From: Paul
Date: Sun, 13 Oct 2002 16:42:22 +0100
Subject: Re: [TSSP] Top Voltage
Bart wrote:
> my smaller 4.5" coil is already in place...think I'll start
> measurements with it.
Ok, I put in the details as coil ba1. The predicted mode
frequencies are 212.2 kHz and 250.0 kHz, with Fsec coming out
at 234.9 kHz, an error of -1.3%. You got 248 kHz with
the gap shorted. That's the upper mode, with an error of +0.8%.
You'll find another around 2% below 212 kHz, say 208 kHz.
f3 should be up at 849.5 kHz with the primary gap closed, and
836.6 kHz with the primary gap open.
Modeled Lsec are
Ldc: 18.84 mH (measured 18.67, model is +0.9%, ok there)
Les: 18.69 mH
Lee: 18.44 mH
All very close together because of the huge amount of toploading.
This coil must be one of the most heavily loaded that we've seen.
Fpri comes out at 223.4 kHz, so a 5% detune is predicted.
ba1: Bart's small coil,
Predicted breakout: @ 320kV, equating to 10.7kV firing volts.
Base current should be a smidgen under 12 amps peak at 10.7k Vfire.
As regards calibration, even though the probe is known good, it's
nice to get an end to end check.
--
Paul Nicholson,
--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.