DPA-2FX User Manual
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version 1.8
page 6
3. DPA-2FX Differential Amplifier / Filter Module
3.1. DPA-2FX
Components
The following items are shipped with the DPA-2FX system:
Amplifier / Filter module for the EPMS-07 system
User manual
3.2. System
Description
The DPA-2FX differential amplifier/filter is a plug-in unit for the npi EPMS-07 modular
system. The DPA-2FX is designed to amplify and filter small bio-electrical signals. The input
voltage range is ±12 V, the inputs are protected up to 15 V. 2 overload-LEDs indicate if the
linear region of the amplifier is exceeded. All inputs and the output are BNC connectors.
The input impedance is 10 M
. Thus, the module can be used for direct recording of
bioelectric signals, e.g. from peripheral nerves. Using the differential input configuration
common mode signals and noise are removed allowing recordings of signals with small
amplitudes.
DC offsets of the signal can be compensated either by the using the OFFSET control or they
can be eliminated using the AC position of the input switches or by using the HIGHPASS
filter. DC offsets from the amplifier can be corrected by two trimpots.
The GAIN range is x1 to x10000 and can be set with two switches (1-2-5-10-20-50-100
rotary switch and 1-10-100 range switch). The output signal is passed through the
HIGHPASS and LOWPASS filter.
Important
:
To avoid noise interference the respective toggle switch should be in the zero
position if one of the inputs is not used.
3.3.
Signal Flow Diagram
The signal is passed through the DPA-2FX as shown below.
