2
1. Car Power Amplifier
R
(STEREO)
+
-
L. AMP.
-
+
-
+
R. AMP.
(INVERT.)
-
+
+
C131
220
16V
R154
4.7k
C221
0.1
R254
1k
-
-
+
+
-
L
HOT
HOT
MONO STEREO
150W@
0.04% THD
380W@
0.1% THD
INPUT
FIGURE 1-1 - FLEXIBLE INPUT CONFIGURATION
12A125 1487 11/11/02
+
+
-
BATT.
DC
INPUT
PL801
30 OHM
AMP.METAL
CASE
C804
0.1
R811 2.2k
C101
C102
C201
C202
MONO
4Ω
4
Ω
4
Ω
Chapter 1 - Car Power Amplifier
This power amplifier section is divided into the following parts:
• Hookup
• Circuit Block Concept / Overview
• Pulse Power Supply – Power ON / Audio Unmute
• Pulse Power Supply – Oscillator / Output
• Pulse Power Supply – Testing
• Audio Processing – Input Stages
• Audio Processing – Output Operation
• Audio Processing – Output Troubleshooting
• Protection Circuit – Oscillator Stop 1 (Thermal)
• Protection Circuit – Oscillator Stop 2 (Offset)
• Protection Circuit – Oscillator Stop 3 (Current)
Hookup
Single Speaker – Mono or Center
Mono - By changing the audio input, output and ground configuration, the stereo power amp can alternately be
used in a bridged monaural configuration for more power as shown in Figure 1-1. Only the left input jack is used
in monaural.