Pulsar TC-10B, User Manual

Page: 95 / 190

Carrier Stop
When jumper JU5 is in the NORM position,
carrier stop will initiate when jumper JU2
(pins A-16/C-16) is set at the appropriate
voltage level (15V, 48V, 125V, or 250V);
when JU5 is in the INVERT position, carrier
stop will initiate when voltage is removed.
Low-Level Test
When jumper JU4 is in the NORM position, a
Low-Level test will initiate when jumper JU3
(pins A-22/C-22) is set at the appropriate
voltage level (15V, 48V, 125V, or 250V);
when JU4 is in the INVERT position, a Low-
Level test will initiate when voltage is
removed.
When the appropriate jumper is in place on the
board, jumpers JU1, JU2, and JU3 provide logic
“1” or “0” inputs. (Proper polarity of these input
commands must be observed.)
You can manually initiate a Low-Level test by
pressing the (recessed) push button switch (S2) on
the front panel. You can manually initiate a High-
Level test by pressing the (recessed) push button
switch (S1).
You can initiate an optional High-Level
checkback key through pin C-8. You can initiate
an optional Low-Level checkback key through pin
C-28. A voice key can be initiated through pin
C-24.
Keying Module outputs are as follows:
High-Level (10W) Key Pin A-8
Any Transmitter Key Pin C-6
(1-W, 4.3W, or l0W)
Voice (4.3W) Key Pin A-6
Front panel LEDs are illuminated as follows:
D10 High-Level
D11 Low-Level
D12 Voice
You can make the STOP command inhibit the
High-Level (10W) output by using jumper JU7.
The STOP command also inhibits the Voice Key
output. The Voice Key is inhibited by the High-
Level and Low-Level Keys.
Zener diodes (D1, D2, D3) limit the input voltage
to the optical isolators (I7, I8, I9), while also
providing reverse voltage protection. Zener diodes
(D14, D13) regulate primary power (pins
A-2/A-4, pins A-30/A-32, pins C-30/C-32) down
to 15V, while also providing reverse voltage
protection.
Transistor (Q1), JU8, R40, D15, D16, D17, and
R41 are used for special applications with KDAR
and SKBU type keying circuits. These particular
relay applications have a single line input for
carrier start. The line has a tri-state condition, i.e.,
it is active high, active low, or open circuit. For
example, as shown in Figure 2-13 in the
Applications chapter, under normal operating
conditions, the input to TB4-1 is an open circuit
(while looking back into Z1). CSB, CSP, and SQ
are open, and zener diode (Z1) is much larger than
20Vdc. When the carrier test switch is depressed,
or the phase and ground carrier start contacts
open, the line going to TB4-1 goes active high. If
the phase and ground carrier stop contacts close,
the line going to TB4-1 is active low.
As shown in the schematic of the keying load
(Figure 10-3) and Q1 circuitry, when A-10 is high
(same as TB4-1), carrier start is initiated and
carrier stop is inhibited. This is caused by R40 and
D15 saturating Q1 and shorting out the stop
voltage applied to D7. C-16 is connected to the
battery so that D2 ALWAYS has 20V across it.
When TB4-1 (A-10) goes active low, Diode D17
shorts out the drive voltage to Q1, and internal
diode I8 conducts, causing a STOP function to be
generated. The following TRUTH table illustrates
the operation:
October 2003 Page 10–3
Chapter 10. Keying Module
10
NOTE
Carrier start will initiate a High-Level test.