Information subject to change
97-7224006_3-31-15
7224 OPERATOR’S MANUAL – SECTION 5
28
Remote Monitoring of Current Output -
Alternate Method
Purpose:
Use a voltage meter to monitor output
current when output is not balanced.
Method:
Connect a voltage meter to monitor
the output current being produced by the ampli-
fier. Connect across PIN 6 (IMON+) and PIN 19
(IMON-). See
Figure 5.7.
Signal Type:
AC
Level when Asserted:
7212/7224: 2.5A/V;
7548/7796: 10A/V
Level when Deasserted:
0V
CAUTION:
To avoid ground loops, isolation from
ground must be provided. Use of a differential
probe is recommended.
Conversely, when configured as a
Controlled-
Current
source (transconductance amplifier), the
amplifier will provide an output current that is con
-
stant and proportional to the control (input) volt
-
age. If the load’s impedance changes, the amplifier
will seek to maintain this transconductance (ratio
of input voltage to output current) by increasing or
decreasing the voltage it produces, as long as it is
within the amplifier’s ability to create the required
voltage. Use this mode if you want the output cur-
rent waveform to be like the input waveform (see
Figure 5.9
).
5.2 Controlled Current Operation
The procedures outlined in this section assume
competence on the part of the reader in terms of
amplifier systems, electronic components, and
good electronic safety and working practices.
5.2.1 Controlled-Voltage vs. Controlled-
Current Modes of Operation
AE Techron 7224 amplifiers can be field-config
-
ured to operate as
Voltage Amplifiers
(Voltage-
Controlled Voltage Source) or as
Transconduc-
tance Amplifiers
(Voltage-Controlled Current
Source). The mode selection is made via a jumper
setting located on the amplifier main board. See
the
“Advanced Configuration”
section for more
information.
When configured as a
Controlled-Voltage
source
(voltage amplifier), the amplifier will provide an
output voltage that is constant and proportional
to the control (input) voltage. If the load’s imped
-
ance changes, the amplifier will seek to maintain
this ratio of input to output voltage by increasing or
decreasing the current it produces, as long as it is
within the amplifier’s ability to create the required
current. Use this mode if you want the output volt-
age waveform to be like the input waveform (see
Figure 5.8
).
Figure 5.7 – Remote Current Monitoring,
Alternate Method
Figure 5.8 – Input to Output Comparison,
Controlled-Voltage Operation
