Abstract: An improved system for driving a gas discharge display which prevents streamers of ionized gas from forming between adjacent character positions. Each of a plurality of character positions has an anode driver to which anode drive signals are sequentially applied. All odd character positions share a first cathode decoder/driver and all even character positions share a second cathode decoder/driver. Cathode drive signals are simultaneously applied to the first and second decoder/driver circuits. A first logic device, responsive to all odd position anode drive signals, outputs a blanking signal which is applied to the blanking input of the even character cathode decoder/driver to bias all even character cathodes into a non-conducting state whenever an anode drive signal is applied to an odd character anode.

Abstract: An offset circuit for use in providing an offset signal to an analog-to-digital converter. The analog-to-digital converter has an integrator for performing signal integrate operations and is connected to a digital display. The offset circuit is gated to provide a variable offset current directly to the integrator of the analog-to-digital converter, thereby eliminating adverse loading effects on the high input impedance of the analog-to-digital converter.

Abstract: A waveform to be analyzed is repetitively sampled at corresponding instants in each of several cycles, and the samples from each cycle for a respective instant summed to derive an average value for that instant in one cycle of the waveform. The average values are then used for Fourier transform analysis, either by mathematical manipulation or by sequential correlation. The timing of the samples is determined by counting pulses from a high-frequency clock for one cycle of the waveform, truncating the count to remove the n least significant digits, and taking a sample every time a number of pulses equal to the truncated count has occurred (resulting in 2.sup.n samples per cycle for a modulo 2 counter).

Abstract: A thermal actuator or heat motor employing end-to-end bimetal, bistable strip portions spanning a pair of supports but having a total length greater than the straight-line distance across the supports and capable, upon the selective application of heat to either portion to the exclusion of the other to cause the strip portions to snap back and forth across a centerline representing the straight-line distance across the supports, together with selective heat-applying means and a force-transmitting element connected to the midpoint of the strip portions for supplying mechanical, electro-mechanical, etc., power.

Abstract: A capacitor which includes a case containing a capacitor element with a pair of unequal length overlapping tabs extending therefrom. A header for sealing the case carries a pair of leads. Each tab is welded to one of the leads with an insulator interposed between the tabs.

Abstract: A voltage offset circuit for use with an amplifier connected to receive low voltage signal inputs and operable for eliminating internal voltage offset errors of the amplifier as well as systemic voltage offsets. A variable voltage generating means is utilized to impress a voltage on an output capacitor of the amplifier which is operable in an auto-zero and measuring mode of operation. Preferably, the offset circuit and amplifier are utilized with digital meters employing an analog-to-digital converter having an auto-zero phase and measuring phase of operation.

Abstract: A magnetic system for a long scale electrical meter enables four sided sensing of a coil which is completely offset from the axis of rotation has a cylindrical core pole piece magnetically coupled to first similar poles of two magnets. The core is surrounded by an inner annular air gap defined by a coaxial inner annular pole piece which is magnetically coupled to the second poles of the magnets. Radially outward is an outer annular air gap defined by a coaxial outer annular pole piece which is magnetically coupled to the first magnetic pole. Magnetic fields in the inner and outer air gaps are radial. The outer annular pole piece is closed at opposite ends by a pair of magnetically permeable discs which also are pole pieces for the first magnetic pole. Each disc is spaced apart a distance D from the nearest flat face of the inner annular pole piece to provide axial magnetic fields. Accordingly, all four sides of the coil are active.

Abstract: The variable attenuator and variable current shunt of a battery-powered auto-ranging digital multimeter uses latching relays, each of which, since it is stable in each of its two switching states, requires only a current pulse to change its state. The circuit which operates the relays provides a drive pulse only when the desired relay state differs from the actual state, thus minimizing the power required, and includes a tank circuit for minimizing disturbance to the multimeter power supply. To ensure that the tank circuit can recharge, each relay is driven by a tri-state output.

Abstract: A vibrating fluid density transducer 10 provides a gas density measurement D, used in conjunction with a flowmeter signal f.sub.B to meter the mass of gas fed through a pipeline. D is subject to errors dependent upon the velocity of sound C in the gas. The errors are corrected to yield Da by application of a correcting formula (block 18) in which C is introduced by calculation (block 17) from a measurement of gas pressure P by a transducer P. The value of C may alternatively be measured directly, computed from a measurement of specific gravity or in the case of a liquid, be inferred from D or be preset.

