Power cable that can spin ? or other alternatives. Help Please

[Bury6690]

Hey,

1. Imagine electric device.

2. This device must have power cables, to get electricity of course .

3. This device itself, must spin.

So here is a trouble i am facing:

Device must be powered by cables in order to function. Device itself spins, it must in order for my finish product to work

How do i connect this device to power supply , without power cables being spined aka. torn apart when device itself will spin ?


Thanks for your help, A LOT !

 

[Bury6690]

I forgot to mention, this device function is not spining.
Its heating.

But it must spin Physically.

 

[davidbeach]

Slip rings won't work?

 

[Bury6690]

I dont know, i am new at working with electric components.

But this is exactly what i was asking for.

I will check Slip rings and study how they work.


Thank you very much David !

 

[Bury6690]

if there are any other alternatives to Slip rings please share your knowledge "applying to all readers"

 

[IRstuff]

Slip rings are basically one specific embodiment of a conductive rotating joint. The commutator of a brushed DC motor is another. How much power are you trying to supply? If it's low enough, there are other alternatives like inductive approaches.

Why does it need to spin?

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

http://www.engineering.com/AskForum/aff/32.aspx

 

[sreid]

Assuming the power is AC, a rotary transformer would work.

 

[MacGyverS2000]

Here's an example of sliprings in the "real" world... the plug rotates (and, it seems, can also catch on fire ):

http://www.amazon.com/Belkin-6-Outlet-Commercial-Protector-Rotating/dp/B000JV3CKA/

Dan - Owner

http://www.Hi-TecDesigns.com

 

[ScottyUK]

Stationary DC field and a shaft-mounted rectfier if your load can handle a DC supply. You can transfer pretty much as much as the prime mover can deliver using this method. What is driving the rotating element?

 

[stevenal]

Point 2. The use of an on-board battery or generator would allow the device to get electricity without cables. Might also be able to generate heat without using electricity.

 

[MikeHalloran]

Does the device need to spin continuously without limit?
I.e. if the spin is limited to a couple of revolutions, like a car's steering wheel, a clockspring conductor, or just a dangling loose cable, might be sufficient.

(Clocksprings as used in cars today are a mature product.
The early versions were subject to many failures.
Do not underestimate the real cost of developing your own.)

<tangent>
Some friends of mine were associated with a windmill, designed by Grumman in Bethpage, NY, and installed near Potsdam, NY.

Grumman included mercury-wetted sliprings to allow free rotation. Mercury freezes solid at -40F or so.
Does it ever get to -40F in Bethpage? No, never.
Does it ever get to -40F in Potsdam? Yes, every damn year.

While they were repairing the damage from the frozen sliprings, my friends noticed that the ropes used for manually yawing the generator didn't get kinked, suggesting that the generator head had rotated a lot, but never farther then +/- one revolution from its initial position.

So the second iteration replaced the sliprings with long cables dangling loose inside the tower, secured only at top and bottom.

</tangent>

Mike Halloran
Pembroke Pines, FL, USA

 

[btrueblood]

<tanh>

We once instrumented a part being cut on a lathe with strain gages, to monitor stresses in a critical part while turning. We looked at a lot of alternatives, but to keep the signal as noise-free as possible, used a 10' length of cable strung through the tailstock and held at the connection to the signal processing equipment. We would turn on the lathe and start cutting, knowing we had several minutes before the cable would wind up to the point of breaking (roughly 1000 revolutions IIRC), we only needed 200 or so turns to perform the cutting operation and so had plenty of safety margin. Then just reversed the lathe after each run to unwind the twisted cable. Worked like a charm.

</tanh>

 

[Compositepro]

Heat will transfer across an air gap, so the heater does not have to rotate in order to heat a rotating part. An electric resistance heater will rise to whatever temperature is required dissipate the input power. I've seen this work very effectively to heat rotating rollers from the inside with no slip rings. The roller temperature was measured by a stationary thermocouple that stuck into a groove in the side of the rotating roller.

Other options are induction heating, and heating with a flame or hot air blowing on the rotating object.

 

[VEBill]

A concept for your back pocket.

The heated steering wheel in my car is powered by a DC-DC converter. The purpose is to increase the voltage and reduce the current being transmitted through the slip rings or whatever they're using.

In other words: You can, if it helps, fiddle with the voltage / current ratio to cross the rotating gap. If required, you can fiddle it back on the other side.