Bosch 3.5 User Manual

Page of 498
Bosch Security Systems | 2011-02
Praesideo 3.5 | Installation and User Instructions | 4 | Amplifiers
en | 166
10
Basic Amplifiers
10.1 Introduction
The basic amplifier is available in these versions:
PRS-1B500: 1 channel, 500 W.
PRS-2B250: 2 channels, 2 x 250 W.
PRS-4B125: 4 channels, 4 x 125 W.
PRS-8B060: 8 channels, 8 x 60 W.
The basic amplifier is a high efficiency class-D power 
amplifier for public address and emergency sound 
systems and is designed as an extension to the Praesideo 
system but can also work as a stand alone amplifier. If 
not used as a stand alone amplifier, the basic amplifier is 
used in conjunction with the multi channel interface 
which provides the audio signals and control.
The basic amplifier is completely supervised and fault 
events are reported via the multi channel interface to 
the Praesideo network controller.
Loudspeaker lines and loudspeakers connected to a 
basic amplifier channel can be supervised by using the 
LBB4441 and LBB4443 supervision boards. The multi 
channel interface acts as a supervision controller, so no 
LBB4440 is required.
In contrast to the power amplifiers, the basic amplifiers 
do no offer built-in audio processing functions as 
equalization, delay and automatic volume control.
figure 10.1: Block diagram of a basic power amplifier
LED Indicators
Loudspeaker Out A
Audio input
Power Supply
Multi Channel 
Interface
Audio input
Multi Channel 
Interface
Priority Switching
+ Supervision (2)
Priority Switching
+ Supervision (1)
Loudspeaker Out B
Spare In
Loudspeaker Out A
Loudspeaker Out B
Spare In
Mains
48 V Back-up
Class D
(2)
Class D
(1)