Differential voltage probes Safety Issues

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

Original poster: "Wall Richard Wayne by way of Terry Fritz <teslalist-at-qwest-dot-net>" <rwall-at-ix-dot-netcom-dot-com>


Terry,

I've given some thought lately to safety issues regarding overvoltage of
the front end of the differential voltage probe.  I disagree that a "fuse"
is going to do much to protect the differential probe and the scope (and
operator) attached to it.  Once an arc occurs and plasma forms there's no
way to control the destruction of probe and scope.  I believe a new design
is in order.

A fiber optic system should be placed between differential probe and scope.
Continue to design the front end of the probe as is, but without fuses.
The differential output of the probe should drive a fast fiber optic op
amp.  The fiber optic leads are to a second fiber optic receiver op amp and the
scope.  There are fast fiber optic cables and receiver op amps available.
An example is the SA 5212 at 150 mhz.

You should recognize the technology.  You pioneered fiber optic Tesla coil
instruments.  For a few dollars more you can design and build a much safer
instrument for both scope and users.  Much cheaper in the long run than
scope destruction or operator injury.

RWW