electrical slip ring replacement

[GeorgeIoak]

I looking for a way to transfer 10 DC low current signals on a rotating device. The standard electrical slip rings are too expensive (several hundred dollars) and I'm trying to locate a lower cost solution.

I've come up with a plastic pipe which I slide a series of copper rings onto seperated by rubber O-rings. I then plan to place this inside another larger diameter pipe. The smaller pipe with the copper rings will fit on the inside bore of a bearing while the larger pipe rides on the outside of the bearing.

I want to place a 10 conductor cable around the larger pipe and transfer the electrical connections to the inner copper rings. This is where I am stuck. I need some way to make a good contact from the outer pipe to the copper rings and still be able to produce about 20 of these.

Any ideas???

Thanks,
Geroge

 

[nbucska]

Use a rotating xformer with AC and rectify/filter it.
The xformer consist of two pot-cores with the cross-
section "E" -- one with the static primary, the other one
the rotating secondary. The axis of the rotation is the center bar of the "E".

Use a 20-40 KHz .Maintain a reasonable airgap.





<nbucska@pcperipherals.com>

 

[GeorgeIoak]

How does this get me 10 circuits though?

 

[nbucska]

Sorry I thought 10V DC.

Well, you can supply the pover at a given frequency and superimpose on it the time-multiplexed digital signal.

Instead of superimposing, you may use LED/photodiode in the central hole.


<nbucska@pcperipherals.com>

 

[fil]

similar to the above why not try emc grounding strips onto the copper strips?
these can be cut and soldered - being beryllium? copper they should last
they could be mounted on a flat plate with sufficient pressure to contact
good luck