Output Voltage vs. Firing Rate (fwd)

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Output Voltage vs. Firing Rate (fwd)
From: Tesla List <tesla-at-stic-dot-net>
Date: Wed, 12 Aug 1998 20:31:26 -0500
Approved: tesla-at-stic-dot-net

----------
From:  FutureT-at-aol-dot-com [SMTP:FutureT-at-aol-dot-com]
Sent:  Wednesday, August 12, 1998 6:43 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: Output Voltage vs. Firing Rate (fwd)

In a message dated 98-08-11 22:15:24 EDT, you write:

<< 
 >> Test 1:  Using this 42" spark TC with sync-gap, the sparks easily hit 40",
 >> at 640 watts (wallplug) as measured with a wattmeter.

>I would take a look at what is the wattmeter actually measuring.
>With small ballast inductance in a potential transformer, the input
waveforms,
 >specially of the current, can be far from sinusoidal, and a wattmeter
designed
>for 60 Hz operation may give wrong results.

> Antonio Carlos M. de Queiroz
  >>

Antonio,

At the 640 watts using 120BPS, I've carefully checked out the wattage
using a thermocouple type ammeter, checked the power factor, then
compared, etc.  I found the wattmeter to be accurate within a few 
percent.  At the higher break rates, I did not do this comparison, so
there could be more error.  I did do a quick and dirty test by placing
a 5amp somewhat slow-blo type fuse in my ac (240V) mains, and it
blew out after awhile while my ammeter read 7amps.  So even with
worst case errors, the TC must be drawing a minimum of 1200 VA,
compared with the wattmeter reading of 1500 watts, and ammeter
reading of 7 A, (1680 VA).  It would seem that the TC is drawing
at least about double the power at the higher break rates.  

John Freau