Abstract: A circuit for closing a relay when an active AC voltage connected to one of the contacts of the relay is approximately zero volts includes a monitoring circuit that monitors the active AC voltage and outputs a phase-shifted voltage that crosses zero volts at predetermined times before the active AC voltage traverses zero volts. A pulse generating circuit initiates a pulse when the phase-shifted voltage enters a predefined voltage region and terminates the pulse when the voltage exits that region. An input signal is strobed onto the control input of the relay by the pulse so that the relay changes state coincident with the zero crossing of the active AC voltage.

Abstract: A pulse-width modulated apparatus to convert an input voltage to an output voltage at advantaged duty-cycles utilizes more than two switches in a converter design. The switches implement current paths that allow a single primary winding to be formed of primary winding segments. Intermediate points in the transformer primary winding are connected to switches and diodes such that during the OFF phase of the duty-cycle, the transformer segments discharge more quickly, thereby allowing the ON Phase of the duty-cycle to be longer than the OFF phase. During the OFF phase, the switches isolate the segments from each other while the diodes provide a magnetizing current discharge path. An output stage connected across the secondary winding regulates the output voltage by implementing a forward converter.

Abstract: A pulse-width modulated apparatus to convert an input voltage to an output voltage at advantaged duty-cycles utilizes more than two switches in a converter design. The switches implement current paths that allow a single primary winding to be formed of primary winding segments. Intermediate points in the transformer primary winding are connected to switches and diodes such that during the OFF phase of the duty-cycle, the transformer segments discharge more quickly, thereby allowing the ON Phase of the duty-cycle to be longer than the OFF phase. During the OFF phase, the switches isolate the segments from each other while the diodes provide a magnetizing current discharge path. An output stage connected across the secondary winding regulates the output voltage by implementing a forward converter.

Abstract: A circuit for closing a relay when an active AC voltage connected to one of the contacts of the relay is approximately zero volts includes a monitoring circuit that monitors the active AC voltage and outputs a phase-shifted voltage that crosses zero volts at predetermined times before the active AC voltage traverses zero volts. A pulse generating circuit initiates a pulse when the phase-shifted voltage enters a predefined voltage region and terminates the pulse when the voltage exits that region. An input signal is strobed onto the control input of the relay by the pulse so that the relay changes state coincident with the zero crossing of the active AC voltage.

Abstract: A power factor and crest factor correction circuit for a power distribution network of the type comprising a low power source for supplying a plurality of ports with an ac signal is disclosed. Each port comprises a rectifier bridge, a bulk storage capacitor and a power converter connected across the rectifier bridge, The power factor and crest factor correction circuit comprises an inductor, series connected between the rectifier bridge and the bulk capacitor, for reducing the current peaks in a rectified signal received from the rectifier bridge. The correction circuit also comprises diode means connected in parallel across the inductor for discharging the bulk capacitor whenever the voltage across the bulk capacitor exceeds the voltage of the rectified signal. As a result, a higher power factor is obtained for the dc signal applied to the power converter, and also the current peaks in the dc signal are substantially reduced.

Abstract: An exterior rear view mirror for a motor vehicle has a housing containing a reflective member and being adapted to be secured to a bracket, mounted on the vehicle body, by first and second arms. Each arm is pivotally connected to the bracket for relative angular movement about a pivot axis. In order to hold the housing at a predetermined orientation relative to the bracket means, a first pair of detent formations on the second support element diametrically spaced on opposite sides of the pivot axis is adapted to engage with a first pair of complementary formations on one face of a washer located between the second support element and the bracket means, and a second pair of detent formations on the opposite face of the washer diametrically spaced apart from one another relative to the pivot axis and orientated at 90.degree. to the first pair of complementary formations, the second pair of detent formations, is adapted to engage with a second pair of complementary formations on the bracket.

Abstract: In a telephone switching facility, line circuits are arranged in groups, each including a local ringing battery bus, and a universal high level signal generator (UHLSG) for providing ringing and other high level signals to the line circuits via the local ringing bus. Each generator is responsive to address signals from a controller in the switching facility to generate selected high level signals. The UHLSG includes a switching bridge driven by a width modulated signal stream of periodically occurring pulses having assertion times suitable for developing a high level signal across a network at the output of the switching bridge. The width modulated pulses are generated from period and time signals. The period signal occurs once with each sequence in repetitively generated data byte sequences. The time signal occurs with correspondence between a selected stored data byte and an instant one of the data bytes of the sequence. A plurality of the stored data bytes are arranged in ranges in a storage circuit.

Abstract: A remotely controlled rearview mirror assembly has a tiltable reflective member mounted on a fixed base in a casing, the reflective member being tilted by means of a remote control. Two or three-wire cable systems are the preferred linkage but electrical or fluidic linkages may be used. The reflective member is anchored to the base by a forked member to prevent rotation of the reflective member, in its own plane, which would otherwise cause jamming or juddering by contact with the sides of the casing. The preferred forked member is a V-shaped wire strut with arms pivotally attached to the reflective member and a necked junction part as a frictional pivot to provide damping. The reflective member is tiltably mounted by an arcuate knife edge received in a linear groove, the included angle of the groove being greater than that of the knife edge. This provides a substantially common elevational and azimuthal pivot point closer to the surface of the reflective member.

Abstract: Safety belt retractors are disclosed in the form of spring driven belt rewinding mechanisms. In some arrangements, a pair of spiral springs act in series or in parallel, one spring applying a constant rewinding torque to a belt storage shaft, the other storing energy when the belt is withdrawn. A ratchet maintains the stored energy and is disengaged by a screw threaded actuator, which moves coaxially to the storage shaft, when the shaft rotates through a number of revolutions. The stored energy is released to supplement the rewinding torque of the first spring. In another arrangement, the ratchet is replaced by an over center spring assembly. An epicyclic gear box drives a coil spring anchorage through a given arc to give an over center action.

Abstract: A remote control for an exterior rear view mirror for vehicles in which the mirror is adjusted within a stationary housing by rotation of a single control member coupled to the mirror head and which provides adjustment of the head in at least two planes.