Have a look in Google at "propeller clocks" They have good ideas about
transmiting power in a motor shaft.


At 00:57 30/05/01 +1200, you wrote:
>Hi all, perhaps someone can help with a wee power problem. I've
>got a circuit board mounted on a motor shaft. The circuit is there to
>measure the movement of an escapement mechanism (kind of
>like a governor) as the shaft turns from 100 to 3500rpm. The
>circuit itself is not a problem, I've managed to attached a small
>slider pot to the escapement and it's measuring OK with an ADC.
>What I'd like to do is induce power to the circuit using some kind
>of magnet/coil system. I need around 15mA at 6VDC. A possibility
>is to use a 7-segment LED (synched with the rotation) to indicate
>the escapement movement, hence the power requirement. Using
>batteries is not really an option because of the duration of the
>measurements and particularly if the LED idea goes ahead. I've
>got plenty of envultured materials - strong HDD magnets and
>more scrap transformers (enamelled wire of all gauges and
>laminate cores) you can shake a stick at. I thought I may be able
>to attach a small DC motor to the main motor's shaft as a
>generator but that's proved too tricky because of space limitations.
>So, any ideas on the most efficient way to induce power into coils
>on the PCB from stator magnets ?
>
>TIA
>
>--
>http://www.piclist.com hint: The PICList is archived three different
>ways.  See http://www.piclist.com/#archives for details.


________________________________
_______Jose Angel Navarro_______
_____welcome.to(ba/rra)janc_____
___janc(arroba)altavista.net____
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http://www.piclist.com hint: The PICList is archived three different
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