Comparison and general features of the LinearAmp system
In our choice there are three different amplifier systems. This booklet describes the
LinearAmp amplifier family. Our other amplifier products are BioAmp and MultiAmp
families. All of them are up-to-date, easy to use, highly reliable, microprocessor-
controlled constructions. We manufacture three different amplifier families, because
the three product lines are optimized for different application fields. Please read
through the appropriate descriptions at the website of Supertech for the details.
LinearAmp amplifier is optimized for high-precision signal conditioning tasks in
bioelectrical recording.
LinearAmp is a programmable amplifier, but it has (nearly) no sampling circuits in the
signal path at all, except the 8-pole switched-capacitor low pass filter. In other
words, it is controlled by a built-in microcontroller, or a remote computer, but it has
got only high-performance, low noise, low distortion analogue amplifier circuits. This
feature is indispensable when you use averaging techniques for processing its output
signal. The internal microcontroller and the optional digital port (which offers remote
control facility from a PC) are optically isolated from the amplifier stages. In this way
we could connect all the advantages of high accuracy analogue amplifier circuits, and
easy usage of digital control.
Although LinearAmp is programmable equipment, it does not need a separate
computer to work. According to this fact, it can be used as a stand-alone amplifier
(while possessing an optional serial port to communicate with a PC). This stand-alone
feature is very comfortable, because the computer is always given, but it should be
used to collect, and processing the experimental data. LinearAmp's microcontroller on
the front panel has got a 3-button keypad, and menu-driven internal software, so it is
very friendly to use.
The internal structure of LinearAmp is modular, so the number of the amplifier
channels, and the number of the microcontrollers built in one equipment can be
decided independently. Only the aspects of the application field should be considered
when we decide, how many amplifier channels, and how many microcontrollers will
be placed in the cage of the equipment (for example it is comfortable to use only one
microcontroller to program all the EEG channels together, but another controller
should be used, if there is a single unit channel in the system, and a third controller is
necessary, if there are further channels for ECG).
Independently of the number of the microcontrollers, every amplifier channel has got
their own DC offset correction circuits, even in a multi-channel system. The voltage
range of the offset correction is +/- 200 mV, with 0.1 mV of resolution. In our
choice there are two different solutions for the offset correction circuit. One of them
is the analogue version with a 10-turn helical potmeter and a digital panelmeter on
the front of the equipment. The other version is the digital realization of the same
task: a separated microcontroller, dealing with the numerical control of the offset
voltage. The actual version should be specified in the order.
