The models VIB-5B-PEAK and VIB-5B-EFF provide a cost-effective method for interfacing common transducers with constant current excitation to DATAQ Instruments’ wide range of data acquisition products. These transducers, such as piezoelectric accelerometers and microphones, feature built-in signal conditioning and low impedance outputs, but do require an external excitation power supply. This must be provided as a current-mode source, since the transducer’s output resistance changes as a function of applied force or acceleration. Constant current excitation transforms this variable resistance to a variable voltage that is directly proportional to the measured phenomena.

The constant current source of VIB-5B amplifiers yields 5.3 mA DC excitation with a compliance voltage of 8 … 12 VDC. The amplifiers feature AC coupling to remove the DC component of the transducer’s signal so that only dynamic waveform information is passed through the amplifier. Gain for both amplifier models is fixed to 1, although many of DATAQ Instruments data acquisition products feature programmable gain per channel. This feature many be applied to yield greater sensitivities when required.