Icom ID-800H, Руководство по обслуживанию, Страница: 19 / 59

4 - 9
4-5 OTHER CIRCUITS
4-5-1 SUB CPU RESET CIRCUIT (CONTROL UNIT)
IC2 is the reset voltage detecting circuit. The output voltage
from the +5 regulator circuit (IC5) is applied to the VDD
terminal (IC2, pin 2). IC2 outputs “H” (high) signal to the sub
CPU (IC6, pin 15) when the VDD terminal’s voltage is higher
than detecting voltage.
IC6 employs the 8-bit CPU.
4-5-2 LCD AND KEY BACKLIGHT CIRCUIT
(CONTROL UNIT)
The sub CPU (IC6) o8 regulator circuit (Q1, Q3,
D5) control signal from pin 2. The voltage from +8 regulator
circuit is applied to the key backlights (DS13–DS18, DS20,
DS23) and LCD backlights (DS21, DS22).
The backlight color is controlled by the sub CPU via the color
control circuit (Q6, Q7). The backlight has 3 colors (Amber,
Green and Yellow).
4-5-3 WATHER ALART (USA version only)
A portion of the demodulated audio signals from the AM/FM
switch (IC5, pin 1) are passed through the low-pass filter
(R46, R52, C52, C53), and then applied to the main CPU
(IC505, pin 42) via the “WXALT” signal to detect WX alert
signal.
4-4-3 MAIN UNIT VOLTAGE LINE
Line Description
HV
The voltage from the external power supply via
the W501.
VCC
The same voltage as the HV line which is con-
trolled by the VCC regulator circuit (Q501). The
circuit is controlled by the power switch control-
ler (Q502).
8V
Common 8 V converted from the VCC line at
the +8 V regulator circuit (IC504).
VT8
Transmit 8 V for VHF band controlled by the VT8
regulator circuit (Q19, Q22) using the "VTXC"
signal from the main CPU (IC505, pin 21).
UT8
Transmit 8 V for UHF band controlled by the
UT8 regulator circuit (Q20, Q23) using the
"UTXC" signal from the main CPU (IC505, pin
20).
5V
Common 5 V converted from the HV line at the
+5 regulator circuit (IC503).
5VS
Common 5 V converted from the 5 V line at the
+5S regulator circuit (IC503, D504). The circuit
is controlled by the power switch controller
(Q502).
V_VCO8
VCO 8 V for V-VCO controlled by "V_VCO" sig-
nal from the CPU (IC505, pin 81).
U_VCO8
VCO 8 V for U-VCO controlled by "U_VCO" sig-
nal from the CPU (IC505, pin 63).
R5
Receive 5 V controlled by the R5 regulator cir-
cuit (Q24) using the "R5CTRL" signal from the
CPU (IC505, pin 78).
AM5
Receive 5 V line for AM circuit controlled by the
AM5 regulator circuit (Q25) using the "AM" sig-
nal from the main CPU (IC505, pin 69).
VHF_R5
Receive 5 V line for VHF band circuit controlled
by the VHF_R5 regulator circuit (Q26) using the
"RXVHF" signal from the main CPU (IC505, pin
73).
UHF_R5
Receive 5 V line for UHF band circuit controlled
by the UHF_R5 regulator circuit (Q27) using the
"RXUHF" signal from the main CPU (IC505, pin
74).
400_R5
Receive 5 V line for 400 MHz band controlled
by the 400_R5 regulator circuit (Q28) using the
"RX400" signal from the main CPU (IC505, pin
67).
800_R5
Receive 5 V line for 800 MHz band circuit con-
trolled by the 800_R5 regulator circuit (Q29)
using the "RX800" signal from the main CPU
(IC505, pin 66).