Abstract: A signal recording/reproducing apparatus having both bar-type and numeric signal-level displaying units which can be easily read. The apparatus includes a sample-and-hold circuit for sampling and holding an input signal at a first predetermined rate, a first display unit for displaying in bar form the sample values sampled by the sample-and-hold circuit, a data holding circuit for sampling and holding the sample values periodically at a second predetermined rate, and a second display unit for numerically displaying the sample values selected by the data holding circuit. The bar code display can change at a rapid rate to dynamically follow the input signal, while the numeric display changes at a slower rate so as to allow the user sufficient time to comprehend the numerically displayed value.

Abstract: A digital measuring method an apparatus for displaying quasi-analog measured values performs the steps of displaying a measurement scale and interconnected triggerable indicator segments on a display having a given indicator center distance, representing a measured value to be indicated by the position of the indicator segments, controlling the resolution of the quasi-analog measured value display in dependence of the number of indicator segments triggerable within a measurement period to be represented, setting the resolution substantially lower than a resolution with which an A/D converter connected to the display operates, and subjecting a control command for triggering an actual indicator segment to a hysteresis, which assures that a switchover from a previous indicator segment to an actual indicator segmet does not take place until the actual measured value has increased or decreased by substantially more than one-half the given indicator center distance.

Abstract: In order to display a measured value, a digital measuring instrument is provided with a digital display and an analog display. The display value emitted by the digital display is fixed during a predetermined holding time. The analog display displays the difference between the current measured value and the particular display value of the digital display at the time. The current measured value may be read off at the beginning of a new holding time on the digital display, or it can be ascertained as the sum of the values of the digital and analog displays.

Abstract: A digital measuring device for a quasi-analog measurement value indication includes a display for the measurement value indication, a pre-determined overall measuring range disposed on the display, a measurement value scale forming a spread measuring range section of the overall measuring range with variable spreading, the measuring value scale being addressable in planar segments with alpha numeric characters, an indicating device for indicating a value on the measuring value scale, and an automatic control placing measurement values within the displayed measuring range section with numerically displayed scale values fitting the measuring range section, with the overall measuring range remaining constant and the measuring range section having a selected spreading factor.

Abstract: A display signal generator device which allows the pulse width of a digital signal to be constant and the pulse repetition period to be proportional to the analog amount of an input signal so as to produce a signal to be displayed even by an analog or digital display unit 7 or 6, thereby obtaining a digital/analog common signal of average value proportional to the frequency even with the pulse signal. In order to maintain the pulse width constant, only a monostable multivibrator is, for example, added, thereby providing an inexpensive display signal generator device.

Abstract: Apparatus is provided for simultaneously measuring and displaying voltage, current and frequency in a polyphase alternating current system. The apparatus is operable in either a line-to-line or a line-to-neutral measuring mode without rewiring the apparatus to the measured system. A logic circuit is selectively operated to connect the appropriate voltage lines associated with each phase of the system to the apparatus and LEDs associated with each phase light to indicate the phase selected for measurement. Multi-digit seven segment LED displays are provided for simultaneously indicating the voltage, current and frequency measured.

Abstract: A stereo sound level display device includes a single array of light emitting diodes aligned in a line. The left channel sound signal level is detected to display the left channel sound signal level from the left end of the light emitting diode array. At the same time, the right channel sound signal level is detected to display the right channel sound signal level from the right end of the light emitting diode array.

Abstract: A dual loudness meter and method for simultaneously indicating the apparent loudness of composite audio program material representing peak material or of persistent material employing a first detector means responsive to peak signals for instantaneously indicating the same as a singly actuated LED indicator in an array thereof displayed in accordance with the peak strength of the signal, a second detector for detecting the persistence of the signal and displaying the same as a bar graph on said LED display, the materials being colinearlly displayed and having dual upper extreme warning/operating indicator means separated by about 12 to 14 dB so that the meter is read as requiring adjustment of the associated recording or broadcast facilities to avoid having either of said programming indicator displays reading consistently in either warning/operating zone. Specific circuits and time constants of response and decay are given as appropriate to the simultaneous reading, dual meter system disclosed.

Abstract: A multiple rate metering system suitable for use with an existing single rate, electromechanical electricity meter employing an Eddy current disc mounted in a casing, comprises a first unit mountable inside the casing of the electricity meter, and a second unit, which is portable so that it can be brought into close proximity with said first unit by a meter reader. The first unit comprises a sensor for generating pulses in response to rotation of the Eddy current disc, a first microprocessor, a first read-only-memory for storing a program to control the operation of said first microprocessor, a random-access-memory, the first microprocessor being programmed to store data in said random-access memory related to the pulse count in different predetermined periods during which different electricity rates apply, and a first coupling device for establishing communication through the casing with said second unit when said second unit is brought into proximity with said first unit.

