Practically in all Waddan’s sensors, the front end where the physical measurement is transformed into a signal consists of analog electronics. The only exception is the digital accelerometer, where the acceleration input as it incrementally crosses different thresholds; it keeps on closing different switches. On the other hand, practically all systems mostly employ digital electronics. Examples of Waddan’s electronics offered with sensors and systems are as follows:
A switch capacitor is used with the pickoff impedance bridge shown on the left to determine the displaced position of the proof mass. This test board employs only an integral control. A PWM forcer through the switches provides the forcing action. This type of servo lends itself to up/down counts as the sensor output (eliminating the need for an AtoD converter prior to interfacing with system digital electronics).
Waddan’s PFOG hybrid package electronics is implemented with an ARM9 Microprocessor. This MIOC for this gyro has two differential modulators—one for bias phase shift to operate the gyro always at its peak sensitivity, and a second one to null the Sagnac phase shift developed under an applied angular rate. A couple of DACs are used to implement these servos. It also controls the LED current for wavelength stabilization. A third DAC is dedicated to the tuned Y-junction for 50/50 split of the light into two counter rotating parts.
