>
>A different aspect to consider - what happens when there is anode-screen
>flashover. I inherited a PSU (with 10x33V/5W zener screen supply) from a
>friend. A dud tube caused a flashover and lots of damage.
? My guess is that the zeners shorted. In such a case, shorted (0
volts) zeners cause no damage. (10) 5w zeners only cost around 11
dollars.
>After some
>investigation, I came to the conclusion that 375V VDR clamps on the screen
>didn't protect anything, as their clamping voltage at 10s Amps is around
>600V+.
? The 10 x 33v zeners would have shorted at far less than 600v.
>The arc current went through the screen meter and shunt ...
? No glitch diodes for the meters is hardly good engineering practice.
.
cheers, Steve
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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