Ampetronic ILD100DC User manual

1. It is important to read these instructions, and to follow them.
2. Keep this instruction manual in an accessible place.
3. Clean only with a dry cloth. Cleaning fluids may affect the equipment.
4. Do not cover or obstruct ventilation of this unit. Install in accordance with the
manufacturer’s instructions.
5. Do not install near any heat sources such as radiators, heating vents, or other
apparatus that produces heat.
6. Refer all servicing to qualified personnel. Servicing is required when the
apparatus has been damaged in any way, such as a power supply cord or
plug is damaged, liquid has been spilled or objects have fallen into the
apparatus, the apparatus has been exposed to any rain or moisture, does not
operate normally or has been dropped.
7. WARNING - To reduce risk of fire or electric shock, do not expose this
apparatus to rain or moisture. The apparatus shall not be exposed to dripping
or splashing and no objects filled with liquids, such as vases, shall be placed
on the apparatus.
ILD100DC HANDBOOK
Box Contents
1 x ILD100DC
1 x Installation & Commissioning
Handbook
1 x Power Cable
1 x Designing Induction Loops Handbook
1 x AC to 12V Power Adapter
DC
1 x A6 Induction Loop Logo
1 x DC PSU Handbook
1 x Drilling Template
Handbook Contents
!
!Introduction
!Quick Start
!Overview
!Installation
!Troubleshooting
!Accessories
!Technical Specification
!Warranty
!Declaration of Conformity
Safety
The Lightning bolt triangle is used to alert the user
to the risk of electric shock.
SAFETY:
This symbol is used to alert the user to important
operating or maintenance instructions.

For those who have a good appreciation of loop systems, the following is a
very quick guide to setting up the amplifier:
All you need is a power source, a signal source and a loop. See ‘Designing
Induction Loops’ handbook (supplied) or contact Ampetronic for advice.
Installation
1. Turn all controls fully anti-clockwise.
2. Connect loop cable of appropriate length / gauge.
3. Connect signal input(s).
4. Connect power.
Operation
5. Switch on. Check green Power LED is illuminated.
6. Apply input signal and increase the input control until the Compression
LED begins to light.
7. Adjust the Drive control until the Loop Current LED begins to light on the
peaks of the signal.
8. Repeat step 6 for the other inputs if used.
9. Listen to the magnetic field produced inside the loop area using a
receiving device (e.g Ampetronic ILR3), or examine the performance in more
detail with a suitable field strength meter.
10. Adjust the TONE control to achieve a flat frequency response.
QUICK START
INTRODUCTION
The ILD100DC has been has been designed as a high quality amplifier for
small to medium size induction loop systems in places such as video
conference facilities, meeting rooms, small seminar rooms, TV rooms,
nursing homes, private homes, reception and waiting rooms.
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The ILD100DC can cover areas up to 120m for a square loop and greater
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than 200m for a rectangular loop configuration.
The ILD100DC has two microphone inputs suitable for electret microphones
and twin Phono line inputs suitable for direct connection to a TV set via
SCART style connection, or connection to a Hi-Fi system. The unit has VOX
switching capabilities which are controlled by selecting appropriate switches.

OVERVIEW
LOOP output connector.
DC POWER: connector.
I/O: Power switch.
MICROPHONE inputs: 3.5mm mono jack connectors.
LINE input: Twin RCA (Phono) connectors, for stereo connection.
VOX MODE SWITCH: Switches 1,2 & 3.
MICROPHONE1, 2 and LINE: Screwdriver adjustable controls which set
the gain and level of signal fed to the compressor.
. DRIVE: Screwdriver adjustable control which sets the level of output
current delivered to the loop.
TONE: Screwdriver adjustable control allowing adjustment to the system
frequency response.
Compression LED: shows input signal has reached the compression point.
Loop current LED: indicates when current is running into the loop.
Power LED: Indicates power is applied to the unit and is switched on.
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LOOP POWER
LINE
LINE
MODE
SWITCH
MICROPHONE 1
DRIVE TONE
MICROPHONE 2
Power
Loop Current
Compression
1 2
MICROPHONE
For Mode Switch settings
see the Instruction Handbook
INDUCTION LOOP DRIVER ILD 100DC
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Designed and Manufactu red in Engla nd by
AMPETRONIC Ltd.
LOOP RESISTANCE 0.2 - 0.8 W
Power 20W max 12V DC

