My guess is that a (shunt) 15v 10W zener isn't going to last long
with 20A available... best (but unlikely) case, long enough to trip
the (latching?) over-current
protection before vaporizing zener "open".
Allen--W7GIF
Yeah, that's kind of what I thought too, which is why I picked a 10W
zener. All I want is for it to blow the fuse and protect the radio...
don't really care if it fries itself. Although those Bel Power modules
look like they might work better. Thanks for the pointer.
I have used a 15v 10 watt zener diode and a 20 amp fusefor years.?
There is no current limiting resistor for the diode.? When the
voltage exceeds 15 volts,
the diodeconducts and the diode shorts blowing the fuse and the
equipment is protected.
Clayton N4EV
Yup, the idea with the zener being... You hook it up power to ground,
after the fuse, no limiting resistors or anything. if you reverse
polarity on the power, the zener conducts forward and blows the fuse.
If you overvoltage, it exceeds the reverse (zener) breakdown, conducts
reverse and blows the fuse. I used to do that years ago with homebrew
QRP stuff, but of course 1W zeners worked fine there.
-Tom N1OOQ
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