Bosch PLN-1LA10 User Manual

Plena Loop Amplifier

Installation and User Instructions

en PLN-1LA10

Plena Loop Amplifier | Installation and User Instructions | Important safeguards	en | 3

Important safeguards

Before you install or operate the Plena Loop Amplifier, you must read the Important Safety Instructions. The Important Safety Instructions are supplied together with the Plena Loop Amplifier.

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Plena Loop Amplifier | Installation and User Instructions | Acknowledgements	en | 4

Acknowledgements

Bosch Security Systems thanks the NVVS (Dutch Association of Hard of Hearing People) for the valuable information that was provided during the development of the Plena Loop Amplifier and the creation of the Installation and User Instructions.

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Plena Loop Amplifier | Installation and User Instructions | About this manual	en | 5

About this manual

Function

The Installation and User Instructions gives the installers and operators the necessary data to install, configure and operate the Plena Loop Amplifier.

Digital version

The Installation and User Instructions is available as a digital file (Portable Document File, PDF).

When the PDF refers you to a location that contains more data, you can click the text to go there. The text contains hyperlinks.

Precautions and notes

The Installation and User Instructions uses precautions and notes. The precaution gives the effect if you do not obey the instructions. These are the types:

•Note

A note gives more data.

•Caution

If you do not obey the caution, you can cause damage to the equipment.

•Warning

If you do not obey the warning, you can cause personal injury or death.

Signs

The Installation and User Instructions shows each precaution with a sign. The sign shows the effect if you do not obey the instruction.

Precaution

General sign for cautions and warnings.

Precaution

Risk of electric shock.

The sign that is shown along with a note gives more data about the note itself.

Note

General sign for notes.

Note

Refer to another information source.

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Plena Loop Amplifier | Installation and User Instructions | About this manual	en | 6

Conversion tables

Length, mass and temperature are in SI units. Refer to the data below to change SI units to imperial units.

table 1: Conversion of units of length

1 in =	25.4 mm	1 mm =	0.03937 in
1 in =	2.54 cm	1 cm =	0.3937 in
1 ft =	0.3048 m	1 m =	3.281 ft
1 mi =	1.609 km	1 km =	0.622 mi
table 2: Conversion of units of mass
1 lb =	0.4536 kg	1 kg =	2.2046 lb
table 3: Conversion of units of pressure
1 psi =	68.95 hPa	1 hPa =	0.0145 psi

Note

1 hPa = 1 mbar.

table 4: Conversion of units of temperature

°F =	9	°C + 32
	---
	5
°C =	5	(°F – 32)
	9
	---

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Plena Loop Amplifier | Installation and User Instructions | Table of contents	en | 7

