Abstract: A converter operating in a resonant mode of operation is used as an off-line switching power supply operating with a high power density. A drive arrangement and operative scheme for driving the power switching transistors limits the dissipation losses within the power switching transistors. Drive circuitry drives two power switching transistors with unequal duty cycles having conducting durations such that the sum of the conduction intervals substantially equals the combined switching period of the two power switching transistors. These conducting intervals are separated by very short dead time intervals controlled by the differing turn-on and turn-off times of the two power switching transistors. The short interval between alternate conductions of the two power switching transistors is sufficient in duration to allow zero voltage turn on of the power switching transistors but short enough in duration to minimize power loss and conducted noise.

Abstract: A drive arrangement and operative scheme for the power switching transistors of a half-bridge power drives the two power switching transistors with unequal duty cycles having conducting durations such that the sum of the conduction intervals substantially equals the combined switching period of the two power switching transistors. The conducting intervals are separated by very short dead time intervals controlled by the differing turn-on and turn-off times of the two power switching transistors. The short interval between alternate conductions of the two power switching transistors is sufficient to allow zero voltage turn on of the power switching transistors but short enough to minimize power loss and conducted noise.Special biasing is provided to prevent drive signal application to power switches prior to attainment of a minimum voltage across the switch.Circuitry is provided for cancellation of output ripple currents at selected operating points of the power converter.

Abstract: Holdover circuitry for an off line switcher, including a DC-to-DC converter, maximizes holdover time, during source voltage failures, by commutating a precharged holdover capacitor to the input of a power factor correcting preregulator. This limits the size of the holdover capacitor required without any loss in holdover time. Reduction in the size of the required holdover capacitor required for a desired holdover time improves volumetric efficiency of the off line switcher. This arrangement further improves efficiency of the DC-to-DC converter and decreases stress on its components by narrowing the input voltage range requirement.

Abstract: A pressure relief valve, according to the invention, is mounted on a vent orifice providing a gas passageway from an interior plenum of a battery or a cell thereof to the ambient atmosphere. The valve fits on the vent orifice and opens to release gas at a high threshold battery gas pressure and reseals the vent orifice when the internal pressure of the battery drops to a low threshold.

Abstract: A mobile data telephone capable of transmitting and/or receiving voice and/or data signals over cellular communication channels or other air interfaces comprises a radio transceiver and a data modem in the same physical package. The transceiver and the modem have their respective controllers coupled so that they are effectively linked to achieve control of data transfer therebetween. In response to communication channel conditions in the air interface, the data flow between the modem and an audio processor of the transceiver can be selectively altered yielding high performance and high quality data transfer rates in the presence of severe channel impairments.

Abstract: A signal delay assembly for a high power linear amplifier, using feedforward circuitry to reduce distortion, comprises an interdigital delay line unit with included directional couplers. The structure of the interdigital delay line is substantially in a parallelepiped housing. A co-axial connector constructed as an integral part of the delay unit is used for signal connection to the amplifier.

Abstract: A personal communicator handset is designed to operate as both a handset and as a speakerphone and to automatically switch between the two modes based on distance between the handset and the user's ear. This distance is determined by an infrared range detection unit built into the handset.

Abstract: A battery charger control includes a thermal sensor attached to the battery being charged. If the temperature readings indicate a thermal runaway condition the charging current output is adjusted in accord with the temperature reading by means of voltage injeciton into an output sense lead of the charging circuitry as a means of achieving a control that prevents thermal runaway of the battery while still permitting continuous charging of the battery.

Abstract: A metrology system to analyze panel misregistration in a panel manufacturing process includes a software controlled system which checks defined panel parameters on the four corners of a panel and related artwork for processing with a master pattern etched on a glass reference with a machine vision measuring system. The panel or artwork being checked is positioned by panel center registration means to align the center of the panel with the center of the master pattern. Displacement and rotational differences are entered under software control into a data base and analyzed by a stored program intelligent analyses system into a plurality of parameters based on a parameter model which permits an analysis of the cause of the misregistration.

Abstract: A battery reconnect scheme is provided to permit battery replacement in a power reserve system without requiring the manual switching of the battery terminals into and out of the circuitry. A battery reconnect circuit is provided to perform the functions normally performed manually during the replacement of a discharged battery with a fresh battery. These functions also include checking the operability of circuitry to be powered by the newly inserted battery.

Abstract: A linear bearing slide assembly comprises an outer member, an inner member, a pair of linear bearing mechanisms, a preloading bar and a longitudinal spring. The outer member has a primary channel opening for accepting the inner member, and two secondary channel openings for accepting the linear bearing mechanisms and a preloading assembly. The inner member is located in the primary channel opening of the outer member. The first and second linear bearing mechanisms are located in the secondary channels on opposite sides of the primary channel opening. These linear bearing mechanisms support and guide the inner member as it travels along the primary channel opening in the outer member. Each of the linear bearing mechanisms can be conventionally constructed with either sliding or a plurality of rolling elements between two bearing ways.

