tesla coils & frequency
To: mail11:;-at-msd26.ENET.dec-dot-com (-at-teslatech)
Subject: tesla coils & frequency
From: "I am the NRA." <pierson-at-msd26.ENET.dec-dot-com>
Date: Mon, 15 Jan 96 15:37:27 EST
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>> Now on the tesla coil, my very basic understanding is that the coil
>>is really nothing more than an 'Antenna' wrapped around a pole.
Thats one way to look at it.
>>And as an Antenna it gives off an RF frequency based upon its capacitance.
And on its inductance.
>> Now the RF Spectrum is (according to my basic electronics book):
>> 15Khz to 30Khz VLF (Very Low Frequency)
>> 30Khz to 300Khz LF (Low Frequency)
>> 300Khz to 3MHz MF (Medium Frequency)
>> 3MHz to 30MHz HF (High Frequency)
>> 30MHz to 300MHz VHF (Very High Frequency)
>> 300MHz to 3000MHz UHF (Ultra High Frequency)
>> 3000MHz to 30,000MHz SHF (Super High Frequency)
>>Since these are all Radio Frequency's. Can the tesla coil operate
>>in all these Frequencys'?
A tesla coil can be designed to operate at any frequnvy, in theory.
In practice one of Dr Corum's students built a 'coil' at 160 odd Mhz,
Nikola Tesla generally (as near as we can tell) confined himself to
somewhere under 200 odd KHz. (It is quite possible to go to the
hundreds of MHz with spark gap technology.)
>> Or is there a upper limit to the tesla coil?
Not that i am aware of. As a practical matter, the 100s of Khz
range is easy to work with.
>The Tesla Coil is far more than an antenna. It is a resonant circuit, the
>resonant frequency of which is determined by the value of the coil in
>henries and the cap in farads,
Thats one approach to determining the resonant frequncy of a coil.
My understandaing (Corum & Corum) is that a 'helical resonatr' model
>( more like milihenries and microfarads). It may also be described as the
>point at which inductive reactance and capacitive reactance are equal.
In fact, a given 'thing' may have multiple resonant frequencies. The
experiences i have seen reported are the resonant-frequency-defined-by
-helical-resonator math are closest.
Spark. A Spark and an arc are different things.
(Roughly: An arc is quasi continuous. A spark 'stops' then restarts.
Typically this happens faster than the eye can see, in tesla coil
work. It is the need to 'stop' that makes the matter of quenching
the gap so important.
>as generated by the primary circuit of the tesla coil energizes or "excites"
>the L/C resonant circuit of the secondary, and causes it to oscillate at its
Right. However, a given 'thing' can have multiple resonant frequencies.