ORIGINAL MESSAGE:
On Mon, 9 Nov 2009 10:57:46 -0500, "Carl" <km1h@jeremy.mv.com> wrote:
>I fail to see where you obtain a -3000V, perhaps its a terminology
>confusion.
REPLY:
In a conventional GG amp, both B+ and B- are floating with respect to ground,
except for the connection from B- to ground for the grid current meter.
If the B+ arcs to ground anywhere and there is no clamping diode, the B- in
instantly driven to the full negative HV with respect to ground. If your HV is
3000 VDC, the B- ;lead becomes -3000 VDC. The clamping diode from B- to ground
prevents this.
Incidentally, this is why one should never short the B+ to ground when trying to
be sure the HV caps are discharged before working on the amp. Short B+ directly
to B- only, not to the chassis.
73, Bill W6WRT
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