Abstract: A threshold gate has a pair of signal comparators with each comparator being supplied with a first input signal derived from a subdivided portion of a respective polarity of a rectified form of an alternating current input signal. The comparators are also supplied directly with the alternating current input signal whereby the output signal of each comparator is the portion of the input signal above the variable threshold set by the rectified portion of the alternating current input signal.

Abstract: A dual limiter circuit for limiting an input signal between high and low limits and having a first and a second operational amplifier with the positive inputs of the amplifiers being supplied with respective threshold, or limit, signals. A third operational amplifier has its positive input supplied with an input signal to the limiter circuit. A respective output impedance for each amplifier connects the output of the corresponding amplifier to the output of the limiter circuit while a feedback connection from the limiter output circuit is connected to the negative inputs of all three amplifiers. This dual limiter circuit operates for all values of the input signal to have one of the amplifiers operating in its linear region to control the output signal from the limiter circuit while the other two amplifiers are operated in saturated states in opposite senses.

Abstract: A multiple input switching system includes an input isolation device, such as a transformer, in the input circuit. Switching devices are provided for sequentially connecting the several input circuits to a time-shared amplifier. The switching devices are actuated at a predetermined rate with a predetermined closed-time for each closure. Further switching devices are provided for transferring the data from each of the input circuits to a corresponding memory device. These further switching devices are operated synchronously with the first-mentioned switching devices but with a shorter close-time. The data values in the several memory devices may be selectively scanned asynchronously. Between each actuation of the input switching devices, additional switches are actuated which (1) short-circuits the input to the amplifier and (2) applies the output drift signal of the amplifier to a compensating storage capacitor.

Abstract: A closed system couples the inlet and outlet pressures generated by a centrifugal pump to a pair of flexible diaphragms which seal the flow tube in a pressure rebalance system for measuring fluid flow. The system is filled with a conducting fluid which forms certain resistance paths whose resistance varies with diaphragm position. This resistance change is used to generate signals which control the pump motor to the end that the diaphragms maintain a predetermined position and the pump head is equal to the differential pressure.

Abstract: A mounting arrangement for a recording head provides for an adjustment of the alignment of the face of the recording head relative to a recording medium disposed in a sliding contact relationship with the face of the recording head.