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PAM-195-P-S3
4.2
Typical system structure
This minimal system consists of the following components:
(*1)
proportional valve
(*2)
hydraulic cylinder
(*3)
power amplifier PAM-195-P-S3
(*4)
interface to PLC with analogue and digital signals
(*5)
power input, from pressure sensor or pump
4.3
Method of operation
This power amplifier is controlled by an analogue signal (from the PLC, from a joystick or a potentiometer). An
ENABLE signal (typically 24V) activates the module and the READY output indicates this, if no internal or ex-
ternal error was detected.
The integrated standard functions will be configured via different parameters.
In case of a fault, the power output stage will be deactivated and the fault will be indicated through a deac-
tivated READY output and a flashing READY LED.
The output current is closed loop controlled whereby a high accuracy and a good dynamic will be obtained. All
custom proportional valves (up to 2,6A) may be controlled with this power amplifier.
This modified module is basically controlled by an unipolar command signal in the range of 0... 10V or 4...
20mA. A switching input is used for changing direction. By this way directional valves can be controlled via in-
expensive unipolar plc outputs. Special feature of this module is the power limitation function. For that an up-
per limit for each direction can be preset. Due to reducing the flow rate depending on the actual pressure this
limits will observed. Via this calculation for power limitation the output value (the flow) will be reduced:
𝑂𝑢𝑡𝑝𝑢𝑡
𝐿𝐼𝑀
=
𝑃𝐿
𝑉
∙ 100%
𝐼𝑁𝑃𝑈𝑇
𝐷𝑟𝑢𝑐𝑘
INPUT
means the measured signal for power limitation (e.g. the pressure) and
PL
V
(parameter PL:V) the
power factor in % related to the maximum. The output signal will be limited down to the
OUTPUT
LIM
value.
