Abstract: An auto-ranging system for an electronic watt-hour meter includes a current transformer for measuring the electrical current in at least one line of an electrical power consuming system. The measured current is converted to a voltage which is proportional to the measured current by means of a current/voltage converter. A means responsive to the output of the current transformer incrementally varies the gain of the current/voltage converter inversely as the level of the measured current reaches each of a plurality of successively increasing discrete current levels. The output of the current/voltage converter is multiplied by the line voltage which is detected by a potential transformer with the output of the multiplier being coupled to an analog-to-pulse rate converter. The analog-to-pulse rate converter generates a pulse train having a pulse rate which is proportional to the product signal at the output of the multiplier.

Abstract: The invention concerns a circuit arrangement for use with an electric melting furnace of a type which is fed by a converter, the latter converter being equipped with thyristors and controlled by a control unit and a series-connected current regulator. More specifically, in accord with the invention, the circuit arrangement is provided with monitoring circuits for monitoring the operation of the thyristors. These monitoring circuits, in turn, generate signals which control switches for selectively short-circuiting the feedback resistors of the regulator.

Abstract: A bistatic velocity detector system for underwater detection of objects of redetermined magnitude wherein the water may be capable of continual variations in velocity. The system includes a compensator that has an automatic gain controlled amplifier whose controlled output signal is applied first to an a.c./d.c. converter and then to an integrator circuit. A first voltage comparator receives the integrated signal to drive a relay for activating an alarm when a threshold is exceeded. A second voltage comparator having a lower reference voltage applied thereto drives an RC timer circuit whose output signal is applied to the gate of a field effect transistor of variable impedance for varying the gain of the operational amplifier. An alternative embodiment includes a dual gate transistor for use in the gain controlled amplification of the loop.

Abstract: A segmented voltage function is generated at the output of a primary differential amplifier having an input voltage connected to the noninverting terminal. As the input voltage increases at the noninverting amplifier input, the output increases with the same slope until a voltage as sensed at the inverting input of the amplifier equals a first breakpoint. The inverting input to the primary differential amplifier connects to a feedback circuit that also includes a plurality of secondary differential comparator amplifiers coupled to a voltage ladder network. Each of the secondary differential amplifiers has a noninverting input connected to a separate voltage on the ladder network. The inverting input of each of the secondary differential amplifiers is connected to a feedback loop.

Abstract: An analog store includes a four-arm resistance bridge in which the resistance of one arm is formed by the drain-source path of a field-effect transistor. The bridge is energised across one diagonal by an alternating voltage and the output is derived from the other diagonal through a high-gain amplifier. The input is applied to the gate of the field-effect transistor. A capacitor is connected between the gate of the field-effect transistor and biasing means.

Abstract: This is a seismic digital recording system for use where the seismic amplifiers are placed near the geophone locations and their outputs transmitted by common cable to the recording truck or recorded on magnetic tape at the geophone location. In such a digital recording system, it is impractical to use a high-speed, high gain-ranging amplifier of 15 or 16 bits range. In our design the gain-ranging amplifier is high-speed but employs fewer bits total range. The extra range is made up in a preamplifier which has a variable range of gain, which can be automatically set, but at slower speed. The invention involves a control system which is responsive to the output of an A/D converter which is connected to the output of the gain-ranging amplifier.

Abstract: An automatic gain control circuit including a wide band digitally controlled amplifier particularly adapted for use with recurring signals. Each of the recurring signals is divided into a large number of discrete time intervals and the gain of the amplifier may be adjusted for each time interval independently of the signal in any other of the time intervals. Transients due to gain modification may be superimposed.

Abstract: A variable-gain amplifier comprises a transistor with an emitter connected in a degenerative emitter-follower circuit which includes a PIN diode traversed by a current injector in the form of an operational amplifier, the PIN diode forming part of a negative-feedback path extending from the output to the inverting input of the operational amplifier. To achieve a gain characteristic whose logarithm varies linearly with a control voltage, this control voltage is fed to the same inverting input through an amplifier circuit with an exponential characteristic, including another operational amplifier provided with an input transistor. A temperature-compensating circuit, preceding that input transistor, comprises still another operational amplifier having a further transistor inserted in its negative-feedback path. The variable-gain amplifier may be included in one of two conjugate (sum and difference) channels of a monopulse radar.

Abstract: A distortion measurement system for measuring distortion as low as 0.002% includes an ultra low distortion oscillator having a relatively fast response which is achieved by switching the time constant of the control loops of the oscillator during settling. The analyzer section included in the distortion system has a unique notch filter which provides low distortion. This is achieved by adding together two 90.degree. all pass phase shifters. In addition, automatic tuning is provided by two feedback control loops; one is responsive to out-of-phase signals which controls the RC filter circuits of the phase shifters and the other responds to the in-phase signals which controls the output summing junction of the notch filter. Finally, a feedforward type of simultaneous tuning is accomplished by ganging the oscillator frequency adjustment with the analyzer.

Abstract: A control circuit for use with an amplifier is disclosed which includes an amplifier circuit having an input transistor, a driving transistor and an output transistor, a negative feedback circuit consisting of a parallel connection of a capacitor and a resistor and connected between the output terminal of the output transistor and the base of the driving transistor of the amplifier circuit. It also includes a transistor having its collector and emitter connected to the negative feedback circuit, a charging and discharging circuit connected to the base of the last mentioned transistor, and a voltage source connected to the charging and discharging circuit through a switch. The operation of the amplifier circuit is controlled by instantly making the switch on through the charging and discharging circuit and the transistor.