the fabled 'horoclamp'

[zumdar]

hello ee heads!

while trying to find the perfect overvoltage clamping circuit for my project i was reading the art of electronics (as you do)... and in section 9.13.1 they mention a wonderful solution to all my problems, a low voltage clamp-crowbar. Alas! exactly what i need. it clamps.. and it throws in the crowbar if things get really bad?? yesss!  but it was a tease.. it is too advanced for this 1000+ page tome and is relegated to AoE x chapters...

but then doing a quick search i come across this beauty: http://seti.harvard.edu/unusual_stuff/misc/crowbar.htm
and it even has a big honking relay just like the sucker i am trying to protect my circuit from.

does anyone have the schematic for this magical clamper?!?

thank you!!