Abstract: Prepositioning of a phase lock loop by charging or discharging the loop filter capacitor to a voltage close to the desired VCO control voltage is accomplished rapidly by the addition of a current pump. The current pump, responsive to a tuning voltage corresponding to the VCO control voltage provides a pulse of high rate current to charge or discharge the capacitor. The current pulse, which is of sufficient length to ensure that the capacitor achieves the desired voltage, swamps out the contribution of the loop charge pump which is responsive to the loop phase detector. When disabled, the current pump appears as a virtual open circuit to the loop capacitor, so that no current leakage occurs through the current pump.

Abstract: A power switching amplifier for digital power amplification of an analog input signal, wherein the input signal range is subdivided into a plurality of equal voltage steps and a number, corresponding to the number of voltage steps, of switching stages is driven and their direct-voltage sources are connected in series. The association between the voltage steps and the switching stages is variable, such that all switching stages are uniformly loaded and the switching frequencies are reduced.

Abstract: A signal processing circuit includes a differential amplifying circuit for respectively generating first and second output signals from first and second output terminals, first and second input terminals of this circuit being respectively coupled to a signal input terminal and a constant voltage terminal, first and second transistors coupled between a power source terminal and the signal input and output terminals, third and fourth transistors coupled between the signal input and output terminals and a ground terminal, a fifth transistor which together with the first transistor constitutes a first current mirror circuit and allows the current corresponding to the second output signal to flow through the first transistor and also allows the current corresponding to the second output signal to flow through the second or fourth transistor, and a second current mirror circuit for leading the currents corresponding to the first output signal to the third transistor and to the fourth or second transistor.

Abstract: A microwave cavity oscillator has a semiconductor device, for example a transistor for exciting the cavity to oscillate. The device is mounted upon a substrate which is itself mounted, conveniently soldered, upon a carrier which is releasably secured in a chamber adjacent the cavity. The carrier and substrate are mounted so that the device is coupled to the cavity via a hole extending therebetween and can be removed and installed as a sub-assembly to facilitate tuning and other adjustments in a test bed. In preferred embodiments one end of the carrier is located in spigot-and-socket fashion in a recess surrounding a hole communicating with the cavity. The other end of the carrier is urged by spring means to positively and accurately locate the carrier relative to the cavity. A part of the substrate extends through the hole and into the cavity. The transistor is mounted on the part within the hole and the part within the cavity serves as a capacitive coupling probe.

Abstract: An improvement in a microwave oscillator using a GaAs FET as the active element is shown to include a phase detector responsive to a portion of the positive feedback signals applied to a resonator having a high Q and to a portion of the signals out of the GaAs FET, shifted by 90.degree., to obtain signals to degenerate noise internally formed in the GaAs FET.

Abstract: A differential amplifier is disclosed which comprises: a first differential amplifying circuit comprising first and second transistors of an NPN type, the collector of the first transistor constituting an output terminal of the amplifier; a second differential amplifying circuit comprising third and fourth transistors of the NPN type whose bases are inverting and noninverting input terminals, respectively, the base of the third transistor being connected to the collector of the second transistor, and the base of the fourth transistor being supplied with a bias voltage; a first load circuit for the first differential amplifying circuit, the first load circuit comprising a fifth transistor of a PNP type forming a collector load for the second transistor and a sixth transistor of the PNP type for forming a collector load for the first transistor, the bases of the fifth and sixth transistors being connected to the collector of the fourth transistor; and a second load circuit for the second differential amplifying

Abstract: A cylinder or barrel fitted with cams is used to limit the outward movement of spring-loaded plungers attached to cavity shorting bars in a klystron. Different tunings of the klystron are achieved by rotating the cylinder so that different rows of cams limit the plungers. A linear solenoid is used to decouple the plungers from the cams before rotation. A stepping solenoid is used to move the cylinder from one setting to another.

Abstract: A broadband distributed amplifier capable of amplifying frequencies from zero to 20 Gigahertz is disclosed having a singly terminated output. The singly terminated construction of the amplifier precludes the need for a termination resistor on the output and thereby enables substantially all of the output power to be utilized.

Abstract: Identification of migratory animals, such as adult fish and the like, by means of implanted coded tags, with tag coding involving one or more higher atomic numbered chemical elements in stable, solid form (elements with atomic numbers 40-42, 44-53, 55-60 and 62-83), the elements being identified in the live animal by selective X-ray irradiation of the implanted tag and spectral analysis of the fluorescent X-ray radiation emitted by the tag. Rapid analysis of the fluorescent X-ray radiation to identify the coding element(s) with a high level of confidence is obtained by use of high intensity irradiation and controlled masking to essentially confine the irradiation to only the tag and the animal tissue immediately surrounding the tag and thereby improve the signal-to-noise ratio of the fluorescent X-ray radiation emitted by the coding element(s).

Abstract: A photographic lighting system, particularly for use in photographic studios, including a constant light for illuminating the subject to be photographed while the subject is being placed in proper position and while the photographer is focusing the camera, plus an electronic flash device for illuminating the subject while the actual photograph is being taken. The constant or continuous light is adjustable to vary the degree of illumination produced thereby, and the duration of the electronic flash is automatically adjusted to vary the duration of the flash, in response to the adjustment of the brilliance of the continuous light. The electronic flash tube is powered by a storage capacitor, and charge control means determines the voltage to which the storage capacitor is charged in preparation for an ensuing flash. Blocking means prevents the initiation of a flash unless the storage capacitor is charged to the proper voltage.

Abstract: An electronic flash apparatus includes a correct exposure annunciator which operates if light received from the subject exceeds a predetermined percentage of the required illumination.

Abstract: A detecting unit for automatic tune selection apparatus of a phonographic record player comprising a light projector and a CdS photoelectric element housed in a casing, said casing having a cylindrical light shield barrel extending axially downwardly therefrom having a constricted aperture formed thereon at the lower end portion thereof so as to form a limited passage for exclusive reception of the reflection of light rays from its own light source, warding off all the reflections of the light source from outside, thereby ensuring accurate actuation of said detecting unit for the automatic tune selection system without any incidental failure.

Abstract: A device for replacing a fluorescent lamp in a two lamp serially connected fluorescent fixture either of the type which includes a rapid-start type transformer for every two rapid-start fluorescent lamps or an instant start fixture for every two instant start lamps. By placing the device in the fixture in place of one of the two lamps the remaining lamp is energizable to provide illumination, whereas without the device the remaining lamp is inactive.