Hi all,
Thank you for all great replies to my question!
I understand now it is enough with only a couple of ohms for the B- to
chassis resistor. However, contrary to this I came across a couple of
articles written by G3SEK in Radcom about HV PSU design (Jan-Mar
2009). Excellent articles that really explains a lot to me. But, in
his example he actually uses a 100 ohm from B- to chassis. The
resistor is also in parallel with 3 big diodes. He explains that they
serve a a return path to ground for surge currents and that the 100
ohm resistor is there to act as a backup for the diodes. But he does
not mention anything about how the metering is accomplished in this
case; with a 100 ohm you would have maybe 25-35 volts over the
resistor, so a meter would have to be shunted. And when shunted we
would bring down the resistance to a low value again which in its turn
would make it unnecessary with such a high value in the first place.
At least according to my logic!
Anybody likes to comment on that?
73's
Ulf SM0NOR
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|