o/t electronics

[dombanks]

ive been trying to search about for a solution to a problem at work but im not sure where to start or what it may be called so perhaps one of u lot might know?

bear with me as i try to explain it.

i need to get power to the top of a rotating spindle so whatever is attached to the top can have voltage and current to operate some small electronics.

an example.

say i had a simple cd player and instead of a cd i had a disc that had very basic electronics on it. i need to power these somehow,

a battery on the disc is out of the question

i was thinking of some sort of brush type thing (abit like the way a scalextric car works) at the bottom of the cd/spindle but what are these called? who makes them?

what about some sort of bearing type device

also wont they be a bit noisy (electrically) and inefficient.

how do you transfere power onto a spinning rod?

[bhouse]

Sounds as if you need a slip ring. We've come across these people but have not used their products directly.

Brian

[ptownsin]

Much more complicated solution...

Induction

Turn the disc into a generator with coils, magnets stationary, and rectify and smooth the generated current on the disc.

Down sides are the power stops when the disk stops and the added complexity and components on the disk.

Just an Idea..

[Man On The Clapham Omnibus]

The induction idea is likely to be 'cleaner' - noise can be dealt with but it's all a matter of weight and cost. Induction could be done with the disc static surely? Induction hobs don't spin.

[dombanks]

induction is one method we have considered, the disc has to spin its integral to the device.

what sort of power do you think can be generated using induction, the electronics are basic, i was using a surface mount resistor as a heater (control of temp is not needed just either cold or hot) and thats about it.

thanks for the slip ring thing and link it gives me a direction to head in.

[ptownsin]

Induction just needs a changing magnetic field.

Either like an induction hob i.e. AC coils creating a alternating field from AC electricity or by moving the coils past static magnets like a generator (spinning).

Do you know the power/heat requirements?

If all you need is a heater then the AC off the coils might not need to be rectified/smoothed, making things much simpler.

[tex]

didnt one of the f1 teams have a disc type kers system? BMW? Right at the start of development? Is there anything there of use?

[pistonbroke]

Inductive coupling uses coils (transformer) so it has to be AC current and usually at radio frequencies so you would need some kind of  RF modulator to transmit and a receiver

For small currents perhaps model aircraft controller  transmitter with whatever receiver on the disk ?

Just a thought