Rotating electrical contact teardown
Added 2023-05-22 23:17:54 +0000 UTCA low voltage and low current means of transferring power to a rotating object. I'm not sure of the original intended application, but the suggestions of robotics and CCTV seem fairly plausible, although I'm not sure I'd trust them for a control or video signal.
The listing suggests they are good for 220V at 2A, but I'm inclined to disagree with that. If you want mains at decent current AliExpress has sets of chunky brass rings with carbon brushes.
https://www.youtube.com/watch?v=XTPcSdeAd2Q
Comments
Ah yes, dynamic tracking on Video 2000 machines from Philips/Grundig - no tracking lines regardless of what speed the tape was running at. I seem to recall seeing domestic VHS machines using this tech., but that was way too long ago to remember the specifics..
Gordo
2023-06-12 17:15:45 +0000 UTCSlip rings were also used to provide high voltage to piezoelectric actuated heads in VCRs and VTRs that were auto-tracking: they would adjust the helical tracking when paused so the picture would be solid.
Blargity Blarg Blarg
2023-06-08 09:15:09 +0000 UTCFor cameras on robots etc., the solution would be to transfer power via sliprings to supercapacitors powering the camera and couple the signal wirelessly. That way, if you knock the robot's head off with a baseball bat, it can still see to target you with its lasers
Gordo
2023-06-04 20:14:36 +0000 UTCThe earliest helical scan video recorders used not dissimilar sliprings to connect the video heads on a drum rotating at 1800rpm to the rest of the circuitry - head playback signals are in the order of microvolts. I seem to recall each "brush" was doubled up to reduce bounce & drop-out. Later video recorders used rotary transformers to achieve this..
Gordo
2023-06-04 20:12:07 +0000 UTCThere was a Nuts and Volts Magazine article a year of so ago where a guy built the Ferris Wheel from a vintage Erector set and added LED strips on all the spokes using one of those. Very cool idea for illuminated rotating toys!
George Cohn
2023-05-25 03:11:24 +0000 UTCAs Nani mentioned above, it could be viable for POE type applications where there will potentially be error correction applied to the data.
Big Clive
2023-05-24 01:17:40 +0000 UTCYeah, I wouldn't use it on something that rotated fast continually, although it was well greased.
Big Clive
2023-05-24 01:16:56 +0000 UTCThat does make sense.
Big Clive
2023-05-24 01:15:58 +0000 UTCThat would depend on the application.
Big Clive
2023-05-24 01:15:20 +0000 UTCIt's usually soldered in lengths of 500mm, but it is possible that they used up shorter sections.
Big Clive
2023-05-24 01:15:00 +0000 UTCGold plated contacts at 250 rpm? Haha yeah won't take long to wear through, especially with 2A running through it.
Mike Page
2023-05-23 20:21:02 +0000 UTCI would imagine it is possible to ship control data across as long as you protect it the same way you would with a radio link prone to interference bursts. I think CD uses similar methods to overcome brief losses of data.
Mike Page
2023-05-23 20:18:44 +0000 UTCI took apart a pan-tilt-zoom security camera and the input PoE ethernet cable went through one of these. All the camera electronics and motors were on the far side, electrically, from one of these. The camera had been fried by lightning. The ethernet cable had these entry and exit burn holes through the outer cover.
Nani Isobel
2023-05-23 16:38:15 +0000 UTCI certainly wouldn't be putting much in the way of power through those contacts. I can see how one half is held static with the mounting flange, but how do you attach something to rotate the other half. Some sort of drive belt?
AlfaGuy
2023-05-23 16:14:09 +0000 UTCSpeaking of stuff on Ebay that looks like factory rejects. I recently bought some 5630 LED tape. As i am looking at it, i can see what looks like about 6" long pieces soldered together under the gel covering. It looks like somebody at the factory took all the short scraps and soldered them together to be 5 meters long then ran them through the gel machine. That is a first for me seeing that!
Matt Larson
2023-05-23 13:11:12 +0000 UTCThat IS neat. Thanks Big Clive. Those ratings are Very generous!
Dave Frederick
2023-05-23 01:47:40 +0000 UTC
