Abstract:
The invention relates to a bail latching device for an opto-electronic transceiver, including a pivotal latching member and a bail. The bail includes ends extending at an acute angle from a plane defined by the side arms for pivoting the latching member when the bail is rotated from a rest position to a removal position. Ideally, in the rest position, the side arms of the bail extend downwardly on each side of a front end of the transceiver. In the removal position, the bail is parallel to a removal direction, whereby the bail rotates the latching member to an unlatching position and then provides a handle to grasp while removing the transceiver from a standard cage.
Abstract:
An optical packaging arrangement combines a planar lightwave circuit (PLC) having an array of waveguides thereon, an array of photodetectors on a substrate to receive light beams coupled out of the PLC by the output ports, and a collimating faceplate, having a plurality of glass cores, extending between the PLC and the photodetector array for coupling the output light beams to respective photodetectors. The faceplate forms a cover for a hermetic cavity encompassing the photodetectors. The PLC is disposed either co-planarly with the faceplate or transversely to it. Light from the PLC is tapped via a plurality of taps formed on the PLC for coupling to the photodetectors.
Abstract:
The present invention is a method of estimating formation properties by analyzing acoustic waves that are emitted from and received by a bottom hole assembly.
Abstract:
A multi-phase DC-DC converter architecture in which parameters including error signal gains and modulator gains are defined so as to balance multiple converter channel currents, irrespective of whether the converter channels are supplied with the same or different input voltages.
Abstract:
A soft start circuit for a DC-DC converter has an input reference voltage coupled to an error amplifier and to a soft start capacitor. A feedback resistor is coupled between an output node and the error amplifier, whose output is coupled to a pulse width modulator (PWM). The PWM output is coupled through an inductor to the output node, to which an output capacitor referenced to ground is coupled. Means is provided to charge up the soft start capacitor to the output voltage while the converter is disabled. As a result, when enabled, the converter will not discharge the output capacitor, but will ramp the output voltage to the voltage Vref without excessive currents.
Abstract:
A laser apparatus is disclosed utilizing a laser diode having a reflective back facet and a front facet having a reflectance of less than about 1% for emitting an optical beam at a fundamental frequency along an optical path. A collimating lens is provided for collimating the optical beam into a collimated beam. A transmission grating is optically coupled to receive the collimated beam and returns a portion of the collimated beam back into the laser diode by means of diffraction through lens and the laser diode front facet. The laser diode reflective back facet and the transmission grating form an extended laser cavity. In operation, a substantial portion of the collimated beam is transmitted through the transmission grating for producing the laser output beam propagating along the optical path.
Abstract:
An arrangement for measuring current through a phase section of a buck mode DC-DC converter includes an auxiliary integrated circuit containing an auxiliary power MOSFET and a pilot MOSFET coupled in parallel with a current path through a high side MOSFET of a half-bridge of the converter. The pilot MOSFET has a current path coupled to a current measurement terminal. The MOSFETs of the auxiliary circuit are time division multiplexed with the high side MOSFET, whereby a determination of current through the auxiliary high side MOSFET is based upon current through the pilot device and the geometric ratio of the size of the pilot device to that of the high side auxiliary MOSFET. The high side MOSFET is activated for a large number of switching cycles relative to the pilot circuitry, but the pilot circuitry is activated sufficiently often to derive a relatively accurate measure of current flow.
Abstract:
A control circuit for a switch mode DC-DC converter contains an arrangement of monitored LGATE, UGATE and PHASE node condition threshold detectors, outputs of which are processed in accordance with a switching control operator to ensure that each of an upper FET (UFET) and a lower FET (LFET) is completely turned off before the other FET begins conduction, thereby maintaining a dead time that exhibits no shoot-through current and is independent of the type of switching FET.
Abstract:
An athermal interferometric wavelocker is disclosed having a beam splitter combiner and a first arm of a first material having a first refractive index, a first length, and a first coefficient of expansion; and, a second arm of a second material having a second refractive index, a second length, and a second coefficient of expansion. The refractive indices, lengths and coefficients of expansion of the first arm and the second arm are selected to provide a substantially athermal structure operating at ambient temperatures. The first arm and second arm have inner end faces that meet adjacent faces of the beam splitter and combiner. The first and second arms are of a different optical path length such that light launched into the beam splitter and combiner, interferes upon recombining, and is output from a combiner output port to provide a wavelocker signal having a detectable characteristic which varies with wavelength.
Abstract:
Absorbable polyester fibers, braids, and surgical meshes with prolonged strength retention have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available, and could offer additional benefits such as anti-adhesion properties, reduced risks of infection or other post-operative problems resulting from absorption and eventual elimination of the device, and competitive cost. The devices may also be particularly suitable for use in pediatric populations where their absorption should not hinder growth, and provide in all patient populations wound healing with long-term mechanical stability. The devices may additionally be combined with autologous, allogenic and/or xenogenic tissues to provide implants with improved mechanical, biological and handling properties.