bidirectional trigger diode which
is designed specifically to trigger a
triacs or SCRs.
do not conduct (except for a
small leakage current) until the
voltage is reached.
that point the diac goes into avalanche
conduction and the voltage drop across the diac snaps
back. (about 5 volts).
creates a breakover current
sufficient to trigger a TRIAC or
diacs have symmetric switching voltages. Typical diacs have a
power dissipations ranging from only 1/2 to 1 watt.