Abstract: In many applications involving the coding and processing of speech signals the relevant applicable codebook is one which may be termed a sparse codebook. That is, the majority of elements in the codebook are zero valued. The searching of such a sparse codebook is accelerated in accord with the present invention by generating auxiliary information defining the sparse nature of the codebok and using this information to assist and speed up searches of the codebook.In a particular method of searching the calculation of the distance between a target vector and a stored codebook vector is enhanced by use of a distortion metric derived from energy terms and correlation terms of the codebook entries. Calculation of these energy and correlation terms is speeded up by exploiting the sparseness of the codebook entries. The non-zero elements (NZE) of the space codebook are each identified and are defined by their offset from a reference point.

Abstract: A bus bar comprised of a layered stack of flexible conductive planar leaf conductors, with sufficient cross-sectional current carrying capacity, is used in a bulk rectifier for conducting heavy currents between components. The bus bar is amenable to being easily coupled to mounting structures having mounting pad planes at different levels and angular positions. It is normally uninsulated and hence heat exchange is enhanced compared with traditional insulated cable. This permits the bus bars to operate at a relatively low temperature.

Abstract: A magnetic component (i.e. inductor or transformer) utilizes sheet winding patterns designed to enhance component assembly and maximize utilization of the core window areas. The windings are obtained from a copper sheet from which sheet winding patterns are obtained by etching, stamping or cutting the copper sheet. These winding patterns are contoured to fit precisely into the window area of the core of the magnetic component so that the window area is fully utilized. Basic symmetrical copper sheet patterns are used and these are sequentially stacked and combined to achieve multiple turn windings. These assembled winding components are connected to a bobbin which includes pins at its periphery to interconnect the copper sheet winding patterns to obtain the desired number of turns of the windings.

Abstract: A voice mail notification arrangement provides an audible notification to a mobile radiotelephone subscriber that one or more incoming calls have been redirected to the subscriber's mailbox.An unanswered incoming call is directed to the voice mail system which stores the calling party's voice message. A flag is set in a feature data base which includes this feature for the called subscriber. When the subscriber subsequently originates a call from their cellular mobile radiotelephone, or answers any incoming call, an audible notification (e.g., a burst of special tone) is provided, via the speaker of the mobile radiotelephone handset, to alert the subscriber at the outset of an active call that there are one or more voice messages in his/her voice mailbox. The flag is cleared when the voice messages are retrieved or upon the first call originated by the mobile subscriber, depending upon the mode of operation active in the subscriber's system.

Abstract: The antennas of a cellular telephone system are each connected to a signal divider/combiner array which/divides combines the antenna connecting path(s) into a plurality of antenna-radio/radio-antenna connecting paths. The divider array aspect is used for signal reception and the combiner array aspect is used for signal transmission. Each of these antenna connecting paths is connected to a controllable switch which in turn selectively couples it to/from a second plurality of radio transceivers. The antenna transmission/receive paths comprising the signal divider/combiners are embodied as strip type transmission lines in a multi layer PCB with all the paths having equal transmission losses. Micro vias are provided to permit electrical access to the various layers. The controllable switches are surface mounted on the outside of the PCB and are coupled to the various dividers/combiner through the micro vias.

Abstract: An interdigital resonant cavity filter structure is foled to provide two adjacent chambers physically positioned side by side and electrically connected in series with each other. A center plate divides the two chambers with a slot at one end of the structure to permit the two chambers to function as one resonant cavity in a folded relation to each other. Each chamber includes interdigital resonators which are related to the overall resonant cavity to produce a band pass filter action within the folded resonant cavity. The input of the filter structure is applied through a port of a circulator connected to one end of the resonant cavity and the output is taken from another port of the circulator. The opposite end of the resonant cavity is terminated in the characteristic impedance of the resonant cavity thereby causing the overall structure to operate as a high quality notch filter.

Abstract: Hardware complexity of transmitting and receiving equipment in a CDMA (Code Division Multple Access) cellular radio transmission system, embodying the principles of the invention, is reduced by the use of frequency modulation (FM) techniques to achieve spectral spreading in combination with signal modulation.The spectral spreading technique of a CDMA cellular radio telephone communications system is generalized by extending the range of values allotted to the spreading waveform code signal to include complex numbers of unity magnitude. This permits the addition of a baseband version of the information signal and spreadying waveforms instead of the conventional multiplication of the two signals in existing DSSS (Direct Sequence Spread Spectrum) communications sytems. The resultant summed signal is used to control a VCO (Voltage Controlled Oscillator) to produce a frequency modulated spread signal to be transmitted.