Re: Fiber Optic V & A Meters

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Steve,

See this file about fiber optically coupled probes.

http://hot-streamer-dot-com/TeslaCoils/Misc/Project_color.pdf

Beware some "cheap" fiber optics stuff has a very limited working distance.
 Red LEDs don't go through plastic fiber well.  You usually need blue, IR
or something like that to get to over a meter of fiber length with analog
signals.  The glass fiber ones can go miles and really are worth the extra
money.  But they are a lot extra...

Cheers,

	Terry



At 11:03 PM 8/24/2002 -0600, you wrote:
>I like to measure KV and mA supplied by my filtered DC supply while it is
>powering my twin TC.  The supply is plus & minus 10KV, center grounded (4
>MOTs, twin doublers).  I now use analog meters directly wired into the HV
>and have the meters located away from the coil so I can read them without
>getting streamer zaps.
>
>I don't like the meters floating at high voltage - not safe.  I would like
>them isolated by optical fiber cables.  If I use a simple LED and
>phototransistor combination, or LED and photodiode and op amp, what
>linearity can I expect?  I need to measure 0 to 20 KV and 0 to 200 mA.
>
>If any of you have built fiber isolated V & A meters, please share details
>and results.
>
>Thanks,
>--Steve Young
>
>