Bosch Appliances 3.5 8Power Amplifiers, 8.1Introduction, 1: Block diagram of a power amplifier

Praesideo 3.5 Installation and User Instructions 4 Amplifiers

en 133

8Power Amplifiers

8.1Introduction

The PRS-1P500, PRS-2P250 and PRS-4P125 power amplifiers are the successors of the LBB4421/10, LBB4422/10 and LBB4424/10 power amplifiers. The main difference is that the efficiency of the new amplifiers is higher, so their power consumption is less for the same output power. This is especially noticeable in Idle mode and in Stand-by or Power save mode, saving valuable battery power in situations where this is allowed (not for EN54-16 compliant installations).

The main function of the Power Amplifiers is the amplification of audio signals for the loudspeakers. The amplifiers are high-efficiency class D amplifiers with

switched mode power supply. The amplifiers are protected against overload, overheat and short-circuits. See figure 8.1 for a block diagram of the power amplifier.

The power amplifiers have configurable audio processing functions, like parametric equalization, audio delay and the possibility for noise dependent automatic volume control (AVC).

Note

The number of inputs, spare amplifier

connections, loudspeaker lines and control outputs depends on the type of power amplifier.

		Display + Control
		D/A	Class D	Loudspeaker Out
Audio Inputs	A/D		(1..8)
		(1..8)		Spare Amplifier
		Network
		Processor
		+
Control Inputs		DSP
	I	O		Control Outputs (1..8)
POF		Network
		Redundancy
POF		Switching
				Mains
		Power Supply
				48 V Back-up

figure 8.1: Block diagram of a power amplifier

Bosch Security Systems 2011-02