power for spinning led's (dc motor with power transmitter)

Permanent magnets on the outside, coils on the inside, some diodes for rectification -- voila! You have a generator.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Hi Tim

That sounds sweet, so i suppose i lookup some generator examples (which i have been doing already), and just try to model something around that ... Any tips or sites which offer some solid/tested examples or ill just have to spend a few hours at the bench after ordering a bunch of different kinds of magnets.

How about using electro-magnets on the outside (fixed) portion, presumably this would provide a stronger magnetic field than any earth magnet ?

Alex.

Presumably you could add your own slip rings onto the motor shaft where its outside the casing.

Or if youre clever about it, use 2 motors. The drive motor runs at

3600rpm, and direct drives the spindle of the generating motor mounted on the LED assy. You now have 2 sources of resistance to movement: the generator, and the wind resistance on the LEDs. I dont know if you cuold approximately balance the 2, but if so you'll get 1800rpm LEDs and an 1800rpm generator both running off a 3600rpm drive motor.

I havent tried it, no :) But if it is workable, it'd be elegant.

NT

Presumably you could add your own slip rings onto the motor shaft where its outside the casing.

Or if youre clever about it, use 2 motors. The drive motor runs at

3600rpm, and direct drives the spindle of the generating motor mounted on the LED assy. You now have 2 sources of resistance to movement: the generator, and the wind resistance on the LEDs. I dont know if you cuold approximately balance the 2, but if so you'll get 1800rpm LEDs and an 1800rpm generator both running off a 3600rpm drive motor.

I havent tried it, no :) But if it is workable, it'd be elegant.

High efficiency LEDs, eg ultrabrights, would help with the balance.

Just realised, a zener would help the LEDs get upto speed faster, as any LED underspeed = genny overspeed, which would be shorted thru the zener.

And of course theres no reason the genny must do 1800, it might do 400 and the LEDs 1800 etc.

NT

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Slip rings.

http://www.polysci.com/SlipRings/Commsliprings.html

On 14/01/2006 the venerable Quack etched in runes:

Presumably your LED's and MCU's are mounted on a PCB. Why not also mount a motor on the PCB to act as the spindle and then drive the whole assembly with a belt drive from a fixed external motor. That way the axis motor can be used as a generator and power all of the electronics on the PCB.

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John B

Delete \'spam blocker\' to reply direct

Search for a circular transformer(data and power). Or power only,with data generation on the rotating platform. Last solution use copper brush on rings.

Hi John,

I have been looking into sliprings, and have contacted over 15 manufacturers and can not find anything suitable, of the vendors/manufacturers that replied, they all say that 1800rpm and 24/7

100% duty cycle is not reliable and not long lasting and also quite expensive and requires constant maintenance as the brushes wear out.

So i am looking for a contactless solution.

As for data, i plan to use infra-red or rf.

Thanks though :) ill check out that link.

Alex.

How much current will need to be transferred ??

Transformer technology is not new, but the efficiency would be very low.

good luck

If this were a "money-making" product, then a slip ring would not be too costly.

Not getting it done would be too costly.

donald

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How much power do you have to transfer and, assuming 120V 60Hz on
the input side, what do you need on the output side (AC-wise) in
terms of voltage and current?

About 20 years ago I did some pretty substantial power transfer thru rotating transformers... of course it was for spacecraft, so price was no object.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
 Anyone can be rude, but it takes a Democrat to be a real dirtbag.

--
Not likely roulette; he said 1800 RPM 24/7.

Try a 2-ton satellite spinning at 4RPM hanging from a crane in a test facility at Sperry Satellite Systems Division.

Made we so nervous I stood behind a steel roof support girder during all the tests.

I designed the spin motor drive ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
 Anyone can be rude, but it takes a Democrat to be a real dirtbag.

--
Oh, "of course" it was...

I did the same thing 40 years ago, _and_ sent data along with power
for use with submersible oceanographic equipment.

You'll burn up a lot of power in an electro magnet that generates as much field as a rare earth magnet. Those things are almost magic (almost -- they don't bend light yet).

You can get rare earths on the web at reasonable prices -- just google for rare earth magnet and you'll have more choices than you know what to do with.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

--
LOL, 4RPM is a _lot_ different from 1800.

You already must have some method to spin this "creature". Why not just add a small alternator with case tied to "creature" and shaft pinned?

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
 Anyone can be rude, but it takes a Democrat to be a real dirtbag.

--
What you need is a rotary transformer.  

Check out the sketch on alt.binaries.schematics.electronic under the
same subject as this thread.  If you\'d like to have me build you one
email me, but it won\'t be cheap to do. :-)