Re: Floating Scopes

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Crow Leader by way of Terry Fritz 
<twftesla-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

 > Is there any evidence that the currents from top of a secondary to the top
 > terminal of whatever capacitance a user has will be any different than the
 > ground current from bottom of the secondary to earth? I'd normally say of
 > course they have to match, but who knows, maybe there is interesting
 > capacitive coupling between the secondary coil itself and the top terminal
 > resulting in currents that never have to even flow through the coil's
 > ground.

The curents are different. If there is no top load at all, the current
between the end of the coil and the terminal is obviously zero. If
a large terminal is used, the currents tend to be equal. The simple
lumped model of the secondary coil, where there is a "self-capacitance"
in parallel with the coil explains this. The base current is split
between the current that charges the "self-capacitance", that can't
be directly measured, because it's a distributed current charging
a distributed capacitance along the surface of the coil, and in
irregular way to complicate the things, and the current that goes to
the terminal, that can be easily measured.

Antonio Carlos M. de Queiroz