Re: Lighting incandescent lamps with TC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<davep-at-quik-dot-com>
> 
> > All,
> 
> > I was wondering how many of you have tried the
> > experiment where you cause an incandescent lamp to
> > glow from current coupled by induction, by connecting
> > a wire loop across the contacts of the bulb.  I tried
> > this using a flashlight bulb, wire loop and approached
> > (as close as I dared without being tagged by
> > streamers) my running 6" coil.  Nothing.  Not even the
> > slightest glow from the filiment (spelling?).
> 
>         close.
>         filament.  8)>>
> 

>         Lighting a filament (a demo Tesla used to do) I've
>         not tried.  The physics are simple:
>                 need to get enough current into the filament.
>         (Tesla used to use Very heavy copper, i've heard
>         tales of bus bars....) to demonstrate that The Freqs
>         are Different and the behaviour is different.)
>         Random thoughts:
>                 Pick a LOW CURRENT lamp (measure them)
>                 Flashlight lamps are high current FOR THE
>                 EQUIVALENT WATTAGE.
>                 Try a multiturn coil.
>                 Fat Wire (current operated device).
>                 Build a series resonant circuit AT THE COIL
>                 freq?
> 
> > Does anyone have any ideas as to what the problem is?
>         Not enough current.
> 
>         (Filaments are very nonlinear.  Might be Just
>         Under incandescence and Not Quite There.)
> 
>         best
>         dwp

	I can't understand the problem, as it should be easy to burn out a
filament - after all you have at least several hundred watts to play
with!  I have an absorption wavemeter (series tuned circuit comprised of
inductor, variable capacitor, and bulb filament) here which I built for
measuring appropximate TC operating frequencies.  The indicator is a 60
ma, 2 volt pilot lamp shunted with a small inductor.  I can burn out the
bulb if I get too close to the primary of a 30 watt miniature coil I
built a while back, and with a bigger coil I need a separation of feet. 
Interestingly enough, because of the high peak power/low duty factor
nature of the spark signal, I can get sparking [voltage breakdown]
between the plates of the 0.001 mfd variable capacitor (old Cardwell ca
1922) long before the filament goes.

Ed