Abstract: A meter cover (housing) mounted mechanism incorporating a combination key operated tamper resistant security lock, externally controllable meter reset actuator and meter access hatch.

Abstract: A detector apparatus for counterfeit paper currency comprising a clamp and torsion pendulum assembly for holding a note to be tested, a moveable magnetic field source mounted so that it can be brought into contact with the note and then withdrawn, and indicating means for detecting and measuring deflection of the note.

Abstract: A circuit for ascertaining the direction of origin of the most significant transient appearing on a electrical power line within a predetermined interval is disclosed. Threshhold comparator circuit (325, 326) are provided to insure that transient polarities needed for the directivity determination are ascertained while the transient impulse is still rising towards its peak value. For any nominal, user-set threshhold (V.sub.2), a lower preliminary threshold (V.sub.1) is automatically set and when the transient exceeds the preliminary threshhold, the transient polarities are determined and correlated to effect a tentative directivity determination which is stored in an input latch (205). When the transient exceeds the nominal threshhold, the directivity determination is transferred to an output latch (211) to be read by an output printing device.

Abstract: A revolution speed indicator arrangement is provided which includes a reference frequency oscillator, a tachogenerator for generating a frequency associated with a revolutional speed of the revolving body, difference frequency deriving circuitry interconnected to the reference frequency oscillator and the tachogenerator for deriving a difference frequency between the frequency associated with the revolutional speed and the reference frequency, and an indicator unit responsive to the difference frequency deriving circuitry for visually indicating the difference frequency. The arrangement may be provided with a coincidence determining unit responsive to the difference frequency for detecting coincidence between the frequency associated with the revolutional speed and the reference frequency, and the indicator unit is connected to the coincidence detecting unit to visually indicate the coincidence.

Abstract: A method of counting the number of load current pulsations in an alternating current supply including monitoring the alternations of the supply current and detecting pulsations thereof by detecting suitable falls of the pulsations following the rises thereof, creating upon detecting a pulsation a discrete signal therefor, said signal creation being powered from said pulsation, and counting the discrete signals to determine the number of pulsations.

Abstract: A light fastness and weather resistance testing apparatus which has a testing tank, a hollow shaft rotatably mounted in the center of the testing tank, a sample frame mounted on the hollow shaft and extending beyond one end of said hollow shaft, a motor connected to the shaft for rotating the shaft, a tube of electrically conductive metal extending through the hollow shaft and having one end at the space within the sample frame and a supply of cooling liquid connected to the other end of the tube for supplying a cooling liquid to the tube. A xenon lamp is in the space within the sample frame and has a cooling device mounted thereon constituted by a single wall cylindrical tube of an ultraviolet transmissive glass around the lamp and spaced therefrom, the low voltage end of the lamp being mounted on the one end of the metal tube and having the low voltage terminal thereof electrically connected to the metal tube, the other end of the glass tube having a drainage tube connected thereto.

Abstract: A current sensing transducer includes a conductive current divider including a branch path for conducting a fractional current proportional to a current to be sensed and being applied through the divider. A compensated transformer includes a primary circuit responsive to the fractional current and two secondary windings. An amplifier circuit controls the current input to one secondary winding in response to the output of the other secondary winding so that the flux of the primary circuit is virtually compensated in the core and the secondary winding current is a measure of the current to be sensed.

Abstract: A level indicating apparatus indicates the peak level of an analog signal and also indicates the instantaneous value of the analog signal during a recurring time interval of predetermined length. The apparatus includes a circuit for generating, during each recurring time interval, a train of pulses whose number corresponds to the level of the analog signal, a storage device which may be a shift register for storing the train of pulses, a circuit for forming a pulse whose position corresponds to the peak level of the analog signal, a feedback circuit for feeding the pulse, whose position corresponds to the peak level, back to the storage device to be combined with the train of pulses corresponding to the instantaneous value of the analog signal, and a display for indicating the peak value. Preferably the display also indicates the instantaneous value of the analog signal. The circuit for forming the pulse whose position corresponds to the peak value can include a logic differentiation circuit.

Abstract: The suspension of movable system instruments, for example, a galvanometer, introduces elastic reset torques upon deflection. To compensate for such torques and render the apparatus essentially independent of the deflection torques, an opto-electronic device provides an output signal representative of the deflection which is combined with the deflection voltage applied to the galvanometer to at least in part compensate for the reset torque introduced by the moving system suspension.

Abstract: This invention concerns gas filled thyratrons and is concerned with preventing the formation of arc spots on the grid when the thyratron is operated in a grounded grid mode. The thyratron provided has a grid consisting of three apertured baffle electrodes which are electrically united and occur in sequence in the cathode to anode path of the thyratron. The baffle electrodes on the cathode side of the final baffle electrode forms at least one re-entrant hollow cathode and conductive gauze covered apertures in the baffle electrodes on the cathode side of the final baffle electrode are staggered relative to apertures in the final baffle electrode.

