Abstract: A power converter comprises a power transformer having a primary winding and a secondary winding flux coupled to the primary winding, input terminals for receiving an input voltage, and output terminals for providing an output voltage. A power switching arrangement comprising two pairs of switching devices arranged in a bridge configuration has a corresponding duty cycle which is selectable so as to cause the power converter to manifest different input output transfer characteristics corresponding to buck and boost modes of operation. An inductor having a single winding is coupled between the input terminals and the primary winding through the switching devices. Secondary winding rectification and filtering provides the power supply output.

Abstract: A vibration damper assembly for a ring resonator of a vibrating structure gyroscope has a female portion attachable to a body of the gyroscope so as to have limited resiliency with respect to the body in a direction substantially perpendicular to the body. A male portion is fixedly attachable at one end to a resonator of the gyroscope, projectable into the female portion and fixedly attachable at its other end in and to the female portion. The assembly permits damping of vibratory movement of the resonator in a direction substantially perpendicular thereto whilst retaining stiffness and freedom to vibrate for the resonator in the plane thereof.

Abstract: Provided are systems for attaching one or more explosive device(s) to a flexible linear support, related methods and devices, and methods of using the charge assemblies thus produced.

Abstract: A lift arrangement for conveying a load between two levels in a lift shaft, said lift arrangement comprising two platform means each mounted for movement within said lift shaft between one level and the other, each platform means being changeable between a load-carrying configuration in which it extends across a substantial extent of the lift shaft, and a bypass configuration in which it allows the other floor means to pass it when in a load carrying configuration.

Abstract: An internally threaded blind rivet nut is provided. The nut includes adjacent a clinchable region 14 thereof a resilient collar 18 or peripheral region dimensioned such that in use, when the rivet nut is clinched, it is capable of limited axial and/or radial float.

Abstract: A method and apparatus for controlling the penetration depth of a cutting tool of a numerically controlled machine. A substantially cylindrical collar extends around at least part of the cutting tool with the collar being axially movable with respect to the axis of rotation of the cutting tool. An electronic sensor, secured to a non-rotatable housing of the numerically controlled machine transmits a signal to terminate further penetration of the cutting tool. The sensor is situated adjacent the collar and axially rearward thereof. A locking pin is provided for preventing an axially rearward end of the collar from touching an axially forward end of the electronic sensor when the collar is not being subjected to a force acting in a rearward axial direction. A nose bush for pre-positioning of the collar relative to the cutting tool in the axial direction is advantageously provided.

Abstract: The present invention provides a fiber optic link utilizing asymmetric homodyne modulation and balanced detection to achieve a very high dynamic range. The link uses a Mach Zehnder Modulator to generate a double-sideband suppressed-carrier signal from a laser light signal of a carrier frequency and a modulating signal at a modulating frequency. The laser light signal is phase shifted and injected into the double-sideband suppressed-carrier signal. Two signals are generated wherein the fundamental components are out-of-phase. The two signals are input to a balanced receiver wherein the one signal is subtracted from the other, resulting in the fundamental components adding, thereby providing an improved fundamental signal.

Abstract: A mixing method and mixer structure provide a circuit topology suitable for use in radio receivers, transmitters, tuners, instrumentation systems, telemetry systems, and other systems and devices performing frequency conversion in either homodyne or heterodyne implementations. The inventive mixer may be used for wireless communication devices including radios, cellular telephones, and telemetry systems whether land, sea, airborne, or space based, and whether fixed or mobile. The mixer provides superior intermodulation and harmonic distortion suppression and features excellent conversion loss, noise figure, port match, and port isolation as a result of its circuit topology. The mixer device circuit combines the advantages of series mixing FETs, a triple balanced design using a balanced passive reflection transformer, a precise local oscillator phase splitter, and square wave gate drive having high slew rate signal characteristics to achieve high levels of performance.

Abstract: An electromagnetic levitation device comprises an electromagnet (12) which is supported by a structure (13) and is arranged to attract armature (10) carried by another structure (11). Current to the electromagnet (12) is regulated by a control device (16) to ensure that the electromagnetic force exerted by the electromagnet (12) on the armature (10) is sufficient to cause and maintain levitation of the structures (11, 13) at a desired spacing (A in FIG. 1). A decoupling device (17) is arranged between the armature (10) and the structure (11) to accommodate a shock load (L) which reduces the flux gap (15) to zero and decouples the armature (10) from its support structure (11) by moving the stop (20) away from the structure (11). This significantly increases the extent of shock loading that can be tolerated before damage will be incurred.

Abstract: A vessel comprises a cylindrical hull (10) containing a structure (11) carrying machinery (M) supported from the hull (10) by electromagnetic levitation means (12-17) that maintain electromagnetic forces between flux gaps (24) which are arranged to extend radially of the adjacent hull (10) curvature and longitudinally of the hull (10). In this manner, the transmission of noise from the machinery (M) to the hull (10) is obviated so as to reduce the detectable acoustic signal emitted by the vessel and furthermore, radial expansion or contraction of the hull (10) is prevented from mechanical transmission to the structure (11) via the levitation means (12-17).

Abstract: A radio comprising an FET mixing device for multiplying a first-frequency signal with a second frequency signal to generate a third frequency analog mixer output signal. A local oscillator input port receives a periodic sinusoidal local oscillator signal at a local oscillator frequency from an external local oscillator source. A drive circuit generates a substantially square-wave two-voltage level switching signal for driving said mixing device. An analog-to-digital converter generates a digital representation of said third frequency analog mixer output signal.