[Prev][Next][Index][Thread]
Freaky frequency
From: DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: Wednesday, June 18, 1997 11:37 PM
To: Tesla List
Subject: Re: Freaky frequency
TO: Erik Hennix
50 ma. of drive current for a .022 MFD cap is not enough. You need a
minimum of 120 ma. of drive current (voltage not as important if in the
6-12 kv range) to drive this system. Then you can use your larger terminal
and get some longer sparks.
Hope this points you in the right direction.
DR.RESONANCE-at-next-wave-dot-net
----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Freaky frequency
> Date: Tuesday,June 17,1997 6:16 PM
>
> Subject: Freaky frequency
> Date: Tue, 17 Jun 1997 08:20:08 PDT
> From: "Erik Hennix" <mr_white-at-hotmail-dot-com>
> To: tesla-at-pupman-dot-com
>
>
> Hi everyone!
>
> I've been getting some strange results while tuning my
> coil. I'll first state the specifics of my system.
>
> Secondary coil:
> 11cm PVC pipe wound with approx 810 turns
> of 0.6mm magnet wire. About 37 turns per inch.
> Sealed with clear plastic laquer.
>
> Primary coil.
> Cone shaped with 60 degrees banking and 15 1/2
> turns of 1/4" soft copper tubing. The hypothenuse being
> 22.5cm in length and the inner (lowest) turn 15cm in
> diameter.
>
> Capacitor:
> Vertical plate type made of polyethene and aluminum foil
> and immersed in motor oil. I've measured the capacitance
> (using line voltage and a mA meter) to 0.022uF.
>
> Power supply:
> Two 3920V 50mA neons in series giving 7840V 50mA (390VA).
> Puny -I know.
>
> Spark gap:
> RQ style cylindrical gap with 5 electrodes spaced as wide
> as possible with a 17W cooling fan.
>
> RF Ground:
> Three metal rods 65cm in length 1.5cm in diameter 60cm in
> very wet soil. Connected to base of secondary via a 50cm
> long heavy cable.
>
> And of course a line filter, RF choke, safety fuses.
> BTW line frequency here in Sweden is 50Hz
>
> While tuning I've been getting the longest spark using a
> metall ball, 2cm in diameter, as a discharge terminal. With
> this the coil tunes at 15 1/4 turns. I also tried using a
> 7.5cm sphere which reduced the spark length considerably.
>
> This seems very strange to me since I've calculated the
> inductance of the primary coil to about 57.5uH. With
> 0.022uF of capacitance this should give a frequency of
> about 142kHz.
>
> 141kHz for a 2cm sphere?!!
> That can't be right.
>
> What's going on here?
> Is there something wrong with my calculations?
> Maybe the the input power is too low to produce long sparks
> from larger discharge terminals.
>
> Hope someone can help me out here.
>
> Cheers,
>
> Erik.