Table of contents

	Important safeguards ...................................................................................................................................................			3
	Acknowledgements.......................................................................................................................................................			4
	About this manual .........................................................................................................................................................			5
	Table of contents ...........................................................................................................................................................			7
1.	System overview ...........................................................................................................................................................			9
1.1		Loop amplifier ...........................................................................................................................................................................		9
1.2		Induction loop systems ..........................................................................................................................................................		9
	1.2.1		Introduction .........................................................................................................................................................................	9
	1.2.2		Principle ...............................................................................................................................................................................	9
	1.2.3		Benefits .............................................................................................................................................................................	10
1.3		Plena .......................................................................................................................................................................................		10
1.4		Block diagram .......................................................................................................................................................................		10
1.5		Supervision ............................................................................................................................................................................		10
1.6		Quadrature system ..............................................................................................................................................................		10
1.7		Controls, connectors and indicators ...............................................................................................................................		12
	1.7.1		Front view .........................................................................................................................................................................	12
	1.7.2		Rear view ..........................................................................................................................................................................	12
2.	Design and planning .................................................................................................................................................			13
2.1		Introduction ............................................................................................................................................................................		13
2.2		System types .........................................................................................................................................................................		13
	2.2.1		Simple system .................................................................................................................................................................	13
	2.2.2		Quadrature systems .......................................................................................................................................................	13
	2.2.3		Expanded quadrature systems ....................................................................................................................................	15
	2.2.4		Low-spill system ..............................................................................................................................................................	15
2.3		Induction loops .....................................................................................................................................................................		16
	2.3.1		Introduction ......................................................................................................................................................................	16
	2.3.2		Position .............................................................................................................................................................................	16
	2.3.3		Wire diameter ..................................................................................................................................................................	16
	2.3.4		Magnetic field strength ..................................................................................................................................................	16
	2.3.5		Connection .......................................................................................................................................................................	16
	2.3.6		Configuration ...................................................................................................................................................................	16
2.4		Potential problems ...............................................................................................................................................................		18
	2.4.1		Metal loss .........................................................................................................................................................................	18
	2.4.2		Overspill ............................................................................................................................................................................	18
	2.4.3		Earth loops .......................................................................................................................................................................	18
3.	Installation ...................................................................................................................................................................			19
4.	External connections ................................................................................................................................................			21
4.1		Induction loops .....................................................................................................................................................................		21
4.2		Audio inputs ..........................................................................................................................................................................		21
4.3		Priority input ...........................................................................................................................................................................		22
4.4		Fault output ............................................................................................................................................................................		23
4.5		Line output .............................................................................................................................................................................		23
4.6		Power supply .........................................................................................................................................................................		23
4.7		Slave to Master .....................................................................................................................................................................		25
4.8		Slave to slave ........................................................................................................................................................................		25
5.	Configuration ..............................................................................................................................................................			27

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5.1	Master and slaves ................................................................................................................................................................		27
5.2	Electric current ......................................................................................................................................................................		27
5.2.1		Master induction loops ..................................................................................................................................................	27
5.2.2		Slave induction loops ....................................................................................................................................................	28
5.2.3		Bracket ..............................................................................................................................................................................	28
5.3	Metal loss compensation ....................................................................................................................................................		28
5.4	Supervision ............................................................................................................................................................................		29
5.5	Fault contact ..........................................................................................................................................................................		29
5.6	Priority input ...........................................................................................................................................................................		29
5.7	AGC/Limiter ..........................................................................................................................................................................		29
5.7.1		Introduction ......................................................................................................................................................................	29
5.7.2 Switch on and off ...........................................................................................................................................................			29
5.7.3		Range ................................................................................................................................................................................	30
5.8	Frequency range ...................................................................................................................................................................		30
5.9	Audio inputs ..........................................................................................................................................................................		30
5.9.1		Sensitivity .........................................................................................................................................................................	30
5.9.2		Phantom power ...............................................................................................................................................................	30
5.9.3		Voice activation ...............................................................................................................................................................	31
6. Operation .....................................................................................................................................................................			33
6.1	Switch on ...............................................................................................................................................................................		33
6.2	Switch off ...............................................................................................................................................................................		33
6.3	Change volume .....................................................................................................................................................................		33
6.4	Change tone ..........................................................................................................................................................................		34
6.5	Condition LEDs ....................................................................................................................................................................		34

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Plena Loop Amplifier | Installation and User Instructions | System overview	en | 9

1 System overview 1.2 Induction loop systems

1.1Loop amplifier

The PLN-1LA10 Plena Loop Amplifier has been designed as a very high-quality amplifier for medium to large size induction loop systems. Ease of installation and use have been major factors in the design, combined with optimized performance.

1.2.1Introduction

An induction loop system consists of a looped wire that is installed along the walls of a room and a loop amplifier.

1.2.2Principle

The loop amplifier changes incoming audio signals in an alternating electric current that is sent through the induction loop. The strength and frequency of the electric current varies with the tone and the amplitude of the incoming audio signal and generates an alternating magnetic field inside the induction loop. People with assistive listening devices who are located inside the induction loop, can put their assistive listening devices in the T or MT mode to listen to the audio signals.

figure 1.1: Plena Loop Amplifier

table 1.1: Performance

Frequency response:

60 Hz to 10 kHz (+1/-3 dB, @ -10 dB @ rated output

Distortion:

< 1% @ rated output, 1 kHz

Bass control:

