Re: Bad monitor discharge instructions

Current is voltage divided by resistance. So 20 kV into a short is one hell of a
lot of current for a very short time. Into 20 kohms you would initially have 1 amp
decaying exponentially to zero. Assuming 2000 pF of capacitance and 20 kohms you
would have a time constant of 40 uS. So every 40 microseconds the voltage and
current will decrease by about 67 %. It never actually gets to zero, but for all
practical purposes it is assumed to be zero after 5 time constants (200
microseconds, in this example).

Your reading was based on the response time of whatever meter you were using. I
wouldn't be trying that with a digital meter if you will be needing to use it
again, there is a very real danger of blowing out parts.

John Robertson wrote:

> For anyone that remembers the formula (or can find it) for the amount of
> current stored in a capacitor, I measured a 13 inch picture tube on
> Saturday and came up with a value of 0.001 (102). This was between the
> anode cap and the chassis that it was mounted in. The tube was not
> connected to anything else.
>
> So @ 20KV what are we talking about? I left my Nomographs sitting on the
> filing cabinet.. somewheres...
>
> John :-#)#
>
> At 11:26 PM 12/19/1999 -0500, you wrote:
> >I agree this is the best course. It will ruin the topic of my radio show, but
> >hey, that's better than crispy newbies!
> >
> >-Al-
> >
> >saint wrote:
> >
> > > I emailed the owner of the web site with the bad monitor discharge
> > > instructions to tell him conventional wisdom was that he was in error - if
> > > he wants to see them, I was thinking of forwarding the
> > > discussion from Vectorlist on his web page, with names/emails removed.
> > > Before I did so, I wanted to make sure no one objected?
> > >
> > > --- saint
> > > Build Your Own Arcade Controls FAQ
> > > http://www.arcadecontrols.speedhost.com
> > >
> > > On Mon, 13 Dec 1999, saint wrote:
> > >
> > > > I was thining about it, but didn't want to get into a flame war,
> > > > particularly since I can't speak from any position of
> > > > personal-certainty-of-knowledge...
> > > >
> > > > --- saint
> > > > Build Your Own Arcade Controls FAQ
> > > > http://www.arcadecontrols.speedhost.com
> > > >
> > > >
> > > > On Mon, 13 Dec 1999, Christopher X. Candreva wrote:
> > > >
> > > > >
> > > > > One thing this show reminded me of -- did anyone ever contact the
> > person
> > > > > with the alternate cap-kit instructions, and actually tell him his
> > > > > method of tube discharging is -- suboptimal ?
> > > > >
> > > > > :-)
> > > > >
> > > > > -Chris
> > > > >
> > > > > ==========================================================
> > > > > Chris Candreva -- chris@westnet.com -- (914) 967-7816
> > > > > WestNet Internet Services of Westchester
> > > > > http://www.westnet.com/
> > > > >
> > > > >
> > > >
> > > >
> >
> >--
> > =====================================================================
> >-= Al Warner batlzone@cyberenet.net =-
> >-= Learn how to install a Cap Kit in your video game's monitor and =-
> >-= see a whole lot more on my web page at: =-
> >-= http://www.cyberenet.net/~batlzone =-
> > =====================================================================
>
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> http://www.flippers.com
> "Old pinballers never die, they just flip out."

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