Abstract: An active current sharing circuit that provides a plurality of paralleled DC-DC converters each having a lossless inductor-based current sensing circuit for sensing the average current of the associated DC-DC converter through its output inductor, and a means for adjusting the voltage reference coupled to each of the DC-DC converter's PWM controllers through a one pin interconnection between the converters. The circuit provides a high percentage current sharing level at lower cost, with reduced circuit wiring complexity, and fewer components. In an alternate embodiment, the inductor-based current sensing is replaced with a resistor-based current sensing, such that comparable current sharing levels are achieved albeit with higher loss.

Abstract: A telecommunications power system includes a power bus and a battery module with a plurality of batteries. A contactor connects the batteries to the power bus. A distribution module and a plurality of rectifier modules are connected to the power bus. A plurality of loads are connected by the distribution module to the power bus. A controller disconnects the batteries using the contactor when a voltage of the batteries falls below a low voltage disconnect threshold when AC power is lost and/or the rectifier modules fail. The controller minimizes current surge and high voltage transients when the rectifier modules begin providing power and the contactor closes to reconnect the batteries to the power bus. To minimize current surge and high voltage transients, the controller lowers a voltage of the rectifier modules to the voltage of the batteries before the contactor reconnects the batteries to the power bus.

Abstract: A circuit that efficiently prevents the turning on of the synchronous rectifier in a buck converter during a predetermined condition, so as to prevent current reversing through the synchronous rectifier during that time. In one embodiment, the circuit provides control of the synchronous rectifier during the soft-start time for a non-isolated DC-DC buck converter, thereby preventing current reversing (sinking), referred to as the back bias condition, during its soft start process. In another embodiment, a circuit uses a signal indicative of a soft-start condition for a converter to prevent the turning on of the synchronous rectifier during the soft-start time. A corresponding system solves the aforementioned synchronous rectifier back bias problem for converters used in a paralleled converter configuration.

Abstract: A method of manufacturing a large stationary, aggregate processing screening tower by fabricating weldment modules and preassembling them with aggregate processing equipment internal within the weldment modules, transporting the preassembled weldment modules to a field work site where the tower is to be erected on a foundation, aligning the modules and stacking the modules in layers and then bolting adjacent modules together. A large stationary, aggregate processing screening tower has weldment modules preassembled with aggregate processing equipment internal within the modules. The preassembled modules are stacked up on one another and secured together and can receive aggregate product at the top module and the product is processed by screening and sizing as it moves downwardly by gravity through the modules and their processing equipment for final clarification and collection of the product.

Abstract: An automatic configuration system for a telecommunications power system includes a power bus and a communications bus. A controller that is connected to the communications bus employs a serial communications protocol. A module transmits an identification signal to the controller that contains an identification number of the module. The modules include rectifier modules, battery connection modules and distribution modules. Each module transmits the identification signal after the module is initially connected to the power bus and the communications bus. The controller receives the identification signal from the module. The controller stores the identification number and generates a module ID for the module that is transmitted to the module for use by the module in further serial communications with the controller.

Abstract: A pulse width modulation controlling circuit for a power supply and method for controlling a switchmode power supply in a computer is disclosed. The present invention accomplishes control over the switching of the power supply by coarsely and then finely adjusting a time-length signal.

Abstract: A power converter is provided that operates with a wide range input and provides the required hold up time using a smaller, less costly hold-up capacitor. A charging circuit is provided to charge a capacitor through an auxiliary winding. The power converter includes circuitry for channeling the energy from the capacitor to the converter to provide hold-up time during input power loss conditions, while having better utilization of stored energy. The power converter of the present invention also provides this function using fewer and lower cost components than prior art devices.

Abstract: A multi-output DC-DC power supply has programmable operating characteristics, such as voltage levels, turn-on and off sequences, mono-phase and multi-phase operation, voltage ramp-up and ramp-offs, tracking and protection mode thresholds and action-if-fault strategies. The power supply has a DC-DC converter having an output coupled to a plurality of buck converters. Each buck converter has an output and a control input where the voltage at the output of the buck converter is determined by a duty cycle of at least one pulse width modulated signal provided at the control input of that buck converter. A programmable device has outputs coupled to the control inputs of the buck converters. The programmable device generates the pulse width modulated signals at its outputs for controlling the buck converters to provide voltages corresponding to voltages programmed in the programmable device.

Abstract: A low-power planar transformer for cell phone chargers or the like includes a primary bobbin structure carrying connection pins aligned for mounting the transformer in a through-hole configuration or directly on a circuit board, and a secondary bobbin structure that fits wholly within the primary bobbin structure.

Abstract: The present invention provides for an apparatus and corresponding method for controlling inrush current in an AC-DC power converter by providing a control circuit to limit inrush current efficiently during cold startup, warm startup, and power line disturbance conditions. The present invention controls inrush current without the need for an extra series lossy dissipative device and without causing undesirable voltage surges at the input of the DC—DC converter stage. The preferred embodiment includes use of the present invention for AC-DC converters having active power factor correction.

