TCA-4 budget-priced 4-channel thermocouple amplifier unit.
New from Audon Electronics is the TCA-4 budget-priced
4-channel thermocouple amplifier unit. This compact
DIN-rail mounted unit has been designed to interface
thermocouples, low level sensors and 4-20mA signals
to data acquisition and process control systems.
The TCA-4 features 4 independent precision instrumentation
amplifier channels, a thermocouple cold-junction compensation
circuit and a wide input range power supply. Channel gain and
offset can be user adjusted via multi-turn presets; a gain range
from 20 to over 1000 is achievable. Alternatively the TCA-4 can
be ordered with pre-calibrated gains to suit any thermocouple
type, giving a nominal output of 10mV per degree. An on-board
temperature sensor mounted close to the input terminals can be
used to apply cold junction compensation on a channel-by-channel
basis. It is therefore possible to mix-and-match thermocouple and
low-level voltage signal types.
The TCA-4 can be used with 4-20mA process control signals too.
A burden resistor is used to convert the 4-20mA current into a
voltage, and the amplifier offset control is used to trim-out the
static 4mA voltage component. Hence it is possible to convert
the 4-20mA signal to a zero to full scale voltage signal.
The TCA-4 can be powered from a single 5V supply or a 9-28V
supply. An on-board DC-DC converter provides a ±15V supply
to the amplifiers, giving a usable amplifier output range of over
±13V. The TCA-4 is reverse polarity and over-voltage protected
in case of power supply or wiring errors.
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May 2003