Abstract: A modular backlighted analog/digital display for use in a cylindrical aircraft instrument housing. The analog indicator dial is backlighted by an illumination source diffused by a translucent light collecting plate having a configuration corresponding to that of the analog dial. A polarizing filter is mounted in an opening formed in a portion of the light collecting plate to enhance image contrast of the digits of a digital display of the self-illuminated type, e.g. an incandescent or LED digital readout, that is exposed through a cutout portion formed in the analog dial. In addition, the interior of the opening in which the display is received can be coated with a light opaque material to prevent light scattered from the light collecting plate from reaching the face of the digital display and washing out the digits. The analog pointer is formed from a translucent material and is connected to an analog meter mechanism.

Abstract: An electrical indicator device for providing simultaneous relatively coarse analog, and higher-resolution, digital readings of a particular electrical parameter, all in one instrument. The device includes either a d'Arsonval meter movement or a servo-motor or other motivated electro-responsive device which carries a pointer movable over a predetermined portion of a calibrated meter scale plate, and a liquid crystal display having multiple digits, each digit being constituted of multiple segments. The segments are disposed completely within the confines of the meter scale plate, but lie substantially completely outside of the said predetermined portion thereof. The display is driven or energized by a digital voltmeter having its terminals connected to receive and monitor the same parameter that is being measured by the motivated electro-responsive device.

Abstract: A modular analog/digital display for use in a cylindrical aircraft instrument housing is designed to enable the digital components to be assembled without interference to the analog meter mechanism. The digital display is of the leadless type and is clamped under compression to a circular circuit board with a pair of contact strips in registration with contacts formed on the circuit board and digital display. The design also features a screw-on dial pointer which facilitates the assembly of the digital display components and dial to the analog meter mechanism without interference.

Abstract: An electrical indicator device for providing simultaneous relatively coarse analog, and higher-resolution, digital readings of a particular electrical parameter, all in one instrument. The device includes a d'Arsonval meter movement which carries a pointer movable over a predetermined portion of a calibrated meter scale plate, and a liquid crystal display having multiple digits, each digit being constituted of multiple segments. The segments are disposed completely within the confines of the meter scale plate, but lie substantially completely outside of the said predetermined portion thereof. The display is driven or energized by a digital voltmeter having its terminals connected to receive and monitor the same parameter that is being measured by the d'Arsonval movement. The arrangement is such that the individual segments of the digital display are always completely visible regardless of the position which the pointer occupies with respect to the said predetermined portion of the scale plate.

Abstract: An improved multi-channel galvanometer assembly is disclosed particularly well adapted for use in such instruments as electroencephalographs and the like. The assembly includes a soft steel combination return path structure and frame supporting a plurality of galvanometer movements. The design employs pairs of samarium cobalt magnets held in place adjacent and on opposite sides of the coil of each galvanometer by magnetic attraction to the steel return path structure. The galvanometers themselves are each mounted on an aluminum support plate which also serves as a shield to prevent magnetic coupling between adjacent galvanometer coils when the galvanometers are assembled in the support frame. The galvanometers on their support plates are each individually removable and/or replaceable. The result is a lighter, smaller, multi-channel galvanometer assembly which is readily expandable and easily serviced.

Abstract: A readout device connected to a parent metering system contains a digital display for circumventing the non-linearity of analog meter movement in the parent system. The readout device displays both numerical and dimensional information in a clear, legible form with both probe and range scale factors accounted for in the display itself. A "probe" switch on the front panel of the module encodes the logarithm of the scale factor associated with the probe in use to a two's complement binary number, and the full scale range information from the "range" switch is encoded in the same manner. This information, along with function information from the "function" switch, is processed by a scale computation circuit which positions the decimal point and causes the units of measurement to be indicated accordingly.

Abstract: A vector voltmeter for measuring the amplitude and phase difference between two signals. A first signal is fed to a power divider in which one of its outputs is measured with a power detector and the other output is fed to a second divider, each output thereof being fed one each to a third and fourth power divider. The second signal is fed to a fifth power divider in which one of its outputs is measured by a second power detector and the other output of the fifth divider is fed to a hybrid circuit having quadrature outputs, one of which is fed to the third power divider whose output is measured by a third power detector and the other quadrature output is fed to the fourth power divider whose output is measured by a fourth power detector. The four power detectors are connected to two differential amplifiers which drive the X and Y axis of an oscilloscope.