Icom IC-M802 3-6POWER SUPPLY CIRCUITS

3-5-3 GROUP AND CHANNEL DIALS CIRCUIT (DISPLAY AND SENSOR BOARDS)

•GROUP DIAL

The signals from the group dial (SENSOR board; S8801) is applied to the FRONT CPU (IC8201, pins 76, 77) via the “GPA” and “GPB” signals.

•CHANNEL DIAL

The signals from the channel dial (SENSOR board; S8802) is applied to the FRONT CPU (IC8021, pins 74, 75) via the “CHA” and “CHB” signals.

3-5-4 KEY’S BACK LIGHTS CIRCUIT (DISPLAY BOARD)

The key”s back lights compose DS8340–DS8350, and are controlled by the dimmer circuit (Q8340–Q8345). The dimmer circuit is controlled by the CPU via the “DIMMER” signal from the FRONT CPU.

3-5-5 RESET CIRCUIT (DISPLAY BOARD)

The reset IC (IC8202) resets the FRONT CPU (IC8201) when IC-M802 is power ON or OFF.

3-6 POWER SUPPLY CIRCUITS

3-6-1 PA UNIT VOLTAGE LINE

LINE	DESCRIPTION
HV13	The voltage from an external power supply.
HV	The same voltage as the	HV13	line	passed
	through the fuse (F6701).
S13V	The same voltage as the	HV13	line	passes
	through the switching relay (RL6701).
PA8V	8 V for transmitter circuits regulated by the +8
	regulator circuit (IC6601).
PAT8	8 V for transmitter circuits regulated by the T8
	regulator circuit (Q6601, Q6602).

3-6-2 DISPLAY BOARD (RC-25) VOLTAGE LINE

LINE	DESCRIPTION
HV13	The voltage from PA and MAIN units via the
	J8602.
10V	Common 10 V converted from the 13 V line and
	regulated by the +10 regulator circuit (IC8301).
5V	Common 5 V converted from the 5 V line and
	regulated by the +5 regulator circuit (IC8290).

3-6-3 PLL UNIT VOLTAGE LINE

LINEDESCRIPTION

HV13 The voltage from PA and MAIN units via the J5001.

H5V Common 5 V line from the MAIN unit via the J5071.

5V Common 5 V converted from the 13 V line and regulated by the +5 regulator circuit (IC5001).

8VL Common 8 V converted from the 13 V line and regulated by the +8 regulator circuit (IC5031).

3-6-4 MAIN UNIT VOLTAGE LINE

LINE	DESCRIPTION
S13V	The voltage from the PA unit via the J1901.
R13V	Receive 13 V converted from the S13V line and
	regulated by the R13 regulator circuit (IC1303).
8V	Common 8 V converted from the 13 V line and
	regulated by the +8 regulator circuit (IC1502).
	Common –5 V converted from the 13 V line and
–5V	regulated by the –5 V DC-DC converter (IC1551,
	D1551, D1552)
T8	Transmit 8 V converted from the S13V line and
	regulated by the T8 regulator circuit (Q1501).
R8	Receive 8 V converted from the S13V line and
	regulated by the R8 regulator circuit (Q1502).
5V	Common 5 V converted from the 13 V line and
	regulated by the +5 regulator circuit (IC1501).
H5V	Common 5 V converted from the 5 V line and
	regulated by the +5 regulator circuit (IC3101).

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