Power Supply Circuits; Port Allocations - Icom IC-PW1 Service Manual Addendum

3-3-4 TEMPERATURE DETECTOR CIRCUIT
(SPLITR AND MAIN UNITS)
The temperature detector circuit detects the temperature of
the heatsink for final FETs and controls amplifying operation.
A thermistor (SPLITR unit; R16) detects temperature of the
heatsink for final FETs, and the detected temperature signal
(DC voltage) is applied to the main CPU (MAIN unit; IC26,
pin 12), to control the cooling fans and amplifying operation.
Common 5 V is applied to the thermistor for reference.
3-3-5 DRIVING FREQUENCY DETECTOR CIRCUIT
(SPLITR AND MAIN UNITS)
A portion of the RF signal from RL1 (SPLITR unit) is divided
at C18 and C19, then applied to the driving frequency detec-
tor circuit in the MAIN unit as the "F" signal.
The "F" signal from the SPLITR unit is amplified at the lim-
iter amplifier (MAIN unit; IC30) after being amplified at Q34
and Q35. The amplified signal is divided at the divider (MAIN
unit; IC20) for conversion to pulse-type signals. The signals
are applied to the main CPU (MAIN unit; IC26, pin 76). The
CPU counts the number of pulses as the driving frequency,
then controls the protector for frequency band selection.
The driving frequency detector circuit detects the input
power level at the same time to prevent malfunction at low
power level inputs.

3-4 POWER SUPPLY CIRCUITS

• VOLTAGE LINE
LINE
+12 V line from the regulator circuit. The output
voltage is applied to the meter lamp (FRONT
H12
unit; DS1, DS2).
12 V controlled from a H12 line by the relay con-
12 V
trol circuit (IC8, IC9).
5 V DC converted from a 12 V line at IC5 on the
MAIN unit. The voltage is used for the phase
5 V
detector on the DET unit.
5 V DC converted from a S12 line (+12 V) at IC6
on the FRONT unit. The voltage is used for the
+5 V
output expander IC on the FRONT unit.
–5 V DC converted from a –13 V line at IC5 on
–5 V
the DET board.
–13 V DC converted from a H12 (+12 V) line at
–13 V
IC8 on the MAIN unit.
Transmit 13 V DC converted from a H12 (+12 V)
T13
line at Q3 on the MAIN unit.
Transmit 8 V DC converted from a T13 line at
IC1 on the SPLITR unit. The output voltage is
T8V
used for PA1, PA2, PA3 and PA4 on the PA unit.
45 V line from the regulator circuit. The voltage is
HV
used for PA1, PA2, PA3 and PA4 on the PA unit.
DESCRIPTION

3-5 PORT ALLOCATIONS

3-5-1 EXPANDER IC (SWITCH BOARD; IC1)
Pin Port
number name
4 I1L
5 I2L
11 A4L
12 A3L
13 A2L
14 A1L
3-5-2 EXPANDER IC (SWITCH BOARD; IC2)
Pin Port
number name
4 VML
5 SML
6 AML
12 TML
13 IML
14 PML
3 - 4
Description
Outputs INPUT "1" LED control signal.
High: While INPUT "1" LED is ON.
Outputs INPUT "2" LED control signal.
High: While INPUT "2" LED is ON.
Outputs ANT "4" LED control signal.
High: While ANT "4" LED is ON.
Outputs ANT "3" LED control signal.
High: While ANT "3" LED is ON.
Outputs ANT "2" LED control signal.
High: While ANT "2" LED is ON.
Outputs ANT "1" LED control signal
High: While ANT "1" LED is ON.
Description
Outputs "V " LED control signal.
D
High: While "V " LED is ON.
D
Outputs "SWR" LED control signal.
High: While "SWR" LED is ON.
Outputs "ALC" LED control signal.
High: While "ALC" LED is ON.
Outputs "TEMP" LED control signal.
High: While "TEMP" LED is ON.
Outputs "I " LED control signal.
D
High: While "I " LED is ON.
D
Outputs "P " LED control signal.
O
High: While "P " LED is ON.
O