A pulsed excitation voltage circuit for a strain gauge bridge is disclosed using a transformer having its primary winding adapted to receive an excitation timing pulse and two secondary windings to turn on two transistor switches adapted to connect positive and negative voltage sources of equal amplitude to opposite ends of the bridge. Voltage limiting diodes are connected to output terminals to limit common-mode voltage spikes resulting from different turn-on and turnoff times of the transistor switches. Each transistor switch includes a base resistor selected at time of assembly to provide substantially equal turn-on times. A speedup capacitor may be used to further equalize turn-on time, and a shunt capacitor may be used at the output of one switch to offset effects of unequal turn-on times.
A sensor circuit method of operating a vortex shedding flow meter utilizes A.C. single cycle bursts to intermittently drive a sensor which changes its state with the vortex shedding frequency. The bursts are spaced in time by an amount larger than the burst duration.
A current conduction element otherwise known as a majed circuit comprising a first PN junction. The majed circuit is also comprised of a second PN junction connected in parallel with the first PN junction but which is biased oppositely therefrom. The first and second PN junctions share common connection points such that current flows through the majed circuit in a first direction through the first PN junction but not through the second PN junction, and current flows in the majed current circuit in a second direction through the second PN junction but not through the first PN junction.
