From: "Terrell W. Fritz"
Date: Mon, 28 May 2001 19:31:01 -0600
Subject: Re: [TSSP] Topics on non-linear effects
Hi Paul, Capacitive voltage dividers may be the way to go. Something along the lines of the $800 Pearson: http://www.pearsonelectronics.com/Pages/Capacitive_Voltage_Divider.html Unfortunatly, there were none on E-bay... ;-) They have the advantage of being calibrated out of the box (5%) and all the thinking is done. They have 18pF of load. Most places seem to roll their own: http://www.uni-stuttgart.de/ieh/forschung/einrichtungen/v_general.jpg http://www.uni-stuttgart.de/ieh/forschung/einrichtungen/v_Teilentl1.jpg The problem is by the time you get all the electrostatic shields and terminals big enough not to arc, the load goes up too high. However, they are basic physical devices with few tricks and the outputs can be clamped heavily and such for protection. Calibration is not trivial either. I'll think on it. The plane wave antenna is another possibility but it is a wide area device. Perhaps it could be aimed through a tunnel or antenna like array to hit a small spot... I used to repair voltage dividers on 375kV power line equipment (live ==:-| ) but I don't think those types would be any good at high-frequency. Cheers, Terry At 11:37 PM 5/28/2001 +0100, you wrote: >Terry, All, > >Some preliminary notes on your CW brush discharge current >measurements. > > http://www.abelian.demon.co.uk/tssp/tfcw260501/ > >Next step would be to determine what the discharge impedance >is, and how it varies with the steady state voltage. But an >essential prerequisite is a means to reliably capture the >peak topvolts value. > >Without this, we can't establish a pattern for brush discharge >loadings, nor can we confirm ET6.12 predictions of breakout >voltage. So now would be a real good time for budding inventors >out there to get cracking. > >Cheers All, >-- >Paul Nicholson, >Manchester, UK. >--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.