ILD100DC Block diagram
MIC 1 gain
+12V
Power
Supply
Power
LED
DC Power
0V
POWER
Mic I/P 2
Mic I/P 1
LINE I/P
MIC 2 gain
TONE
Compressor
DRIVEOutput
LOOP
Compression
LEDLoop Current
LED
MICROPHONE
INPUTS
MODE
SWITCH
LINE gain
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OVERVIEW cont’d
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MICROPHONE inputs: 3.5mm mono jack connectors.
LINE input: Twin RCA (Phono) connectors, for stereo connection.
VOX MODE SWITCH: Switches 1,2 & 3.

INSTALLATION
Location:
"When installing this equipment ensure adequate ventilation as the
equipment dissipates heat during operation.
"The unit can be placed freestanding, or wall mounted using two No 8 Round
Head wood screws fitted to suit the rear hole pattern. The screws are
positioned at 160mm separation in a vertical line. The drilling
template supplied will assist in correct positioning.
Choice of loop Cable:
"The maximum DC resistance of the loop should be greater than 0.2W for
optimum performance, but should be less than 0.8 W .
"The cable from the loop to the ILD100DC output terminals MUST be a
twisted pair. If this is longer than 10 metres, contact Ampetronic.
Tools & Equipment:
"Small hand tools including a wire stripper and a small flat bladed
screwdriver.
"An ILR3 loop receiver or a magnetic field strength meter is vital to check that
the loop system is providing the desired level of performance.
System Requirements:
"The induction loop cable itself should be already installed according to the
“Designing Induction Loops” handbook, or as per specific design
instructions provided by Ampetronic. As a result, a target peak
current should be known, based on achieving acceptable field
strength across the area to be covered.
Microphone Inputs:

"
supplied with the equipment. Power for the microphone is supplied from
the equipment. Some unbalanced electret microphones with internal
battery can be externally powered if this internal battery is removed. Many
microphones of this type are adversely affected by the external DC power,
even when using their internal batteries. In all these instances, careful
investigation will indicate whether a microphone is suitable.
"Dynamic microphones cannot normally be used with the equipment because of
the much lower signal level, also the DC bias seriously impairs the
performance of the microphone. Ampetronic can supply a special adaptor
which permits the use of dynamic microphones (and electrets which are
affected by the DC bias).
"The cable length on this input must not exceed 3 metres, as unbalanced
microphone lines are susceptible to interference. EMC compliance is only
met for this cable length. The above mentioned adaptor converts the input
to a balanced line, which can be extended to longer distances.
Line Input:
"A twin phono input is fitted to the unit, allowing a direct connection to the Left
and Right channels of the SCART signal, or the output from a HiFi system.
It is also possible to connect the line-level output of another sound system
to this input.
"Maximum cable length on this input should be less than 3 metres so as to
ensure EMC compliance.
Connection & Set-up:
During the initial commissioning of the equipment it is essential that the following
procedure be used to ensure a satisfactory end result.
1. Turn the MICROPHONE, LINE and DRIVE controls fully anti-clockwise,
i.e. minimum signal, and set the TONE Control to mid-range position.
2. Provide a continuous input signal, preferably from a small tape/CD player
with speech or music, connected to the LINE input.
3. Increase the LINE control until the compression LED illuminates under
peak signal conditions. This establishes a reference level for the output
power driver.
4. Increase the DRIVE setting until the desired output current is achieved. If
no reading is obtained, check for loop continuity.
5. Listen to the magnetic field produced inside the loop area using a
Both inputs are designed to be used with an unbalanced microphone as

