Icom IC-PW1, Service Manual Addendum

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3 - 8
3-6-4 REGULATOR CIRCUIT
(SUBREG UNIT)
Either 13.6 V or 18 V DC are supplied from their corre-
sponding regulator circuits. These are regulated from the
380 V DC (When input voltage is 100 V AC, outputs 300 V
DC).
(1) 13.6 V AND 18 V REGULATORS
The AC voltage from the REGRELAY unit passes through
the AC filter circuit (L4, C30, C31), and is rectified by D1.
The signal passes through R1 to prevent an entry of current
until 300 V AC (When input is 100 V AC, preventing an entry
of current until 140 V AC) The signal is smoothed and con-
verted to the DC voltage by C1.
The DC voltage passes through R4 and R16, and is then
applied to the base terminal of Q1. The signal passes
through T1 (pins 3, 1), then generates the DC voltage at T1
(pins 6, 8). Because the RCC circuit (D3, D4, D10) are
reverse connection, the current does not pass through T1
(pins 9, 10 and 13, 15).
When the base current of Q1 can not hold saturation volt-
age, collector-emitter voltage of Q1 is increase. Therefore,
the voltage of T1 (pins 1, 3 and 6, 8) and the base current of
Q1 are decrease, and then Q1 switches OFF. The same cur-
rent of T1 (pins 1, 3 and 6, 8) passes through the pins 9, 10
and 13, 15 of T1, and then D3, D4, D10 are forward direc-
tion. Thus, the voltages output from T1.
When finishes outputting voltage from T1, the RCC circuit
(D3, D4, D10) switches OFF. According to the residual volt-
age of T1, generated voltage at T1 (pins 6, 8). Q1 is
switched ON by the voltage, and then run the switching cir-
cuit repeat the same thing.
The signal from T1 (pins 13, 15) passes through the rectifi-
cation circuit (D4), and is then applied to the IC-PW1, etc as
“12 V” line.
Part of signals from D4 is applied to the RCC control circuit
(IC3). When voltage of D4 is high, the transistor which is
included in IC2 is switched ON by the RCC control circuit
(IC3). The signal from IC2 is applied to Q2, and is then
applied to Q1 to control the base current. Thus, the RCC cir-
cuit can obtain stabilized voltage.
The signal from T1 (pins 9, 10) passes through the rectifica-
tion circuit (D3 and D10), and is then applied to the 18 V reg-
ulator circuit (IC5). The output voltage is applied to the ACT-
FIL unit as “A18+” line after being passed through the 18 V
short start switch (Q6).
(2) 100/200 V AC VOLTAGE DETECTION CIRCUIT
The AC voltage from the REGRELAY unit passes through
the AF filter circuit (L4, C30, C31), and is then rectified and
smoothed by D8 and C26 to convert the AC voltage to the
DC voltage. The DC voltage passes through the voltage
divider (R18–R21), and is applied to the AC 100/200 V
select circuit (Q4, Q5, D9).
When the divided voltage is above the zener voltage of D9,
the voltage passes through D9, and Q5 is switched ON to
control the 200 V AC detection circuit.
When the divided voltage is below the zener voltage of D9,
Q5 is switched OFF to control the 100 V AC detection circuit.
The signal is applied to IC4 and IC7.
The signal from IC4 is applied to Q7 on the ACTFIL unit via
the “SELV” signal to control the active filter control circuit
(ACTFIL unit; IC1).
The signal from IC7 is applied to the IC-PW1 via the “SEL”
signal. Part of the “SEL” signals is applied to the Q15 and
Q16 on the CONV-CTRL unit to control the inverter control
unit (CONV-CTRL unit; IC1).
"HVSA" signal
from CONNECT unit
"12V" signal
"12V" signal
"SL" signal from the
REGRELAY unit
AC filter circuit RCC circuit
1, 3
10
T1
IC2
IC7
IC4
Q5
IC6
15
6, 8
RCC control circuit
AC 100/200 V
select circuit
18V regurator
"12V" signal
"SEL" signal to the
CONV-CTRL unit, etc
"SELV" signal to the
ACTFIL unit
"12V" signal
"18V" signal
• REGURATOR CIRCUIT