[Amps] PSU design question

[Ulf Tjerneld]

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