Homer J Simpson schrieb:

[two zeners as replacement for a diac]

IIRC, a diac is like a triac with no gate - when it fires the dropped
voltage is a couple of volts only. This is unlike a zener.

You're right: but would there be a difference in function between a
triac triggered (at 30 V) by a diac and a triac triggered (at 30 V) by
two back-to-back zeners? Wouldn't both of them conduct current until its
next zero crossing?

Wondering

Reinhard