Re: Tesla motor receiver

["Malcolm Watts" <M.J.Watts-at-massey.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Richard,

On 29 Aug 00, at 18:35, Tesla list wrote:

> Original poster: "Richard Barton" <richardbarton-at-caving5.freeserve.co.uk> 
> 
> Hi all
> 	Further to my idea about building a tesla receiver
> to power a motor.... I've been looking through the CSN's
> and it seems that the receiver should be, in itself, a replica
> of a tesla coil, but working in reverse, whereby what is
> normally the secondary, is employed as a primary, being
> connected to an antenna, and the normal primary becomes
> the secondary, thereby converting the high voltage and low
> current, to a low voltage and high current.
> Am I correct in this ?

I did this once with a small bank of torch bulbs connected in 
series with a secondary of a few turns that was wound over the 
centre of a resonator. I had to get the coupling as tight as I 
could to a small portion of the resonator while not loading it 
too much overall. Much the same thing as a crystal set.

> My idea was to generally try and discover if I could place
> my receiver in fairly close proximity to my coil, and simply
> tune roughly to the output frequency, using a variable cap
> in the receiver, then rectify the signal and feed it to a tiny
> D.C. motor. The problem is, however, that it would still
> be R.F., so I think we would need to build this miniature
> coil (secondary and primary) as Tesla did.
> But how do we lower the frequency back down to a rate
> that a diode can handle ?

Don't need to. LEDs can do the job, schottky diodes, fast and 
ultra-fast power diodes, germanium, and probably some rather 
ordinary power diodes as well not to mention the 1N914. Fast 
recovery is the key. 

Regards,
Malcolm