Microstrain

DEMOD-DC®

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DEMOD-DC®

Carrier Amplifier-Oscillator/Demodulator for DVRTs®; Inductive, Capacitive and Resistive Bridge Circuits.

Overview

The DEMOD-DC® in-line signal conditioner makes DVRT® sensors as easy to use as a potentiometer. With integral signal conditioning electronics, the user connects power, ground and analog out, and the DEMOD-DC® outputs a buffered, high-frequency response voltage proportional to linear position. During the manufacturing process the analog output voltage is digitally trimmed, ensuring that every DVRT®’s offset and gain values match one another. The DEMOD-DC® provides internal power regulation and reverse polarity protection, and will operate with a wide range of input voltages.

Operating from a DC power supply, the DEMOD-DC® Miniature In-line Signal Conditioner filters incoming transients from the power supply, and supplies a sine wave excitation to the DVRT®. This excitation is used to measure minute impedance changes of the sensing elements. Precision demodulator components provide rectification and differential amplification. Digital trimming ensures conformity from sensor to sensor. The analog output is filtered and buffered to provide clean, high level signals.

The DEMOD-DC® is recommended for use with all standard MicroStrain® DVRT® where a lower cost and smaller size signal conditioner is required. If the sensor is expected to be exposed to thermal gradients across its sensing coils (its body), the temperature compensated DEMOD-DVRT® -TC is recommended. Additionally, if the MicroStrain® DVRT® has been customized and built with one coil, the DEMOD-DVRT® -TC is again recommended.

Typically, a DEMOD-DC® is ordered with a specific MicroStrain® DVRT® and sold as a pair. The pair is calibrated together at the factory and delivered with a common calibration certificate. This ‘paired’ calibration ensures accurate performance in the user’s hands. The certificate provides several output calculations including Linear Fit, Multi-Segment Fit and Polynomial Fit.

Demod-DC Signal Conditioner
Applications

Used with MicroStrain DVRT® sensors for:

  • miniature control elements for automotive and robotic systems
  • process control for production-line monitoring
  • dimensional gauging for quality control applications
  • measuring strain and deflection in materials science and civil structures
  • linear/angular positioning of optical components
  • miniature force, torque, acceleration sensors
  • measuring strain, micromotion and deformation in bone and tissue
  • miniature size enables the signal conditioner to be located close to the transducer
  • simple three wire connection provides easy plug and play implementation
  • compatible with all DVRT® sensors
  • configuration available for MicroStrain mXRS™ wireless sensors
  • low cost, rugged, compact design suitable for OEM applications
  • digitally trimmed offset and gain
  • frequency response up to 20 kHz
  • operates on wide range of input voltages
  • low power consumption allows battery operation
Sensor Types inductive (DVRT®)
Excitation regulated sinewave, 150 kHz standard other frequencies available on request
Demodulation asynchronous, DC output
Output 0 to 5 V typical, digitally trimmed
Gain factory adjustable from 10 to 10,000
Low pass filter 2 Pole, 3 dB down @ 800 Hz standard factory adjustable 10 Hz – 20 kHz
Supply voltage + 6.0 to + 16 volts DC
Supply current 22 mA typical (15 mA when modified for use with MicroStrain V-Link® or DVRT-Link™ wireless nodes)
Warm-up time 30 seconds recommended
Operating temperature -40 to +85 °C
Enclosure size 65.7 mm x 19.9 mm x 8.3 mm
Connections power, ground, analog output
Connector micro-D (MIL-C-83513/5) mating connector included
Weight 12.02 g

How To Order

To discuss configuration for your specific system requirements, please contact sales at sales@microstrain.com or call  802-862-6629.

For large quantity orders or OEM discussions, please contact mirobinson@microstrain.com.

If you are outside the US, please contact one of our distributors.