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Scoped? primary
----------
From: chris.swinson [SMTP:chris.swinson-at-zetnet.co.uk]
Sent: Monday, August 17, 1998 2:43 PM
To: Tesla List
Subject: Re: Scoped? primary
hi Terry, + All,
I don't think my probes will come to much harm. At work we repair TV's and
use just a ungrounded scope to measure the 25Kv flyback output.
I only went via 5 meg just to be on the safe side, If I hadn't I would not
be able to see the wave as it would be to high to fit on the screen.
There's no way I'd connect it to the secondary HT, But the primary should be
ok enough.
I was in the filed when I touched the scope lead ground, though I did not
have the secondary in place, so I suppose that limited it a bit. I actaully
wrote a quick program to draw the wave, If any one wants it then I'll upload
it to my site. I must point out that the last few cycles are a little wrong
but you can get the idea.
All the beST,
Chris.
chris.swinson-at-zetnet.co.uk
www.users.globalnet.co.uk/~mega01/ <--- moved site to...
www.users.zetnet.co.uk/mega.disczine/
-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: 'Tesla List' <tesla-at-pupman-dot-com>
Date: 17 August 1998 15:09
Subject: Scoped? primary
>
>----------
>From: terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
>Sent: Sunday, August 16, 1998 5:43 PM
>To: tesla-at-pupman-dot-com
>Subject: Re: Scoped? primary
>
>Hi Chris,
>
>
>At 10:02 PM 8/16/98 +0100, you wrote:
>>Hi all,
>>
>>I found that you can connect you scope to the primary of your coil without
>>blowing the thing up.
>>
>>What I did was to se my coil up using the 8th turn of my primary, as I
have
>>14 turns on this one, I took the free end and connected about 5meg onto it
>>and then went to my probe. I didn't connect the ground I left it
floating.
>>I tried to move it and I got xapped so I ain't a good idea anyway.
>
>The free end is probably at twice the potential of the primary circuit due
>to transformer action with the tap you mention. Be absolutely sure the 5
>meg resistor will withstand that voltage. The ground lead should be
>grounded by the scope's ground. You probably graounded yourself when you
>touched it and drained you body's charge (you were in the E field of the
>coil). I assume you have a 10:1 probe or something like that. Beware that
>you may damage the probe.
>
>>
>>I sawthe RMS power at about 10Kv at the resonat frequency. I forgot to
>>write down the frequency, Huh. I also saw the huge surge of the coil
which
>>appeard right on top of the RMS wave. Rather odd seeing 2 waves as 1.
>
>The RMS was from the primary transformer charging. The surge was due to
gap
>firing and all the "stuff" from the coil.
>
>>
>>The first surge was off the screen, and about half way down that cycle it
>>cam back on my screen and then got smaller and smaller until it flat
lined.
>>
>>This is a clear indication of the cap loosing X% each cycle of the
resonant
>>frequency. As there are losses each cycle, this clearly shows up and It
was
>>really clear as well to see what was going on.
>>
>>Just thought I'd mention it.
>>
>>
>>
>>All the beST,
>>Chris.
>>
>>chris.swinson-at-zetnet.co.uk
>>www.users.globalnet.co.uk/~mega01/ <--- moved site to...
>>www.users.zetnet.co.uk/mega.disczine/
>>
>>
>>
>
>You may want the check out my field probes at:
>
>http://www.peakpeak-dot-com/~terryf/tesla/experiments/experiments.html
>
>They give great information about your coil and are far safer for your
>equipment.
>
> Terry Fritz
>
>
>
>