receiving device (e.g Ampetronic ILR3), or examine the performance in
more detail with a suitable field strength meter.
6. From this point onwards, the DRIVE control will not need re-adjusting, as
this only affects the peak field strength.
7. Connect the cable from the audio system to the line input, and re-adjust
the input gain control for optimum compression. If only the microphone
input is used directly without another sound system, then set up the entire
system from a normal sound source activating the microphone(s). Ideally,
adjust the MICROPHONE input with the lowest level of sound.
8. At this point the TONE control can be adjusted to give the best frequency
response, which can be checked with an ILR3 or field strength meter.
Setting of input controls - Optimising Compression - VOX levels.
In order to obtain the greatest possible dynamic control range from the
compressor it is now necessary to establish the highest level of input signal
which the equipment may receive in the operational installation. This will
often be loud, close talking into a microphone.
It should be pointed out here that background hum and noise from equipment
earlier in the chain, such as a sound or TV system may sound unpleasant
when subjected to some 20-36dB extra amplification.
When this occurs, the gain must be kept at a lower, acceptable level. Where
the dominant signal is music, then it may be important to keep the
compression level low, to prevent serious degradation of the music
dynamics. Experience will indicate which level to use.
REMEMBER: once the DRIVE control has been set, only adjust the
MICROPHONE or LINE control, as otherwise the correct operation of the
equipment is impaired.

Voice Controlled switching (VOX)
There are 3 MODE select switches for the VOX switching features of the
ILD100DC. These switches are located on the top edge of the unit alongside
the input connectors. See Overview. The MODE select switches enable their
respective functions when in the 'ON' position (the switch is down, towards
the base of the unit).The mode select switches may be used in the
combinations shown below to achieve the required effect.
The VOX threshold is at the onset of compression, and as such is
automatically set by the MICROPHONE and LINE controls.
Switch
Position signal is higher than signal is lower than
VOX threshold VOX threshold for > 5
1 2 3 seconds.
off off off Vox switching disabled -
all inputs operate normally
off off on Microphone 1 input on. Microphone 1 input off.
off on off All inputs attenuated by All inputs at normal
15dB except Microphone 1 levels
off on on All inputs attenuated by All inputs at normal
15dB except Microphone 1 levels except Microphone 1
input off
on X X Reserved for future use.
Effect when Microphone 1 Effect when Microphone 1

TROUBLESHOOTING
No power LED: Check that power has been connected to the unit
and the POWER is switched on (I/0 button pressed
in).
Check Mains power connector fuse.
Check Mains power is available at the socket.
No Compression LED: Check that a microphone or signal source is
connected and the corresponding input control has
been set. Check VOX switch settings.
No Loop Current LED: Check that the compression LED is illuminated.
Check that the Drive control has been set.
Check that the loop cable is properly connected and
is not open circuited; check with a suitable
multimeter that the resistance of the loop is between
0.2 and 0.8 Ohms.
Instability or high frequency noise:
1. It is possible for the loop cable to become shorted to ground under fault
conditions, resulting instability which may sound like high frequency noise,
buzz or whistling.
The results of this type of fault are likely to cause the unit to overheat. This
fault is easy to determine. Simply disconnect the loop cable from the
amplifier and test with a resistance meter between the loop cable and earth.
There should be an open circuit measured between the earth/chassis and
cable, if not, investigate the fault.
2. Instability can be caused by using poor quality signal cables, long
unbalanced (2-wire) signal runs to the inputs, or by running input cables in
close proximity with the loop wire over any appreciable distance.
Loop amplifiers are capable of delivering high currents at audio
frequencies. If the loop cable is run close to sensitive signal cables it may
be possible to induce a signal back into the input of the amplifier causing
feedback. Cable runs and loop wires should be kept well apart from each
other. To avoid interference a proximity of 300mm should only be run for a
few meters.

