GAGE-3000
General purpose transducer signal conditioning board
Actual size: 70.5 X 30.5mm
Introduction
The
GAGE-3000 is a high quality interface board, used for interfacing any bridge-type
type transducer such as Strain Gages, Pressure Sensors and other bridge-type
transducers, as well as voltage producing devices such as Piezo Sensors, Temperature
Sensors, Photo Diodes and EEG/ECG inputs.
The GAGE-3000 provides a variable excitation, capable of driving up to 80 mA, at voltage range of 1V to 20V. The excitation voltage is symmetrical about ground level, so that the common mode voltage is approx. 0V. For example: an excitation voltage of 12V will be ±6V relative to ground.
The GAGE-3000 can be configured as a single board for one transducer or up to six transducers on a single board.
The GAGE-3000 also contains an Instrumentation Amplifier, with a variable gain of 200-1500, and a variable offset control. The output of the Instrumentation Amplifier is fed to a double pole Low-Pass-Filter, then passed via a driver buffer to the output port. The cut-off frequency of the Low-Pass-Filter may be changed by replacing two capacitors, CX1 and CX2, with capacitors of other values. The following Table provides capacitors values for some often used cut-off frequencies:
Cut-Off Freq. | 50 Hz | 100 Hz | 200 Hz | 500 Hz | 1 kHz | 2 kHz | 5 kHz | 10 kHz | 20 kHz |
Capacitor Value CX1/CX2 |
330 nF | 150 nF | 80 nF | 33 nF | 15 nF | 8 nF | 3.3 nF | 1.5 nF | 1 nF |
The GAGE-3000 also has a bridge loading resistor Rx, connected in series with a variable trimpot (variable resistor) designated P2. The resistor is used for correcting the offset of a bridge, which has a high offset level that cannot be corrected by using the on-board offset control. This resistor has to be defined and connected by the user. Please note that this resistor may affect the linearity of the sensor, therefore it is recommended to correct the high offset by fixing the transducer.
The excitation of the GAGE-3000 may be changed by using a trimpot designated P6, while the excitation level may be measured between the -EXC and +EXC test points. The gain is adjusted using P1.
The GAGE-3000 requires an external stabilized power supply of ±8V to ±15V. We offer an optional battery power supply that works from a 12V battery.
Figure 1: Block Diagram
For
use with any bridge-type transducers, pressure gages, strain gages, etc.
High
gain - 1500 standard,up to 20000 optional.
Ultra
high input impedance - 1 GW.
High
frequency response - up to 120kHz.
Built-in
user-programmable Low Pass Filter.
Built-in
excitation.
High
common-mode rejection - 115dB min.
Low
noise, low offset and drift.
Low
cost.
Applications
Weighing
systems.
Interfacing
of load cells to A/D cards.
Amplification
of low-level sensors (Pressure Transducers, Light-sensing Devices, Thermistors,
etc.)
Medical
applications: EEG, ECG, etc.
Technical
Specifications
PARAMETER |
VALUE |
Gain | 100-1500 (adjustable by user) up to 10,000-by request |
Gain Non-Linearity | ± 0.002% |
Gain Temp. Coef. | 5 ppm/C° |
Input Offset Drift | 1 µV/C° |
Output Offset Drift | 25 µV/C° |
Input Offset Vs. Supply | 85 dB |
Input Impedance | 1G![]() |
Dift. Capacitance | 5 pF |
CMRR ( DC - 100 Hz ) | 100 dB |
Bandwidth ( Gain 100 - 1000 ) | 20 kHz min. (-3 dB) |
Setting time to 0.01% | 80 µ Sec. |
Input Noise Voltage (@ 1 kHz) | 5
nV/![]() |
Output Noise | 100
nV/![]() |
Supply Voltage Range | ±8V to ±15V |
Excitation Level | ±1V to ±10V |
Excitation Current (max.) | 80 mA |
Excitation Drift | 15 ppm/C° ±10 µV/C° |
Excitation Noise (DC - 100 kHz) | 0.6 mV max (@300R load) |
Excitation Noise (DC - 1 kHz) | 0.2 mV max (@300R load) |
Operating Temperature | 0 - 70 C° |
Bridge Resistance Range | 50 ![]() ![]() |
For more information about our Amplifiers and Signal Conditioner products , please click here.
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