Bosch Appliances 3.5 manual 5: Control outputs details, en

Praesideo 3.5 Installation and User Instructions 4 Amplifiers

en 139

8.3.5.3 50 V output

The 50 V output provided by the amplifier channel is actually a tap-off from the 50 V voltage for the loudspeaker line. The availability of the 50 V line does not depend on the selected loudspeaker voltage, since the tap-off is situated in front of the jumper (see figure 8.6).

	Spare In +
100 V	Lsp Out +
70 V		50 V
50 V	50 V
		100 V
	Spare In -
		50 V
	Lsp Out -
	0 V
figure 8.6: 50 V output

If the 50 V is connected to ground, a ‘balanced’ output for the loudspeaker voltage can be created. In that case, the maximum voltage between the loudspeaker line and ground is never more than 50 V (see figure 8.6). The actual voltage between the loudspeaker line and ground depends on the position of the jumper switch.

If the 50 V is connected to ground on purpose, the ground supervision of the amplifier output should be disabled using the configuration software (see section 43.3.4).

8.3.5.4 Control outputs

Each amplifier channel has one control output. The control output can be used to send signals to third party equipment to trigger actions. Each control output has three pins (see figure 8.4). The common (C) pin of the control output should always be connected. Whether the other pin that is connected is the normally closed (NC) or normally open (NO) depends on which action you want to take place when the control output is active (see table 8.5).

table 8.5: Control outputs details

Behavior	Abbreviation	Description
Normally	NC	By default, the NC
closed		contact is connected
		with common contact
		C. When the output is
		activated, the NC
		contact is opened.
Normally	NO	By default, the NO
open		contact is not
		connected with
		common contact C.
		When the output is
		activated, the NO
		contact is closed.

In the configuration, a purpose must be attached to the control outputs that indicates the action to be taken when it becomes active (see table 43.6). For example, the power amplifier control outputs can be configured as a Volume override output to create volume overrides.

8.3.5.5 Spare amplifiers

If a power amplifier has a defect, all loudspeaker lines are switched automatically to a spare amplifier (if connected and configured). See figure 8.7 for a connection diagram. Keep the following in mind:

•The main and spare power amplifiers must be of the same type. If the main power amplifier is a PRS-4P125, the spare power amplifier must also be a PRS-4P125

•The way the loudspeaker lines are connected to the spare amplifier must be exactly the same as the way they are connected to the main amplifier. For example, if the loudspeaker lines use the fixed 50 V output of the main amplifier, they also must be connected to the fixed 50 V output of the spare amplifier.

Bosch Security Systems 2011-02