tca280b Hendon Semiconductors, tca280b Datasheet - Page 21

• Manufacturer Part Number: tca280b
• Description: General Purpose Triggering Circuit
• Manufacturer: Hendon Semiconductors

Integrated Electronic Solutions, Hendon, South Australia
10.7
The output amplifier (Fig 15)
produces a trigger pulse at pin 10 as
soon as TR22 is driven via D19. The
voltage regulator diode D19 prevents
spurious triggering caused by
uncontrolled pulses during the rise
time of the operating voltage when
2002 Nov 08
General purpose triggering circuit
Output amplifier
triac gate
feedback
to
−
+
Fig.15 Connection of the output amplifier
the trigger stage is switched on.
Transistor TR26 represents a
low-ohmic parallel connection for the
base current supplied to pin 9.
Consequently, the trigger pulses can
be produced only when TR26 is off.
Feedback loops from the output
amplifier, to the zero-crossing
11
R G
20
R15
TR22
kΩ
10
TR23
TR24
D19
TR25
TR26
D20
10 QA
9 IA
8 INHA
Fig-15-circuit
detector and the inhibiting stage via
R6 and R8 (see Figure 10),
respectively, increase the rise time of
the pulses, and provide a holding
circuit for the pulse generating
network for the required pulse
duration.
TCA280B
Data Sheet