Abstract: The effects of any errors in the preliminary tracking of a target, and of any subsequent changes in the velocity of the target, are included in simulated firing of a gun 3, by slewing a laser projector 2 in the simulator for the predicted shell time-of-flight at the rate assessed during the preliminary tracking and then scanning with the laser for hit/miss determination. The slewing is achieved either by having the gun control system slew at the required rate, or by having the gunner continue tracking the target, corrections for deviations from the required rate being automatically applied to the projector.

Abstract: Directional relay and method for monitoring at least one A.C. power transmission line to determine the position of a fault on the line with respect to a measurement location thereon.According to a representative embodiment characteristic parameters, typically the respective phases, of a first signal representing the difference of complex voltages after and before the occurrence of the fault and of a second signal representing the line current after the occurrence of the fault, are compared, the result of the comparison providing the desired indication.

Abstract: A single patch on an integrated circuit is arranged to patch any one of four different logical states into the circuit, according to whether the pin is grounded, floating, coupled to a supply rail via a resistor, or coupled to the supply rail directly. In one embodiment, the voltage thresholds of three transistors are arranged so that they switch on successively in response to successively higher voltages on the patch pin, thereby controlling the binary logic signals at each of two output points in the circuit; in the other embodiment, multi-emitter transistors are arranged with differing current thresholds to achieve the same result.

Abstract: For initial alignment of a simulator laser-projector with a weapon, the weapon is boresighted on a target, the projector is fitted and the laser beam is scanned stepwise across the target successively along orthogonal axes. The range of steps on each axis for which a return from the target occurs is sensed, and the step corresponding to the median of all the returns taken as the position for which the laser beam is centered on the target. These calculated positions are stored and used as the reference positions during simulated firing of the weapon. The detection of the position of a target for hit/miss determination is achieved with the same scanning and median selection procedure.

Abstract: A differential pressure transducer, primarily for measuring gauge pressure, comprises first and second identical, substantially cylindrical, sealed capsule assemblies, each having a circular diaphragm at one axial end. The capsule assemblies are welded into the opposite ends of a cylindrical housing, with the diaphragms facing outwardly. The housing is designed to permit the transducer to be mounted in the wall of a pipe or chamber, with the diaphragm of one capsule subjected to the fluid pressure in the pipe or chamber and the diaphragm of the other capsule subjected to ambient atmospheric pressure. Respective inductive displacement sensors produce respective signals indicative of diaphragm displacement. The use of sealed capsules ensures that if a diaphragm ruptures, fluid loss cannot occur.

Abstract: The temperature of the condensation point of light hydrocarbons in a gas is quickly determined by heating a frosted mirror placed in a gas swept enclosure up to the evaporation temperature of all the heavy and light hydrocarbons. The mirror is first cooled as quickly as possible to a temperature higher than the presumed condensation temperature for the light hydrocarbons. Then is cooled much more slowly until the appearance of the first condensations on the mirror. Another cycle as described above is started, in which the presumed condensation temperature value is taken as being equal to the condensation start temperature value of the previous cycle.

Abstract: A radio control system for controlling model airplanes, model boats and the like. The system includes a multi-channel transmitter and a multi-channel receiver each operative on the same assigned radio control frequency. The system operating frequency is changeable by exchanging both a small pluggable transmitter module and a small pluggable receiver module with a different transmitter and receiver module respectively, the latter modules being operative on an assigned radio control frequency different from that of the former modules. The system provides quick and easy change of the operating frequency thereby permitting simultaneous radio control of many models via many such systems operating on non-interfering radio control frequencies.

Abstract: An AC display excitation and synchronous display updating circuit for a digital electronic instrument in which the counter accumulating clock pulses representative of the magnitude of the quantity to be represented on the digital display is used as a frequency divider to obtain an AC display energizing signal whose frequency is reduced from the clock frequency to a suitable level for energizing the display. The contents of the continuously driven counter are synchronously transferred to the display register at the end of the conversion cycle by the use of a two-phase clock.

Abstract: A circuit for protecting speakers connected to the output of an audio amplifier. The output of the amplifier is connected to a filter which blocks normal audio frequency signals but passes both high and low frequency signals outside the normal audio range. The positive and negative filter output signals are connected respectively to the inverting and non-inverting inputs of an operational amplifier whose output is connected via a turn-on delay circuit to a speaker relay, which, when closed, connects the speaker to the amplifier. The turn-on delay circuit prevents speaker relay closure until turn-on transients have ended. If a DC voltage or a high frequency signal is present at the amplifier output, the operational amplifier generates a signal to open the relay thereby disconnecting the speaker from the amplifier output. The speaker relay quickly opens when power is turned off so that amplifier turn-off transients are not connected to the speaker either.