Aetechron 7224 Manual

Parallel Amplifier System Set-up Instructions
For AE Techron 7224, 7548 and 7796 Amplifiers
574.295.9495 | www.AETechron.com
2507 Warren Street, Elkhart, IN 46516

PARALLEL AMPLIFIER SYSTEM SET-UP INSTRUCTIONS
8-11 Information subject to change 2
Table of Contents
Table of Contents........................................................................................................................................................2
Introduction ................................................................................................................................................................3
Special High-Frequency Applications........................................................................................................................... 3
Parallel Operation .......................................................................................................................................................3
1. Access the Main Board .................................................................................................................................... 4
2. Master/Slave Settings ..................................................................................................................................... 4
3. Verify CV Setting............................................................................................................................................... 4
4. Remove Output Cables.................................................................................................................................... 4
5. Enable Amplifiers ............................................................................................................................................. 5
6. Measure Voltage .............................................................................................................................................. 5
7. Power Down ..................................................................................................................................................... 5
8. Reconnect ........................................................................................................................................................ 5
9. Measure Current .............................................................................................................................................. 5
List of Figures
Figure 2.1 –Circulating Ground Current Bleed Resistor ........................................................................................3
Figure 2.2 –7224 Access Panel Screw Locations..................................................................................................4
Figure 2.3 –Master / Slave Setting.........................................................................................................................4
Figure 2.4 –CC / CV Setting.....................................................................................................................................4
Figure 2.5 –Slave Gain Trim ....................................................................................................................................5
Figure 2.6 –IMON Current Monitor .........................................................................................................................5

PARALLEL AMPLIFIER SYSTEM SET-UP INSTRUCTIONS
8-11 Information subject to change 3
Introduction
These instructions outline the steps needed to set up a pair of AE Techron 7000 Series amplifiers connected
in parallel configuration. The wiring connections required between the two amplifiers are covered in the Tech
Note: Configuring Multiple Amplifier Systems.
This document assumes that all factory set-up, burn-in and life testing have been performed, and the
amplifiers are in good working order. The paralleled amplifiers must be of the same model. DO NOT try to
parallel two different amplifier models together as this will result in damage to one or both amplifiers.
This document also assumes significant competence on the part of the reader in terms of amplifier systems,
electronic components, and good electronic safety and working practices.
Special High-Frequency Applications
The set-up instructions provided here are valid for use with frequencies up to 20 kHz. For uses greater than
20 kHz, please contact AE Techron Technical Support for additional set-up instructions.
Parallel Operation
An AE Techron 7224, 7548 or 7796 amplifier may be
paralleled with a matching 7224, 7548 or 7796
amplifier to increase the available output current to the
load. To connect two 7000-Series amplifiers in parallel,
one amplifier must be configured as the “Master” and
the other amplifier must be configured as the “Slave.” In
Slave amplifiers, the input signal, selection of CV or CC
operation, and (if applicable) CC compensation are
controlled by the Master amplifier. Amplifiers are
factory-set as Masters. The Master setting is also
correct for single amplifier operation.
NOTE: Before using these amplifiers (either alone or in a
parallel system), ensure that the 2.7 ohm circulating ground current bleed resistor is installed between the
Sampled Common and Chassis Ground on the output connector (see Figure 2.1). The purpose of this
resistor is to reduce noise caused by small circulation ground currents.
Figure 2.1 –Circulating Ground Current Bleed Resistor

PARALLEL AMPLIFIER SYSTEM SET-UP INSTRUCTIONS
8-11 Information subject to change 4
To configure two amplifiers for Master/Slave operation,
complete these steps:
1. Access the Main Board
IMPORTANT: Before accessing the Main Board, make sure the
amplifier is turned off for at least 3-5 minutes and the AC mains
are disconnected.
For 7224 Amplifiers:
1. The 7224 amplifier contains an Access Panel
built into the top cover (see Figure 2.2). Locate
the Access Panel and make sure that all 8
screws are accessible. Remove the unit from
its rack, if necessary.
2. For your convenience, a #2 Phillips screwdriver
is provided in your Toolkit for use in this
procedure. Using the screwdriver, remove the
8 screws located on the top and side of the
amplifier.
3. Remove the Access Panel and set it aside.
For Other 7000-Series Amplifiers:
1. With power to the amplifier turned off, loosen
the four Allen head screws on the front cover
of each amplifier and remove the front covers.
2. Master/Slave Settings
1. For each amplifier, locate the jumpers P1 and P2
on the main circuit board (see Figure 2.3).
2. Move both jumpers to the MASTER position for
Master operation for one amplifier, and to the
SLAVE position for Slave operation for the other
amplifier.
3. Verify CV Setting
1. For each amplifier, locate the jumper J4 on the
main circuit board (see Figure 2.4).
2. Ensure that both the Master and Slave amplifiers
are set to CV (Controlled Voltage) mode via the
jumper J4 setting.
4. Remove Output Cables
Figure 2.4 –CC / CV Setting
Figure 2.2 –7224 Access Panel Screw Locations
Figure 2.3 –Master / Slave Setting

PARALLEL AMPLIFIER SYSTEM SET-UP INSTRUCTIONS
8-11 Information subject to change 5
Temporarily remove the output cable from the OUTPUT terminal of each amplifier. Leave the SAMPLED
COMMON cable connected to both amplifiers.
5. Enable Amplifiers
Enable both amplifiers. Inject a DC voltage into the input of the Master amplifier that results in an output of
approximately 80 volts DC.
6. Measure Voltage
Using a digital multimeter, measure the voltage between
the OUTPUT terminals of the Master and Slave amplifiers.
The measured voltage should be near zero volts; this
would indicate that both amplifiers are producing the
same output. To adjust this voltage, or null it out, adjust
the Slave Gain Trim on the Slave amplifier (see Figure
2.5). Adjust the Slave Gain Trim until the voltage is as
close to zero as possible; however, a difference voltage of
50 mV or less is acceptable.
7. Power Down
Remove the input signal from the Master amplifier and
disable both amplifiers.
8. Reconnect
Reconnect the load OUTPUT cables to both amplifiers.
9. Measure Current
Enable both amplifiers and inject an AC or DC signal
into the input of the Master amplifier that results in an
output of approximately 10 amps of current from each
amplifier. The output current can be measured using a
current clamp meter or using the IMON (TL4) current
monitor of each amplifier (see Figure 2.6). If using a
current clamp meter, attach the clamp meter between
the amplifier OUTPUT terminal and the ballast resistor.
The current from each amplifier should be equal; if not,
readjust the Slave Gain Trim on the main board of the
Slave amplifier until the two currents are equal.
Figure 2.5 –Slave Gain Trim
Figure 2.6 –IMON Current Monitor