97-2105006_4-2-15
Information subject to change
23
2105 OPERATOR’S MANUAL –
SECTION 6
6 Applications
6.1 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.
6.1.1 Controlled-Voltage vs.
Controlled-Current Modes
of Operation
AE Techron 2105 amplifiers can be field-
configured to operate as
Voltage Amplifiers
(Voltage-Controlled Voltage Source) or as
Trans
-
conductance 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 6.1
).
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 6.2
).
6.1.2 Safety and Operation Consid-
erations 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.
Figure 6.1 – Input to Output Comparison,
Controlled-Voltage Operation
Figure 6.2 – Input to Output Comparison,
Controlled-Current Operation
