Re: [Fwd: Spark gap not firing]

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

Original poster: "Luc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ludev-at-videotron.ca>

Hi Ed, Terry, list

Tx guy for your help. Just to verified if I understand well: If I want a
cutoff frequency of 50
KHz and I use a resistance of 2 Kohms I need a cap of 1.59 nF. If I use
less resistance and
more capacitance for the same value in the equation is the curve: frequency
to db attenuation
will be stepper  ? If my coil have a resonant F of 100 KHz is this filter
good or I'll need a
cutoff F lower .

Luc Benard

Tesla list wrote:

> Original poster: "Ed Phillips by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>
>
>
>
>         The expression for the half-power cutoff frequency of a low pass RC
> filter is simply
>
>         Fc = 1/(2*pi*R*C)
>
> where Fc is in Hz at which the output voltage/input voltage ratio is
> 0.707 [1/sqrt(2)] , R is in ohms, and C is in farads.  This applies to
> the simplified case of a filter between a zero-impedance source and an
> infinite impedance load. In the case of such a filter inserted between a
> TC primary circuit and a transformer, things may not be quite so simple.
>
> Ed