Specifications
c. The high input at the LR PAL U6-3 (High) will generate
a high Turn-On Request at U6-21 (TOR) as long as U6-13
(ENTOR)is high.
1. The ENTOR (Enable Turn-On Request) comes from
the FLT1 PAL U3-21. It must be high for the LR PAL
to generate a TOR.
2. The VSWR Test output at U6-18 will go high for 8mS,
this turns on Q1 and J7-9 VSWR Self Test Request
goes low. This low signal is sent to the Output Monitor
for testing the VSWR detectors.
d. Refer to Figure M-10, Step-Start Timing Diagram for the
following discussion.
e. The TOR from U6-21 is applied to the PWR PAL U7-11
and the PTIM PAL U8-10.
1. The high TOR input to U8-10 generates a high output
pulse at U8-20 1.5 seconds later. This output is sent to
U7-13 and is the signal that tells the PWR PAL to go
to the Ready State.
f. 32 ms later, on the second Timepulse, the output of U7-20
(KLV) will go high.
1. This signal turns on the transistor inside U43-8 and
J14-19 goes low. The solid state relay K5 closes and
single phase AC is applied to the low voltage power
supply(s) and they begin to charge up.
2. ThehighsignalisalsosentbacktoU8-6totellthe
PTIM PAL that K5 has closed.
3. When the +8 VDC supply is charged up, the output of
the Supply Voltage Sensing comparator U36-1
(KLVX) will go high and this signal is sent back to
U7-3.
g. On the third Time pulse, 32ms later, the output of U7-16
(MODENC) will go high.
1. This signal is connected to J14-20 and a TX ON
ENABLE-H is sent to the Transmitter Interface. The
TX ON ENABLE will:
a) Turn on the B+ and B- regulators, activate the fault
sensing, and supply the voltage for the fuse fault
detector on all of the Modulation Encoders.
b) Turn on the Predriver and applicable Drivers, delay
the Auto Driver Control for 1.5 Seconds, and delay
the Low Drive Fault sensing on the Driver Encoder.
c) Activatethe Air FlowMonitor A3inOutput Cabinet
via the control on the Output Monitor.
h. 32 ms later, on the fourth Time pulse, the output on U7-19
(Enable 1) will go high.
1. This signal is used by the Controller to activate some
fault inputs connected to FGATE1 and FGATE2 in
addition to clocking the Latch PAL U-12.
2. ThehighsignalisalsosentbacktoU8-7totellthe
PTIM PAL that Enable 1 is activated.
i. Also on the fourth Time Pulse, the output of U7-22 (K1)
will go high.
1. This signal will turn on the transistor U43-7 and J14-18
goes low. The step start solid state relay K3 closes and
single phase AC is applied to the Step Start contactor
K1. When K1 closes, 3 Phase AC mains are applied to
the RF AMP Power Supplies through the step start
resistors R1, R2 and R3. The supplies begin to charge
up through these current limiting resistors.
a) This signal remains high for 1.7 Seconds.
b) The high signal is also sent back to U8-4 to tell the
PTIM PAL that K1 is activated.
c) An auxiliary contact on K1 sends a high signal from
the +22VDC supply to J6-37 Step Start Status-H.
This signal is latched by U22-9 and K1X.X is sent
to U7-4.
j. On the sixth Time pulse, the output on U7-18 (Enable 2)
will go high.
1. This signal is used by the Controller to activate some
fault inputs connected to FGATE1, FGATE2, FLT1,
and the FLDBK PALs in addition to clocking the Latch
PAL U -1 1.
2. The high signal is also sent back to U8-8 to tell the
PTIM PAL that Enable 2 is activated.
k. Also on the sixth Time pulse, the output of U7-23 (K2)
will go high.
1. This signal will turn on the transistor U43-1 and J14-17
goes low. The run solid state relay K4 closes and single
phase AC is applied to the Run contactor K2. When K2
closes, 3 Phase AC is applied directly to the RF AMP
Power Supplies.
2. The high signal is also sent back to U8-4 to tell the
PTIM PAL that K1 is activated.
3. An auxiliary contact on K2 sends a high signal from
the +22VDC supply to J6-39 Run Status-H. This signal
is latched by U22-12 and K2X.X is sent to U7-5.
l. 128 ms later on the seventh time pulse, a 128 ms delay
timer is started.
m. 128 ms later on the eighth time pulse a 64 ms delay timer
is started.
n. 64 ms later the Time pulse, the output on U7-17 (Enable
3), will go high.
1. This signal is used by the Controller to activate some
fault inputs connected to FGATE1 and FLT1 in addi-
tiontoclockingtheLatchPALU-13.
2. Up until the point that Enable 3 goes high, FGATE1
has been generating an RF Mute low on U9-20 to hold
the Big Step and Binary RF Amplifiers off during the
turn-on sequence. When U9-9 goes high, U9-22 goes
high and the RF Mute is removed. The transmitter
power output goes up to the one quarter of the selected
power level and then steps to full power via the Power
Ramp circuit on the Analog Input board.
o. Two seconds later and repeated every two seconds after-
wards an Unfault pulse is generated for the FLT1 PAL.
This completes the Turn On Sequence.
M-12 888-2339-002
WARNING: Disconnect primary power prior to servicing.