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Re: Fw: frequency (fwd)

Trent

A 'reso cap' is a capacitor that will resonate with the secondary of your HV
supply transformer at the mains line frequency. This causes resonant rise - the
capacitor will charge much more quickly - some people say that it 'sucks' more
power from the transformer. This generally applies more to current limited
transformers such as neons or Oil burner ignition Xfrmrs. The impedance is
simply the faceplate output voltage divided by the faceplate output current.
The reactance of your cap (1/(2*pi*f*C)) should match this where f is line freq
in Hz, C is capacitance in Farads.

all the best

Alex

Tesla List wrote:

> Original Poster: "Trent" <trent-at-iex-dot-net>
>
> Hello Alex,
>
>   Thanx for your response.  Can you tell me what a "reso cap" is?
>
> Best regards,
>                               Trent
> -----Original Message-----
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
> Date: Saturday, April 17, 1999 6:21 PM
> Subject: Re: Fw: frequency (fwd)
>
> >Original Poster: Alex Crow <user-at-alexcrow.clara-dot-net>
> >
> >Trent
> >
> >BPS with a static gap can go over 120bps at 60Hz mains freq. If the cap is
> >small - impedance at 60Hz higher than the HV tranformer secondary (ie less
> than
> >resonant size), it will charge up to the breakdown voltage of the gap in
> less
> >than one half-cycle, and thus you will often get more than one bang. A
> resonant
> >cap may also deliver greater than 120bps due to the voltage rise it
> produces.
> >Often with a reso cap you turn *down* the input volts to get back to 120
> again.
> >Larger cap sizes will, of course, take longer to charge up and then you can
> get
> >lower break rates.
> >
> >As for rotary gaps, I'm not an expert. All I know is that a sync rotary
> gives a
> >much more stable break rate, is generally better quenching and more
> efficient,
> >and stresses your components less. You can also adjust the phase of firing.
> >
> >Alex
> >
> >
> >
> >
> >
> >Tesla List wrote:
> >
> >> Original Poster: Tesla List <mod1-at-pupman-dot-com>
> >>
> >> >---------- Forwarded message ----------
> >> >Date: Thu, 15 Apr 1999 12:56:53 -0500
> >> >From: Marius Grigoriu <compwiz-at-stratos-dot-net>
> >> >To: Tesla List <tesla-at-pupman-dot-com>
> >> >Subject: Re: frequency
> >> >
> >> >Tesla List wrote:
> >> >
> >> >> Original Poster: "Trent" <trent-at-iex-dot-net>
> >> >>
> >> >> Hello All,
> >> >>
> >> >> Q:  Is it possible to have an input frequency greater than the 60
> cycles
> >> going
> >> >> to the spark gap/primary, and if so, how?
> >> >>
> >> >> Thx,
> >> >>           AT
> >> >
> >> >Again, I am posting to learn, so if I'm wrong, don't get mad :)
> >> >
> >> >The whole idea of the spark gap and capacitor is to convert those 60 or
> 50
> >> cycles
> >> >to RF current so it can resonate with the secondary. If you have a
> current
> >> source
> >> >of the right frequency, you should be able to take it directly to the
> >> primary,
> >> >skipping the gap.
> >> >
> >> >Am I correct in my statments?
> >> >Marius Grigroiu
> >> >
> >>
> >> Dear Marius et al,
> >>
> >>   Hmmm...your question is interesting and somewhat akin to what I am
> seeking
> >> to understand; however my aim is NOT to eliminate the spark gap as it is
> the
> >> source of the damped wave (DW) oscillations I feel are important in my
> work.
> >>
> >>   I am working with electromedical devices and am attempting to
> understand
> >> the relationship between the frequency of the incoming voltage/current
> >>  typically 60 cps) with regard to the charging of the capacitor and the
> >> breaks per second (bps) of the spark gap.  It appears that the maximum
> bps
> >> with a static gap are limited to 120.
> >>
> >>   This limit doesn't appear to apply to a rotary gap.  My questions:  How
> >> does the use of a rotary gap effect the charging of the capacitor, the
> break
> >> down of the gap and the power transfer across the gap, when subject to
> the
> >> typical incoming frequency?  Aren't we sacrificing power by increasing
> the
> >> bps?  Is it possible, say by using a higher frequency input, to increase
> the
> >> charge to the capacitor, thereby increasing the power across the gap,
> >> resulting in greater effectiveness of the system?
> >>
> >>   I'm looking at the possibility of using a 400cps input in an attempt to
> >> realize greater efficiency from a rotary gap system; any input/feedback
> is
> >> welcomed.
> >>
> >>   Thanx and best regards,
> >>                                                   Trent
> >
> >
> >