Abstract: Circuitry for generating a sine wave and/or a cosine wave from a pulse signal wherein cyclically repeating pulses each generate one cycle of a sine wave and/or a cosine wave. Each pulse institutes a sawtooth signal; a square wave generator produces a square wave having a positive excursion for one-half of the sawtooth signal and a negative excursion for the other half of the sawtooth signal. The square wave signal is integrated to produce a triangular wave. The triangular wave may be shaped into a simulated harmonic wave by wave-shaping circuitry. If both sine and cosine waves are desired, additional circuitry is employed to convert the described square wave to another square wave of the same frequency, 90.degree. out of phase with the first square wave. The other square wave is converted to a corresponding triangular wave which is shaped to a simulated harmonic wave by wave-shaping circuitry.

Abstract: A pulse signal conditioning circuit. Repetitive pulse signals can be sharpened and freed of accompanying, unwanted noise manifestations by means of a network of steering diodes and constant current diodes feeding a comparator circuit producing sharp, uniform pulses.

Abstract: An electromechanical transducer employs an Eddy current type displacement sensing device mounted in confronting relation to a seismically supported, nonmagnetic metal beam which is presented within an enclosed chamber. Movement of the nonmagnetic metal beam is damped. Movement of the nonmagnetic metal beam relative to the Eddy current type displacement sensing device occurs when the device is moving cyclically at low frequencies up to about 200 Hertz. Because of the damping of the movement of the metal beam, its instantaneous displacement is proportional to the instantaneous acceleration applied to the transducer. The output electrical signal from the Eddy current displacement sensing device can be integrated to provide an output signal directly proportional to the instantaneous velocity of the transducer. The signal can be twice integrated to provide an output signal corresponding to the instantaneous displacement of the transducer.

Abstract: An intrinsic safety barrier for use in combination with electromagnetic transducers which are intended to generate alternating current signals in hazardous zones and to transmit such alternating signals out of the hazardous zone to remote signal-responsive installations. The intrinsic safety barrier permits transmission of alternating current signals without significant distortion and yet precludes introduction of surges of electrical energy into the hazardous area.

Abstract: A combination electronic device provides balance analyzing capabilities, narrow band and wide band spectrum analysis capabilities, automatic tracking filtering capabilities, precision dynamic balancing with remote phase presentation, and tracking filtering. The device presents multiple functions including:1. A testing function;2. A balancing function;3. A tracking filter function;4. A filter-out-speed function;5. A filter-out-frequency function;6. Spectrum analysis function.Included within the circuitry are the following components:A. a vibration signal conditioning circuit;B. an active filter having the equivalent of a four-pole response with a two-pole delay;C. a pulse-to-sine and pulse-to-consine reference signal generating circuit;D. a reference pulse conditioning circuit;E. a digital sweep circuit for spectrum analysis;F. switching circuitry to accommodate all six functions;G. adjustment means to accommodate full-scale presentation of data on X-Y recorders.