EFJohnson 001-9800-001 User Manual

3-3

February 2001

Part No. 001-9800-001

+

Chassis

Ground

Vehicle
Battery

15A

Fuse

Power

Cable

Power Amplifier

Board

Transceiver

Power

Connector

CR600

Transient

Suppressor

Unsw Bat

Unsw Bat

Sw Bat

Unsw Bat

J600

J201

1

2

11

J501

J302

F500

4A

Q510

Switch

Front Panel

On-Off Sw

U501

U105

8V

Regulator

5V

Regulator

8V

5.5V

Regulator

8V Tx

Switch

U502

Q504

5.5V

8V Tx

From Shift
Reg U801

From Latch

U112 A/L Bd

Sw Bat

2

5

15

Sw Bat

8V

Vcc

12

J100

J3

Sw Bat

Sw Bat

Sw Bat

J2

J1

2

5

J1

Microphone

Jack

Display Board

Interface

Board

Audio/Logic

Board

RF Board

R533

F100

2A

R2

High Tier

On-Off Sw

On-Off

Latch

(A/L Bd)

Low Tier

4

10

11

High

Tier Only

Front Panel

On-Off Sw

20

18

J3

J302

J100

J201

Q107

Q108

Power Switch

Sense

Ignition On

Sense

To uC,
Pin 60

To uC,
Pin 62

Q110

Power Hold

From Shift Reg

U111, Q7

Unsw Bat

Unsw Bat

R170

From Ignition

Switch

This Resistor Installed If

Ignition Sense Not Connected

Q510

Supply

Switching

Circuit

Interface Board

(High Tier Only)

Audio/Logic Board

RF Board

Q109

Sw Bat

Note: Arrows Indicate Signal Flow.

U113A-D

Power On-Off Latch

Low Tier Only

5

1

filtering of the 13.6-volt supply. The emitter of Q513 
is biased at about 4.5 volts by R538 and R542 (with a 
battery voltage of 13.6 volts). CR504 mirrors the base-
emitter voltage of Q513, and the voltage across R541 
is the same as the voltage across R542 when the 
voltage applied to R536 is approximately 12.8 volts. 

Noise pulses less than 1.6 volt P-P then do not 

appear on the output of Q510 because of the emitter 

voltage filtering provided by C565. This reduces the 
amount of noise applied to circuits powered by the 
switched 13.6-volt supply such as audio power ampli-
fier U306. Additional filtering of the switched and 
unswitched battery supplies is provided by C548-
C553. Resistor R534 turns Q514 off when power is 
turned off.