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Hexfred and zener

Started by LJ King, July 15, 2007, 12:01:43 PM

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LJ King


Sounds like two good names for a RPG.

Anyways, is it possible to wire up a hexfred so it behaves like a zener - like for voltage regulation?

tonyharker

Why would you want to do that?  You would have to wire it in reverse and the breakover voltage would be in the hundreds with allowed inverse current very small in microamps. Otherwise you would destroy the diode!

LJ King


No, it's not a case of me wanting to do it.

I got a note from a friend of mine. His amp is mainly tube but there are some op amps for the reverb. There is a separate supply for the op amps and it is supposed to have zeners across both sides of the dual polarity supply.

But instead, it has some kludge type wiring (i.e. "handwired" above the circuit board), no zeners, but hexfreds where the zeners are supposed to be.

I'm not sure if hexfreds could serve the same purpose, but then again I don't have a clue what the purpose could be. It's just some weird mod that doesn't match the schematic.

teemuk

If I have understood correctly a HEXFRED is just an ordinary diode with fast switching characteristics so the configuration doesn't sound right - but maybe you have just misinterpreted the purpose of those diodes. Is the rail voltage for opamps still about +-15VDC or has it dropped to +-600mV?