Abstract: An angular rate sensor comprises a wafer of silicon etched to form tines with teeth which are interdigitated. The tines are excited into oscillation in the plane of the wafer, by applying suitable drive signals to create electrostatic forces between the tines. Rotation of the tines out of the plane of the wafer is detected by a suitable detector, such as a piezo-resistor on a support of the tines.

Abstract: In order to compensate for the effects of temperature variations on a transducer such as a piezo-resistive bridge, the bridge is fed from a temperature dependent power supply circuit. The power supply circuit comprises a temperature sensitive element with first and second adjustment means for adjusting the slope of supply voltage for the transducer against temperature on first and second sides, respectively, of a predetermined temperature. The second adjustment means provides an adjustment which is independent of the first adjustment means so that repeated temperature cycling during calibration is unnecessary.

Abstract: An output of a first amplifier is coupled to the input of a second amplifier by a coupling capacitor. A resistor connects one plate of the coupling capacitor to a reference voltage supplied by a potential divider. A field effect transistor is connected across the resistor with its gate connected to the connection between a further resistor and a further capacitor which are connected in series between power supply lines so that the coupling capacitor is rapidly charged when power is applied.