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Re: Why does top capacitance work? (fwd)
---------- Forwarded message ----------
Date: Sat, 1 Mar 1997 00:03:53 +0000
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
To: Tesla List <mod1-at-pupman-dot-com>
Subject: Re: Why does top capacitance work? (fwd)
At 04:00 AM 2/28/97 +0000, you wrote:
>
>
>---------- Forwarded message ----------
>Date: Thu, 27 Feb 1997 08:09:05 -0800
>From: "David E. Sharpe" <sccr4us-at-erols-dot-com>
>To: Tesla List <mod1-at-pupman-dot-com>
>Subject: Re: Why does top capacitance work? (fwd)
>
>Tesla List wrote:
>>
>> ---------- Forwarded message ----------
>> Date: Thu, 27 Feb 1997 00:48:41 +0000
>> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> To: Tesla List <mod1-at-pupman-dot-com>
>> Subject: Re: Why does top capacitance work? (fwd)
>>
>> At 05:29 AM 2/26/97 +0000, you wrote:
>> >
>> >
>> >---------- Forwarded message ----------
>> >Date: Tue, 25 Feb 1997 20:20:30 -0800
>> >From: Greg Leyh <lod-at-pacbell-dot-net>
>> >To: Tesla List <mod1-at-pupman-dot-com>
>> >Subject: Re: Why does top capacitance work? (fwd)
>> >
>> >Ed Sonderman wrote,
>> >>
>> >>
>> >> Ed,
>> >>
>> >> I was curious if you noticed where the extra 3kVA power went when you
>> >> increased to 7kVA. Did something get 3kVA hotter?
>> >>
>> >> -GL
>> >> >>
>> >> GL,
>> >>
>> >> I measure the power into the system by monitoring the pole pig primary
>> >> current and voltage. The only thing I can tell you for sure is the watts
>> >> consumed. As to where they went, I am not sure, maybe into the spark
gaps?
>> >> Maybe it gets reflected back into the primary and is lost as radiated
>> >> energy?
>> >>
>> >> Ed Sonderman
>> >
>> >
>> >Ed,
>> >
>> >At this point, it seems crucial to know _how_ the extra power was applied to
>> >the coil. Did you increase the primary voltage (longer sparks), or increase
>> >the gap rate (thicker, faster sparks above ~300 PPS) ??
>> >
>> >-GL
>> >
>> >------------------------------------------------
>>
>> Ed & GL -
>>
>> Finding the true wattage input to a Tesla coil is impossible without very
>> elaborate instrumentation. The power is voltage times current times
>
><<SNIP for Chip>>
>
>I have an OPTOISOLATED solid state wattmeter which measures true average
>instanteous power which I have been using on a small (1kVA) magnifier
>very successfully for the past 18 mo. It consists of a NEC 4 channel
>(16pin DIP) optiosolator in a bridge configuration, driving a 741
>op amp as an integrating multiplier (via the logarithmic effects
>of the optocouplers).
>
>The circuit was in EDN several years ago, is fairly accurate +/-
>5% at 1.3kVA, and is CHEAP :^) , less than $50. I believe
>accuracy can be improved further, I just don't have the time or
>inclination with work overtime etc. to pursue yet.
>
>I am presently increasing capability for a 7.5-10kva?? magnifier
>I am building. If interested contact directly
>
>DAVE SHARPE, TCBOR
>>
>> I would be interested in hearing comments on how the true wattage input
>> could be metered so we can compare the classical TC with the magnifier.
>>
>> John Couture
>
>--------------------------------------------------
Dave -
I was pleased to hear of someone on the Tesla List who had actually built a
true wattmeter. I am a retired EE and several years ago I ran into this
problem when I specified controls for variable speed motors. The motors were
for a water treatment plant that used several 60 to 200 HP motors. The speed
was controlled by varying the frequency pulses. The utility used standard
meters and several problems arose. There are many of these variable
frequency drives (VFD) around now and utilities use electronic metering.
Large computer systems with switching power supplies are also a metering
problem. Large Tesla coil systems connected to standard meters may not be
correctly metered. However, Richard Hull and a few other coilers are
probably getting a bargin.
Will contact you directly.
John H. Couture