Abstract: Improved mode-locked optical parametric oscillator apparatus comprises a mode-locked pump laser having a cavity with a predetermined effective length l.sub.p and a parametric oscillator having a nonlinear crystal, such as lithium niobate (LiNbO.sub.3), and singly resonant mirrors spaced apart by an effective distance l.sub.o which is substantially less than l.sub.p, i.e., l.sub.p .apprxeq.nl.sub.o where n.apprxeq.5-50. The interaction of the mode-locked pump output with the nonlinear crystal produces parametric outputs at signal (f.sub.s) and idler (f.sub.i) frequencies, the parametric oscillator mirrors being singly resonant at one of those two frequencies. The parametric oscillator may be disposed either externally of or within the pump cavity and the pump laser optionally may be Q-switched.

Abstract: The invention relates to an insulated-gate field effect transistor which is adapted for detecting and measuring various chemical properties such as ion activity in a solution. The device has a chemically sensitive layer which overlies a portion of a substrate other than that covered by the gate insulator. When this chemically sensitive layer is exposed to a solution or other substance, the electric field in the substrate is modified which changes the conductance of the channel between a source region and a drain region. The change in conductance is related to the chemical exposure and can be detected with a current meter.

Abstract: A method of producing low-pressure gas discharge lamps wherein filamenting wool is prepared into a mat and then brought into the discharge space.

Abstract: The accuracy and linearity of a moving-coil instrument is determined by the choice of materials, the design and the production tolerances.The invention proposes to make an inaccurate moving-coil meter with a non-linear relationship between meter current and meter deflection accurate and to provide it with a linear scale by adding a diode-resistor network and adjusting said network so that said accurate linear scale is obtained. Direct current or direct voltage inputs are then possible. An inexpensive accurate, analog indicating instrument is then obtained which may be used in a variety of measuring systems.

Abstract: In a power system, a time-of-day demand meter of the type having a programmable control circuit for generating a control signal at prescribed intervals to enable a demand logic circuit to control the engagement of a demand register of the meter includes apparatus responsive to the control signal to generate an end of interval signal to disengage the demand register at a specified time as selected by the apparatus to control the length of demand intervals during which the consumption of electrical energy is measured.

Abstract: All of the pairs of insulated telephone lines in a long line cable are spliced at the same intervals and the splices are situated in junction boxes where linemen can have access to both junctions of each pair. Each line splice consists of a metallic splice bar forced into electrical contact with each of the parallel, spaced-apart ends of the line, the splice bar and both line ends being encased in a splice body of plastic, dielectric material which is provided with an access opening through to the splice bar between the spaced apart lines. A continuity check probe of the invention includes a metallic hook-shape rod having a short finger of shape and dimension to pass through the body access opening to contact the splice bar when a parallel, spaced-apart long finger of the rod lies in parallel, adjacent relation to the splice body.

Abstract: An automobile alternator test apparatus tests for the presence of a failed diode by detecting a frequency component (a subharmonic component) in the alternator output ripple voltage produced by the failed diode. The subharmonic frequency component is detected by a tracking filter that is slaved to the subharmonic frequency of the ripple frequency voltage produced by the failed diode. The output signal of the slaved filter indicates the presence of the failed diode.

Abstract: A high speed, wide angular aperture, spectrally selective optical gate is achieved by using degenerate four-wave mixing. The apparatus utilizes two counterpropagating pump beams to interact with a probe beam through a third order nonlinearity in the susceptibility of a medium to produce an image beam which is counterdirectional to the probe beam. The image beam is produced only during the time that the two pump beams and the probe beam are coincident in time and space in media having a fast nonlinearity. In slow media, fast gating is achieved by turning off both pump beams after the probe beam and the pump beams have interacted. This apparatus produces gate times which are not limited by the speed of relaxation of the nonlinearity in the medium utilized.

Abstract: A bridge circuit for measuring or use in a temperature-responsive servo-mechanism. A chain of four or alternatively five resistors is connected between power supply rails, an inner two resistors of the chain being shunted by the track of a potentiometer. A balancing potentiometer is connected directly across the supply rails and has its wiper connected to one side of a balance detector through a high value resistor. The signal to be measured is applied between the chain of resistors and the other side of the balance detector. There is a resistive connection from the wiper of the first-mentioned potentiometer and the resistor chain to the end of the high value resistor nearer the detector. The signal to be measured is derived from a resistance-type or thermo-couple temperature sensor. Reference junction compensation for the latter is described.

Abstract: A method and means for suppressing ozone generated by high pressure xenon arc lamps and similar luminous discharge arc lamps of a type normally generating ozone. The ozone-generating lamp is enclosed in a gas-tight housing having a quartz or sapphire light emission window able to transmit light including ultraviolet. The housing has metal cover plates on its various sides acting as heat sinks, each of which has a large number of external heat-radiating fins. Clearance is provided inside the housing sufficient to cause the ozone formed by short wavelengths to be broken down by thermal contact with the lamp and to be thus converted into stable O.sub.2. The heat generated by the lamp in the housing is transferred to the walls of the housing and is dissipated by the external heat-radiating fins. The inner surfaces of the cover plates are blackened to absorb waste light.