A device for providing an orderly shut-down of a system of interconnected traffic lights upon loss of its primary electrical power is disclosed. A device for permitting consistent reapplication of power to a line conditioner having a ferroresonant transformer is also disclosed. Further, a battery charger for charging a battery system including a plurality of battery cells coupled in series is disclosed. Additionally, a device for determining proper operation of a power transistor by monitoring i...

Apparatus for immobilization of infant patients during exposure of X-ray film, particularly in connection with studies requiring the so-called frog-leg position. Use of this invention permits considerable reduction in the extent of exposure of the patient's body, and eliminates the need of manual restraint of extremities and exposure of a non-patient to radiation. Moreover, the required size of film is much reduced. In a preferred embodiment antero-posterior projections of a patient in both stra...

A periodic signal to be detected plus associated noise components are ampied, filtered and applied as an input to a pair of chopper switches gated synchronously with the signal to switchably chop the signal into phase-locked, complementary half wave portions. In effect, each of the chopper outputs has a direct current waveform with one of the outputs being opposite in sign to the other. The chopper outputs then are applied as separate inputs to the inverting and non-inverting inputs of a differe...

A gating system for use with a frequency discriminator which will provide a positive indication of whether or not two input signals are the same frequency or, if they are not the same frequency, which one is the higher. The apparatus is for use with a frequency detector providing logic "1" and logic "0" outputs indicative of the highest frequency and providing an alternating output when the two frequencies are identical. The output of the frequency discriminator is utilized to steer flip-flops t...

A variable frequency three-phase square wave signal is synchronized to a three-phase reference frequency signal at a substantially zero degree phase relation. Synchronization is accomplished in but a few cycles by comparing each component of the two signals to be compared and also comparing both positive and negative going half cycles of each component. Six phase error magnitude pulses are generated for each cycle and identified according to phase error sense to provide an output error signal ha...

The subject disclosure relates to novel and improved apparatus for detecting and nulling the difference in phase between a pair of electrical operational channels. The apparatus includes a signal generator which applies a test signal to each operational channel, a phase detector coupled to the output of the channels, an analog to digital converter that converts the detected phase difference into a count in and up and down counter circuit and switching devices that in response to the output of th...

In the medical treatment and examination of animate patients, means to flex and secure a spinal column against movement, exclusive of applying pressure to the head and/or neck, comprising coactively adjustable seat and shoulder engaging elements, arranged to flex the spinal column in an optimum posture of flexure, while simultaneously restraining the patient against movement of his spinal column. Coactive plates engaging patient's shoulders and the seat under and around the pelvis are compressed...

A transducer comprising an acoustic energy generating means and a resonator. The acoustic energy generating means generates acoustic energy and is adapted for delivering an approximately uniform amount of acoustic energy to each unit of surface area on a substrate in a given time period when the substrate is rotating. The acoustic energy generating means has a surface area that is less than the surface area of the substrate, and may comprise a wedge shaped piezoelectric crystal. A resonator is a...

A method of measuring a desired frequency by comparing it with a standard frequency. The zero crossings of both frequencies are detected. A command pulse is generated at each coincidence and is used to start and stop a pair of frequency counters adapted to count the desired and standard frequencies. A measure of the desired frequency is obtained by multiplying the known standard frequency by the ratio between the desired count and the standard count obtained in the two frequency counters.

A signal to be discriminated of frequency f.sub.1 and a reference signal of frequency f.sub.2 are applied to a mixer which outputs two quadrature phase related, reversible beat frequency signals e.sub.a and e.sub.b, in accordance with the frequency conditions of f.sub.1 < f.sub.2 or f.sub.1 > f.sub.2. The signals e.sub.a and e.sub.b are coded into two level signals as to their respective levels. A phase discrimination circuit receives the signals e.sub.a and e.sub.b and outputs an AC signa...