-8/+8 dB @ 100 Hz

Treble control:

-8/+8 dB @ 10 kHz

table 1.2: Certifications and approvals

EMC emission: acc. to EN55103-1

EMC immunity: acc. to EN55103-2

Safety:

acc. to EN60065

Induction loop systems:

acc. to EN60118-4 acc. to IEC118-4

In the T or MT mode, a little coil is activated (T stands for ‘tele-coil’). The coil receives the alternating magnetic field and changes it into an alternating voltage, which the assistive listening devices change into an audio signal. This audio signal is not entirely the same as the incoming audio signal of the loop amplifier, because the assistive listening devices also compensate for individual hearing disabilities (for example, signal strength and frequency range).

		T/MT	4
1	2	3	5

figure 1.2: Assistive listening device

table 1.3: Assistive listening device

No. Description

1Tele-coil

2 Microphone

3Gain control

4 Amplifier

5Earphone

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Plena Loop Amplifier | Installation and User Instructions | System overview	en | 10

1.2.3Benefits

Ambient noise prevents hard-of-hearing people from listening to a specific sound in a room. The ambient noise can result from other people in the room, equipment, but also from the acoustics. Depending on the acoustics of the room, hard-of-hearing people already find the reflected noise a strain when the distance between them and the speaker is more than 2 m. The induction loop, to which the hard-of-hearing people can listen with their assistive listening devices, virtually reduces the distance to the speaker. Their distance to the speaker seems equal to the distance between the speaker and the microphone.

1.3Plena

The Plena Loop Amplifier is part of the Plena product range. Plena provides public address solutions for places where people gather to work, worship, trade or simply enjoy themselves. It is a family of system elements that are combined to create public address systems tailored for virtually any application. The range includes mixer, pre, system and power amplifiers, a source unit, digital message manager, feedback suppressor, conventional and PC call stations, an ‘All-in-One’ system and a voice alarm system. Each element is designed to complement all others thanks to matched acoustical, electrical and mechanical specifications.

1.4Block diagram

Refer to figure 1.4 for a block diagram of the Plena Loop Amplifier.

1.5Supervision

All vital functions of the loop amplifier are supervised. The loop amplifier checks its internal power amplifier, the integrity of the connected induction loop and the priority input with a pilot tone. When a supervised function fails, a LED on the front panel of the loop amplifier is lit and the fault contact is de-energized.

1.6Quadrature system

One of the key features of the Plena Loop Amplifier is that it can be used in quadrature systems. In a quadrature system, an even number of Plena Loop Amplifiers work together to create a magnetic field that has the same strength throughout the whole covered area and drops rapidly to zero beyond the borders of the covered area. This is achieved by introducing a phase difference of 90° in the electric current that flows through two adjacent induction loops.

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Plena Loop Amplifier | Installation and User Instructions | System overview	en | 11

1									2		3
0 dB								1	5		10
-6 dB									Current		Fault
-20 dB
Power	1	2					Master
								Loop		AGC	Limiter
	0	0	_	+	_	+		Integrity
							0
11		10			9		8	7		6	5	4
		12		13		14	15	16				17	18

			Line Out
		Slave Out	Fault
Master In	VU LED
		0º	90º
PRE Amp. POST Amp.				Supervision
Metal loss	Master Slave
compensation			NO C NC	On Off
	Priority input		1	2
AGC Limiter 5K	10K		Phantom	Phantom

AGC	0
100V		Vox	Mix	On	Off	Mic	Line	On	Off	Mic	Line

Line fuse: 230V 3A 115V 6A

Loop

Out Com

115V 230V

Apparatus delivered Connected for 230V

25 24 23

22

21

20

19

figure 1.3: Front and rear views

Priority	100V
input	0

	Phantom
	Mic	Bal. input
	1	Vox	Mix
	Line
	Mic	Bal. input
	2	Mute
	Line

		Master in
Tone	0º
Priority	Limiter
control	90º
		Slave out

Master

Out

Com

90º 0º

figure 1.4: Block diagram

Bosch Security Systems | 2007-08 | 9922 141 50672en