trying to put it out . Ended up throwing the whole flaming mess out in the snow & it still kept burning . I'd say keep it low amperage .

 

[Shadetree Engineer]

Unfortunately that stuff burns like Thermite . I nearly set my back porch on fire when using it to insulate a mash tun while homebrewing . Went through an entire 20 # Co2 extinguisher trying to put it out . Ended up throwing the whole flaming mess out in the snow & it still kept burning . I'd say keep it low amperage .

Hey! It's coated with aluminum! I hadn't thought of that. Awesome, I got a whole new line of ideas!

 

[Shadetree Engineer]

Hey! It's coated with aluminum! I hadn't thought of that. Awesome, I got a whole new line of ideas!

Maybe I need thicker stuff, mine goes out too easy. And it burns real slow. Darn.

But don't let the melting part get on your thumb! That stings a little bit...

 

[BudK]

As I recall, it may have been gold in color on one side .

 

[lasersbee]

I've done similar experiments with Black anti-static foam and
pencil graphite...
Nice experiment..... But I also agree....
Low currrent capabilities and large surface area maske it
impractical...

Jerry

 

[Shadetree Engineer]

As I recall, it may have been gold in color on one side .

I just happen to have some party film that's gold on one side, silver on the other. Neither side conducts, but a quick test just now shows a much better flammability. I think this is the stuff you were using, it was about three times harder to blow out! And stinkier too!

 

[Shadetree Engineer]

I've done similar experiments with Black anti-static foam and
pencil graphite...
Nice experiment..... But I also agree....
Low currrent capabilities and large surface area maske it
impractical...

Jerry

Yup, I'm starting to think it's gonna get shelved for use in something completely different.

Meanwhile my single-pass magnetic-drive idea was very non-functional. I need to learn how to etch this stuff so I can draw a circuit onto the film. Mounting the magnets on a arbor spun with a drill produced about a thousandth of a volt when held above a strip of the mylar. No go with that idea. Maybe a little less coffee before midnight?:drool:

 

[lasersbee]

Hey... If we (humans) never thought outside the box...
We would still be living in caves...

Jerry

 

[Shadetree Engineer]

Hey... If we (humans) never thought outside the box...
We would still be living in caves...

Jerry

caves lined with gold party film!