Signal Conditioner Boards

GAGE 3001 General Purpose Transducer Interface Board

Introduction: The GAGE 3001 is a Miniature Interface Board, used for interfacing any bridge-type Transducer such as Strain Gage, Pressure Sensor 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 3001 provides a Variable Excitation, capable of deriving upto 80mA, 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 3001 also contains an Instrumentation Amplifier, with a variable gain of 150 - 1,500 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:

The GAGE 3001 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 adversely affect the linearity of the bridge, therefore it is recommended to correct the high offset by fixing the transducer.

The Excitation of the GAGE 3001 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 3001 requires an External Stabilized Power Supply of ±8V to ±15V. An Optional Battery Power Supply can also be supplied.

The GAGE 3001 is pin compatible with the Gage 3001 Interface Card in all Inputs, Outputs and Power Supply Lines.

The GAGE 3001 has Wider Bandwidth, Lower Noise and Lower Drift than the GAGE 3000.

1. Features:
2. For use with any bridge-type Transducers, Pressure Gages, Strain Gages, etc.
3. High Gain - 1,500 standard, upto 10,000 Optional.
4. Ultra High Input Impedance - 1GW
5. High Frequency Response: upto 50kHz.
6. Built-in User Programmable Low Pass Filter
7. Built-in Excitation
8. High Common Mode Rejection - 120dB min.
9. Low Noise, Low Offset and Drift
10. Low Cost


11. Applications:
12. Weighing Systems
13. Interfacing of Load Cells to A/D cards
14. Amplification of Low Level Sensors (Pressure Transducers, Light-sensing Devices, Thermistors, etc.)
15. Medical Applications: EEG, ECG, etc.

1. Specifications: