A fault on a telephone cable pair which may contain other impedance irregularities is located by a frequency-domain distance detection system. The difference between the input impedance of the circuit which contains the fault and a standard impedance is measured periodically across a set of predetermined frequency bands to produce a corresponding set of periodic time functions. The power spectra of these functions are determined, and the frequencies of the spectra mamima are used to estimate the...

A transit system having an array of closed loop transportation paths with no intersecting or switching points. The loop array include major or express loops between distant terminals and minor or local loops for short distance travel between interurban terminals. The system involves passengers switching from one terminal to another rather than vehicle switching.

A digital detecting system for creating an output signal when an electrically conductive object, such as a vehicle, comes within the field of effect of a loop. The system includes means for creating a pulse train having a frequency controlled primarily by the inductance of the loop, means for counting the pulses of the pulse train for a selected time interval to produce a count generally representative of the inductance of the loop during the time interval, means for creating a reference count, ...

A back-fire loop antenna having a loop of one or more turns situated between a pair of reflectors parallel with the plane of the loop, one reflector being larger than the other, there being means for supporting the loop and the reflectors in the required positions.

The invention is a multiturn loop antenna of an efficient design suitable for use singly, in arrays, or for inductively exciting radiating currents on a structure -- the surface and the elements radiating to achieve optimum system performance. The antenna may be fed balanced or unbalanced and its input impedance may be either capacitive or inductive. In a preferred embodiment for omnidirectional coverage the antenna is positioned in a dielectric or ferrite filled cavity; the antenna may be a sin...

A phase-locked loop comprises a crystal voltage controlled oscillator for generating an output signal having a frequency related to an input signal, a phase detector for selectively combining an incoming signal and the output signal of the crystal voltage controlled oscillator and for generating an output signal which contains the sum and difference frequencies of the combined signals, and a low pass filter for filtering out the sum frequency signal. The difference frequency signal at an output ...

There is disclosed a solid state differential loop current detector to detect and measure current unbalance in a two wire telephone cable connected in a direct current loop configuration wherein the current unbalance is due to paths to ground potential from the telephone cable. The detector includes a first solid state operational amplifier appropriately connected to an input terminal supplying a voltage to the adjacent end of one wire of the telephone cable and to the adjacent end of the one wi...

An apparatus and a process for producing generated gas wherein the generated gas is cooled and then a portion recirculated into the generated gas as it leaves the generator. Such serves to rapidly cool the generated gas so as to inhibit or prevent formation of solid carbon particles and preventing change of chemical analysis.

The invention provides a mechanism for transporting photographic film past an aperture in a projector, camera or other motion picture machine, and more particularly to a rolling loop film transport mechanism which transports film between a rotor and a stator for placing frame lengths of the film against an aperture in the stator such that each frame length then has substantially the same curvature as the aperture independently of the curvature of the stator.

A digital loop tracks the frequency and phase of an incoming signal, such as, but limited to an incoming phase encoded signal, to generate a tracking frequency signal. Zero crossings of the incoming signal are converted into trigger pulses for activating and terminating an up/down counter. The counter advances up from a reference level to a count stored in an average count storage register and then reverses direction and counts down to the initial reference. The counter cycle continues until a z...