Abstract: The present invention provides a system and method for providing power to electronic devices such as cellular telephones and accessories thereof. A power converter module, which may be either an AC or DC module and which delivers accessory usable power, mates with an accessory module through a pair of mating connectors. By supplying a standard interface between converter and accessory modules, a system of interchangeable modules can be used to produce accessories without duplication of what would otherwise be redundant components. The invention thus provides flexibility and reduces the cost and clutter of prior art systems and methods for powering cell phone accessories.

Abstract: A slope gap inductor for reducing line harmonic currents. The slope gap inductor comprises a first inductor core portion, and a second inductor core portion positioned relative to said first inductor core portion so as to form an inductor gap, wherein the second inductor core portion includes a sloped gap surface that forms a sloped gap portion of the inductor gap having a varying gap height, and wherein the sloped gap surface has a slope value that is selected so that the slope gap inductor has a selected inductance value responsive to a level of current in the inductor.

Abstract: A burner assembly including a housing having an air inlet and a burner end. An impeller that is mounted in the housing is in communication with the air inlet and adapted to direct air toward the burner end of the housing. The burner assembly also includes an inner air tube that is mounted in the burner end of the housing so as to define an inner combustion zone and an outer combustion zone.

Abstract: A zero voltage switching (ZVS) or zero voltage transition (ZVT) bridge converter for driving a rectifier circuit. A clamp winding or inductor is placed in parallel with a resonant choke of the bridge converter. The clamp winding clamps the voltage at the resonant choke. Clamping the resonant choke in turn limits the voltage at the secondary winding of an output transformer. The output transformer is connected to the rectifier circuit. By limiting the voltage at the output transformer, the voltage at the rectifier circuit is limited as well.

Abstract: An automated battery configuration system for a telecommunications power system includes at least one rectifier module, a controller and at least one backup battery. A database system is associated with the controller stores a plurality of records that include a plurality of backup battery parameters. A user interface that is associated with the controller receives user-provided input of at least one battery specifying parameter. The user interface communicates with the database system to retrieve a selected one of the records based on the battery specifying parameter. The controller communicates with the database system and employs at least one of the parameters of the selected record to alter an operating setting of the telecommunications power system. The battery specifying parameters include a manufacturer designation and a model designation of the backup battery.

Abstract: A plug assembly having a body portion, a plug housing that provides a mounting for AC prongs that creates a cavity therewithin, and a PCB located in the cavity. A pair of contact terminals are mounted on the PCB in a predetermined position so as to create a spring-loaded electrical contact with a corresponding one of the AC prongs during assembly. The present invention reduces the bulkiness, optimizes the packaging size, and reduces the profile of the plug assembly by using the cavity to house the PCB, thereby providing a reduction or elimination of the need to mount components within the body portion. The present invention eliminates the need to use flexible wires, springs, or direct soldering between the AC prongs and the circuitry on the PCB, thereby making assembly quicker and easier through use of the spring loaded contact terminal.

Abstract: An electrical adapter having a manually retractable cable assembly where the electrical contacts of the retractable cable assembly are disposed along an axis of rotation to minimize the friction between the cable and contacts therein when the cable is extended and retracted. The electrical adapter includes a housing; an electrical plug assembly including an interchangeable module coupled to an adapter module, the interchangeable module having a plurality of prongs for receiving a first voltage when mated with an electrical receptacle, and a converter electrically coupled to the assembly for converting the first voltage into a second voltage; and a retractable cable assembly supported by the housing and electrically coupled to the converter.

Abstract: A circuit for controlling the switching behavior of a field effect transistor (FET) or other power switch in a power supply or converter. The circuit includes an adaptive feedback loop which controls the switching operation of the FET through application of a gate drive signal to the device. The circuit is designed to turn the switching device on or off at the optimum time to reduce the stress and power losses associated with the switching action. The circuit includes a capacitor connected to the FET switch drain to sense the falling voltage across the switch. The adaptive gate drive circuit holds the FET switch off until the drain voltage sensed by the capacitor stops decreasing. At this time, the FET switch voltage is either zero (zero-voltage switching) or has reached the minimum value of its resonant ring (low-voltage switching).

Abstract: Processor-implemented monitor and control modules gather operating data from the rectifier units, battery connection units and power distribution units. From these data, statistical operating data are calculated and stored in a database managed by the resident processor within the power system control unit. The system expansion analysis module analyzes the statistical data in view of a set of predetermined warning and alarm threshold parameters, which may be factory specified or user settable. If an alarm or upgrade condition is detected, the system expansion analysis module generates an upgrade notification that is optionally sent in a variety of forms including local audible or on screen notification, remote alarm through network connection to a remote computer, via internet web browser and e-mail message. The system can also optionally initiate automated order processing to place orders for upgrade or expansion equipment and installation services.

Abstract: A method of manufacturing a large stationary, aggregate processing screening tower by fabricating weldment modules and preassembling them with aggregate processing equipment internal within the weldment modules, transporting the preassembled weldment modules to a field work site where the tower is to be erected on a foundation, aligning the modules and stacking the modules in layers and then bolting adjacent modules together. The stacked-up modules are adapted to receive aggregate at the top uppermost module and permit the aggregate to be processed by screening, blending, and sizing into aggregate product as it moves downwardly by gravity through the modules and their processing equipment for final collection of the product at the ground level. A large stationary, aggregate processing screening tower has weldment modules preassembled with aggregate processing equipment internal within the modules.