Programming instructions

TRIAC
 National Instruments Corporation 3-17 Multisim Component Reference Guide
When the triac is off, the resistance R
s
is set high to act as a current block. When the triac is
on, R
s
is low (1e-06).
The triac is switched on in either direction if:
Vd ≥ Vdrm
Rs = 1e - 06
or
Vd ≥ 0 and
Ig ≥ Igt at Vg ≥ Vgt
or of the triac
The triac is switched off and the resistance
R
s
is set high (current-blocking mode) if:
Id < Ih
.
In this case the switching occurs after turn-off time T
q
,
which is implemented by the
behavioral controller.
Vs = maximum forward breakover voltage, or switching voltage, in volts
I
d
= current through the diac, in amperes
R
s
= blocking resistance, in ohms
I
rev
= peak off-state reverse current
v
br
= maximum forward breakover voltage, in volts
i
d
= current through the triac, in amperes
Vd = voltage across the diac, in volts
vd = voltage across the triac, in volts
t
d
= turn-on time, in seconds
Other symbols used in these equations are defined in “Triac Parameters and Defaults”.
V
I
drm
drm






dV
dt
dV
dt
d
≥
ComponentRef.book Page 17 Thursday, December 7, 2006 10:12 AM