A dynamic radiography system for examining an optically opaque object containing radiation scattering centers by irradiating the object with penetrating radiation to cause radiation scattering by these scattering centers, causing periodic vibration of these scattering centers, detecting radiation scattered by the scattering centers in the object along at least two noncongruent detection channels which are at an angle with each other and which intersect at a common volume within the object, and c...

In a full wave rectified control circuit for a D-C motor comprising two banks of silicon controlled rectifiers for forward and reverse operation, there is provided a pulse generation system which applies a firing signal to each of the control SCR's when the power to the motor is lost. A short circuit is thereby provided for the motor armature through the control circuit and the rotational energy of the motor is rapidly dissipated to effect dynamic braking.

The disclosure describes a system for automatically controlling the time constant of an electronic filter to significantly alter the transition time from one signal response level to another. The system employs a variable impedance means, such as a field effect transistor, which can alter the effective time constant of the filter. Sensor means sample the imput signal to the filter and produce a control signal in response to an amount and rate of change in the input signal greater than a predeter...

A dynamic analyzer for evaluation of voltage-current related properties in an external system and, in a particular application, to a unique potentiostat employed in performing electrochemical analysis of corrosion phenomena in a test cell. The dyanamic analyzer has an isolation amplifier to sense electrode potential in the test cell with an output in a voltage loop including a triangular wave voltage sweep generator, an offset voltage source and a voltage comparator (error signal amplifier). The...

A dynamic stop for an operator-less railway transportation system consisting of an arm positioned between the tracks of the transportation system and pivotably mounted so that it does not interfere with the passage of the cars of the railway transportation system when not in use, but may be rotated up so that an absorbent stop plate mounted thereon will contact an absorbent bumper mounted on the front of the car which it is desired to stop. The dynamic stop may be mounted on a reciprocating devi...

A dynamic modulator for modulating fluid pressure transients in the hydraulic lines to a hydraulically actuated device, the modulator including a metering piston to control the flow of fluid bypassed through the modulator; a modulating piston positioned to respond to the movement of the metering piston and to control the response of the metering piston; and a bypass duct network connected across the metering piston and including metering valves to control the time interval of response of the met...

A dynamic microphone in which vibrations transmitted to the case of the microphone are cancelled over a very wide frequency range. A moving coil type microphone unit sensitive to sound and a moving coil type vibration pickup unit sensitive to vibrations transmitted to the case of the microphone are provided in the case with a common magnetic circuit. The outputs of the moving coil vibration unit are coupled to the outputs of the microphone unit in opposite phase so that noise components correspo...

A plurality of nodes of split vibration of a diaphragm are driven by a plurality of voice coils to prevent split vibration of the diaphragm. The voice coils are inserted between three or more layers of magnetic poles respectively and driven by a magnetic circuit including a plurality of magnets magnetized in the same direction as the vibration of the voice coils.

A dynamic transformer comprises input terminals for supplying an alternating-current control signal and an alternating current slotted-ring stator having two nondistributed exciting windings each of which comprises two equal diametrically opposed sections. Each winding section embraces a predetermined sector of the stator ring and the winding sections are equally spaced about the stator 360.degree./2n .+-. 1/2 of the sector. The windings are excited in phase from input terminals. The transformer...

A semiconductor memory is provided with a first memory cell group, a second memory cell group, a first register for a serial output operation for holding information related to the first memory cell group, a second register for a serial output operation for holding information related to the second memory cell group, and transfer means for transferring information related to either the first or second memory cell group to either the first or second serial output register. By virtue of this arran...