97-7224006_3-31-15
Information subject to change
29
7224 OPERATOR’S MANUAL – SECTION 5
Figure 5.9 – Input to Output Comparison,
Controlled-Current Operation
5.2.2 Safety and Operation Consider-
ations for Controlled Current Operation
When an AE Techron amplifier is configured as
a Controlled Current source, care needs to be
exercised in its operation.
Any voltage controlled
current source should never be turned on
without a load, (with some impedance, real or
effective) connected to its output terminals.
When asked to operate in this way, any current
source (including an AE Techron amplifier) will in
-
crease its output voltage in an attempt to drive the
requested current into the load. In an open-circuit
condition, creating current flow will be impossible.
The current source will increase its output voltage
until it reaches its voltage limit. This is a potentially
dangerous condition for both the AE Techron am-
plifier and for any user who might come in contact
with the amplifier output terminals.
When operating in Controlled Current (CC) mode,
a compensation circuit is required to ensure ac-
curate output current. Since the load is a critical
circuit component in CC mode, the inductive and
resistive values of the load will determine the
required compensation values. While the factory-
default compensation setting will be sufficient
for some applications, the compensation setting
may also be adjusted in the field. The following
section describes methods for determining and
setting proper compensation when operating in
Controlled-Current mode.
5.2.3 Controlling Compensation for
CC Operation
AE Techron 7224 amplifiers can be configured for
either Controlled Voltage (CV) or Controlled Cur
-
rent (CC) mode of operation. When operating the
amplifier in Controlled Voltage (CV) mode, com
-
pensation is not required. However, when operat
-
ing in Controlled Current (CC) mode, the amplifier
load becomes an integral part of the system. In
order to ensure system stability and to control
available bandwidth, compensation via an RC
network is required for CC operation. The following
steps will allow you to compensate your amplifier
for operation in CC mode safely and effectively.
STEP 1: Check Amplifier Operation in
CV mode.
We recommend that you power-up and enable the
amplifier in Controlled Voltage mode without at
-
taching a load before configuring your amplifier for
Controlled Current operation. This will allow you
to verify that the input signal and the amplifier are
operating correctly.
Once this initial check is completed, power down
the amplifier and access the amplifier main board
to place the amplifier in CC mode. (Refer to the
“Advanced Configuration”
section for more
information.)
One of two compensation settings can be selected
via jumpers on the main board: CC1 which en
-
ables the factory-installed RC network (see
Figure
5.10
), or CC2 which allows installation of a custom
RC network.
Figure 5.10 – Factory-installed Default RC Network