Interference
1. Background magnetic field signals or interference may be present in
any location and may not be anything to do with the loop system.
Monitor this with a loop receiver (such as an ILR3). If the interference
is still present with the loop system switched off, then you need to
locate and eliminate the source of interference before switching the
loop system back on.
2. AC power hum can be introduced into the system if signal cables are
grounded at multiple points. This can cause earth currents to flow
around the screen wires of signal cables and introduce unwanted noise
into the audio path.
3. Magnetic fields can be induced into any low impedance electrical path
or loop. Multiple ground earth systems may experience the pick up of
the loop signal, and cause difficulties with other systems that are not
designed to reject such interference. Check entire sound system for
evidence of loop signal, and trace source of pick-up.
4. Under certain circumstances, the loop signal may appear as jagged
lines or hum bars on a CCTV picture. This could be due to running
CCTV (low impedance unbalanced 2-wire circuit) cables in close
proximity to the loop cable. Separate the cables to reduce the effect.
5. Remote (and apparently unconnected) PA systems can sometimes
pick up loop signals. This is usually because the loop cable becomes
damaged (see point 1 of Instability) or induces signals into the remote
system through long unbalanced cables. Always run long audio signal
cables as 3-wire balanced circuits & keep away from loop cables.
6. See also point 1 of Instability.
ACCESSORIES
Details of all products & services provided by Ampetronic can be found at
www.ampetronic.com
Desktop Microphone EM195A, or Boundary Microphone Q400, or Tieclip
style Microphone EM336, are available if required.
18mm
Ø 10.0mm
43mm
23mm
EM 195A
93mm
76mm
Tie Clip MicBoundary MicDesk Top Mic

ILD100DC Power Supply:
Supply range: 12-15VDC
Nominal voltage: 12VDC
Fuse: T 1.6A L
Supply currents (with nominal voltage):
Nominal (pink noise): 900mA
Quiescent: 100mA
Maximum: 1.6A
'DC IN' terminal:
Centre positive (+) concentric socket.
Ø = 5.5mm/2.1mm. IP rating: IP20.
12V Power Adaptor Supply (AC):
DC
Refer to markings on unit supplied. Physical: Weight: 0.82kg
Must be capable of delivering 1.5A from Width: 124mm
12V output.
DC Depth: 216mm
Height: 44mm
Options:
Microphone options - see
Assessories.
Frequency Response:
Measured at low level with no
metal loss correction.
80Hz to 6.5kHz -3.0dB.
Environmental:
Ventilation: See Installation
section for details.
0
Ambient temperature: 0C to +35 C
Relative Humidity: < 90%.
MICROPHONE Input:
2 x 3.5mm mono inputs.
Input Impedance: 8kW.
Sensitivity: -60dBu (775uV )
RMS
for full output.
Overload: >-12dBu (200mV ).
RMS
Standards:
LINE Input: Meets relevant CE, EMC and
Twin RCA (phono) inputs. safety standards.
Input Impedance: 20kW between
each input 60kW single input. Please contact Ampetronic if you
Sensitivity: -30dBu (24mV ) need further assistance.
RMS
for full output.
Overload: >+10dBu (2.45V ).
RMS
Compression (AGC):
>36dB dynamic range.
Controlled by adjusting input level.
Loop Design:
Depends on application, see
Designing induction loops
handbook(supplied) or
consult Ampetronic.
Output:
Current: >4.5A peak into 0.8W.
Voltage: >4V peak.
Loop Resistance: 0.2W to 0.8W
resistive or 1.0W max impedance
reactive at 1.6kHz.
THD+N <0.5% @ 1kHz @ 4.8Apk
TECHNICAL SPECIFICATIONS

This product carries a five year parts and labour warranty from date of
shipment from Ampetronic. To qualify for the five year warranty, the product
must be registered at (products/warranty), without
which the warranty will be valid for two years only.
The warranty could be invalidated if the instructions in this handbook are
not followed correctly, or if the unit is misused in any way.
www.ampetronic.com
Note: The power adaptor supplied with this product is only covered by the
manufacturers warranty period.
Manufacturer: Ampetronic Ltd.
Northern Road,
Newark,
Nottinghamshire.
NG24 2ET
United Kingdom.
Declares that the product:
Description: Induction Loop Driver
Type name: ILD100DC
Conforms to the following Directive(s) and Norm(s):
Directive 2004/108/EC
EMC: EN55103-1 : 2009 Emission
EN55103-2 : 2009 Immunity
Directive 2006/95/EC
Safety: EN60065 : 2002
Date: January 2011
J.R. Pieters
Managing Director
Ampetronic Ltd.
WARRANTY
DECLARATION OF CONFORMITY
UP16002-1