Abstract: An Automated Teller Machine (ATM) terminal receives a transaction request from a user. The ATM terminal triggers a camera to capture a first image of the authentication media item presented by the user, where the first image of the authentication media item is embedded with a first unique code. The ATM terminal compares the first image of the authentication media item with a second image of the authentication media item that is associated with the user, where the second image of the authentication media item is embedded with a second unique code for verifying the user. The ATM terminal determines whether the first unique code corresponds to the second unique code. The ATM terminal conducts the transaction request if it is determined that the first unique code corresponds to the second unique code.

Abstract: A controlled release microcapsulate pharmaceutical formulation for burst-free, sustained, programmable release of hydrophobic bioactive agent over a duration from 24 hours to 100 days comprising: and a blend of end-capped uncapped biocompatible, biodegradable poly(lactide/glycolide).

Abstract: A controlled release microcapsulate pharmaceutical formulation for burst-free, sustained, programmable release of hydrophobic bioactive agent over a duration from 24 hours to 100 days comprising: and a blend of end-capped uncapped biocompatible, biodegradable poly(lactide/glycolide).

Abstract: A controlled release microcapsulate pharmaceutical formulation for burst-free, sustained, programmable release of hydrophocib bioactive agent over a duration from 24 hours to 100 days comprising: and a blend of end-capped uncapped biocompatible, biodegradable poly(lactide/glycolide).

Abstract: An impedance network for passive shoot-through protection of active switches in clamp-mode topologies. In one exemplary embodiment a switch-mode converter, includes: a primary switch; an auxiliary switch coupled in series with a capacitor; and an impedance network, coupled to the primary switch and the auxiliary switch; configured to limit current during simultaneous conduction of the primary and auxiliary switches. The impedance network includes a resistor coupled in series to a diode and both in parallel with an inductor. The impedance network permits the design of a clamp-mode converter without the need for a delay between switch turn-off and turn-on of primary and auxiliary switches.

Abstract: A method and apparatus for dynamically adjusting operation of a converter device to improve conversion efficiency. The converter device includes an inverter and a synchronous rectifier, and is driven by a plurality of drive signals having a duty cycle. The method comprises the steps of: (a) varying timing of a first drive signal a first amount; (b) observing the duty cycle of the conversion device; (c) further varying the first drive signal appropriately to alter the duty cycle toward an extremum; and (d) continuing to operate the converter device with the duty cycle proximate the extremum. In its most preferred embodiment, the method of the present invention includes the further step of: (e) periodically effecting steps (a)-(c) varying a drive signal other than the first drive signal. The comprises: (a) a drive varying means for varying timing of selected individual drive signals of the plurality of drive signals; and (b) a measuring means connected with the drive varying means for measuring the duty cycle.

Abstract: A power factor controller, a method of controlling power factor and a power converter employing either the controller or the method. The controller includes: (1) a ramp circuit that senses an output voltage of a converter being controlled and generates an intermediate waveform that rises as a function of a magnitude of the output voltage and (2) a drive circuit, coupled to the ramp circuit, that senses a current in the converter and causes the intermediate waveform to fall at a time that is a function of a magnitude of the current, the drive circuit generating a drive signal for the converter from the intermediate waveform.

Abstract: For use with a power converter having a main output and an auxiliary output and an auxiliary regulating switch that regulates a voltage at the auxiliary output, a transient response network, and method of diverting energy from the main output to the auxiliary output. In one embodiment, the transient response network, includes: (1) an energy diverting switch interposed between the main output and the auxiliary output, and (2) a control circuit, coupled to the energy diverting switch, that senses a characteristic of the power converter and causes the energy diverting switch to conduct a current in response to a substantial load reduction at the main output thereby diverting energy from the main output to the auxiliary output.

Abstract: A lossless snubber circuit is described for use with power converters, particularly asymmetric half-bridge converters. The snubber circuit provides a clamping circuit which has a clamping diode and a clamping capacitor connected across each of the rectifier diodes in the power converters output circuit. The clamping diode and clamping capacitor act to clamp the voltage across the rectifier diode and to recover the reverse recovery energy from the rectifier diode's turn-off. The reverse recovery energy is then transferred back to the input capacitors of the converter's input circuit through an energy recovery circuit. The energy recovery circuit includes a recovery switch which regulates the operation of the snubber circuit and a commutation transformer which provides the path from the snubber circuit to the input circuit. The snubber circuit allows the clamping voltage of the clamping capacitor to be adjusted to accommodate changes in the converter's conditions.

Abstract: A control system for an converter circuit using two interleaved boost circuits is described which uses a single PWM controller to control the switches in both of the interleaved boost circuits. A voltage feedback control circuit monitors the output voltage of the converter circuit and sends that information to the PWM controller. A current sensing circuit is provided that senses the current in each of the boost converters. The current sensed in the current sensing circuit is converted to a voltage and used in conjunction with the voltage information from voltage feedback control circuit by the single PWM controller to regulate both of the boost converter switches. By regulating the boost converter switches, the single PWM controller is able to ensure proper synchronization and current sharing while tightly regulating the output voltage and improving the input power factor of the converter circuit.

Abstract: A power factor correction system with an EMI line filter at the input includes circuitry to sense the capacitor current of the EMI filter to improve the accuracy of the power factor enhancement. The circuitry consists of a current sensing means connected after the EMI filter, and a voltage sensing capacitor which derives its input signal from a pair of diodes separate from the conventional 4-diode rectifier bridge, which are connected either before or after the EMI filter. The current-sensing means, which may be a resistor, and the voltage-sensing capacitor are tightly coupled to the current control loop of the power factor correction system to compensate for the current in the EMI filter capacitors.

Abstract: A split boost converter is disclosed herein, suitable for both single phase and three phase AC input applications. It provides two equal but unparallelable output voltages stored on two separate independent output capacitors. The implementation supports two modes of operation in which two power switches are operated simultaneously or alternately. Each mode maintains the advantage of a reduced boost inductor size. In the first mode the charging of the capacitors in parallel circuits and their discharge in a series connection substantially reduces ripple current in the inductor permitting the user of a smaller inductor. In the second mode the capacitors are charged and discharged in differing time intervals achieving a similar result. The circuit is operable with input voltages which must exceed the voltages of its two output capacitors.

Abstract: A rectifier for a switching power supply or the like. The recitifier has a plurality of diodes coupled in parallel, each diode having in series therewith a saturable inductor and a node disposed between the diode and the inductor to form a diode/inductor pair. At least one resistor is connected between at least two of the nodes to assure nearly equal current flow in the diodes. Alternatively, a link winding on at least two of the inductors are coupled together to achieve current balancing.

Abstract: A power factor correction system with an EMI input filter includes circuitry to sense the capacitor current of the filter to improve the accuracy of the power factor enhancement by providing a split current sensing resistor connected to the EMI filter or a voltage sensing capacitor. Both arrangements may be tightly coupled to the current control loop of the power factor control and compensate for the unsensed current in the EMI filter capacitors.