A Darlington difference amplifier in which the offset voltage, produced by the difference between the current amplification factors of the output transistors, is reduced by such a feedback that substantially no signal voltage appears across the base-emitter junctions of the input transistors.

A Darlington difference amplifier including two pairs of transistors in which the offset voltage is reduced by applying a compensation voltage to the input or to the output of the amplifier. This voltage contains, in a compensating sense, the error voltage caused by any difference between the current amplification factors of the output transistors. The compensation voltage is obtained by reproducing the base-emitter voltages of the input transistors of the amplifier in the PN junctions of one or...

An altitude difference measuring apparatus for measuring the difference between the altitudes at a first and second points on the basis of the barometric difference between the points, having an air pressure holding section with an electromagnetic valve for hermetrically containing an amount of air. At the first place an amount of the ambient air is held hermetrically in the air pressure holding section, and at the second place the barometric difference between the air pressure in the air pressu...

Apparatus is described for eliminating monochromatic interfering frequency components of seismic signals detected during the course of seismic exploration comprising an electrical circuit for producing a monochromatic nulling signal that has the same frequency as the interfering signal. The monochromatic nulling signal is produced by generating a truncated triangular wave having the same period as the interfering signal and filtering the truncated triangular wave to remove all components thereof...

There is provided a pair of flip-flops, each of which is set before appearance of every one of two input signals to be compared. One of the input signals is applied to a reset terminal of the first flip-flop through an inverter, and the other input signal to that of the second flip-flop through another inverter. There is further provided a pair of AND gates. A set output of the first flip-flop is led to one of two input terminals of the first AND gate through a delay element, and a reset output ...

A differential current sense amplifier is shown suitable for high speed semiconductor memory sensing. A reference current generation circuit is also developed for operating a plurality of sense amplifiers.

A pressure differential measuring apparatus comprising a cylindrical member having a first portion and a second portion of reduced diameter relative to the first portion. The first portion is provided with an outwardly extending member, while the second portion serves as a control rod. The instrument is further provided with a resilient bendable tubular member which surrounds the second portion and is connected to the outwardly extending member of the first portion by a circular electron-beam-we...

A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the u...

An aerogenerator comprises a structure, a vertical rotary shaft support by the structure, an electrical power generating device directly or indirectly connected to the rotary shaft, annularly arranged floating chimneys rotatable together with the rotary shaft therearound, and blades fixed to each of the chimneys and extending radially of the rotary shaft.

A phase difference autofocus method that only requires one FFT for estimating a phase error in the entire synthetic array radar data. The phase difference autofocus method of the present invention automatically and efficiently estimates phase errors from radar signals, allowing a well focused SAR image to be produced. The present method comprises the following steps. First, each range bin is divided into two subarrays. Next, the two subarrays are complex-conjugate multiplied together to produce ...