Abstract: A power supply includes a storage component to store an output current value representative of a magnitude of output current supplied by an output voltage of a power converter to power a load. The power supply further includes an offset reference generator and a controller. The offset reference generator produces an offset reference signal, the output current value being offset by the offset reference signal. The controller controls generation of the output voltage of the power converter as a function of the offset output current value with respect to a threshold signal (value). Additionally, the controller is configured to detect a startup mode of a power converter operative to convert an input voltage into an output voltage. During the startup mode, the controller: i) produces a threshold signal having a magnitude that varies over time, and ii) controls operation of switches in the power converter as a function of the threshold signal while the power converter is operated in a diode emulation mode.

Abstract: A power supply includes a storage component to store an output current value representative of a magnitude of output current supplied by an output voltage of a power converter to power a load. The power supply further includes an offset reference generator and a controller. The offset reference generator produces an offset reference signal, the output current value being offset by the offset reference signal. The controller controls generation of the output voltage of the power converter as a function of the offset output current value with respect to a threshold signal (value). Additionally, the controller is configured to detect a startup mode of a power converter operative to convert an input voltage into an output voltage. During the startup mode, the controller: i) produces a threshold signal having a magnitude that varies over time, and ii) controls operation of switches in the power converter as a function of the threshold signal while the power converter is operated in a diode emulation mode.

Abstract: A power supply includes a storage component to store an output current value representative of a magnitude of output current supplied by an output voltage of a power converter to power a load. The power supply further includes an offset reference generator and a controller. The offset reference generator produces an offset reference signal, the output current value being offset by the offset reference signal. The controller controls generation of the output voltage of the power converter as a function of the offset output current value with respect to a threshold signal (value). Additionally, the controller is configured to detect a startup mode of a power converter operative to convert an input voltage into an output voltage. During the startup mode, the controller: i) produces a threshold signal having a magnitude that varies over time, and ii) controls operation of switches in the power converter as a function of the threshold signal while the power converter is operated in a diode emulation mode.

Abstract: An apparatus comprises an emulator and a corresponding compensator. During operation, the emulator produces, at different instants of time, an emulated output current value representative of an amount of current supplied from an output voltage to a load. In general, the compensator provides selective compensation to the emulated output current value over time. For example, for a first time duration, compensation adjustments from the compensator are used to modify the emulated output current value. For a second duration of time, compensation adjustments from the compensator are not used to modify the emulated output current value. Disabling or discontinuing application of adjustments (such as based on the actual measured output current) during the second time duration (such as during a respective transient condition) provides more accurate and timely generation of a respective emulated output current value.

Abstract: A power converter includes a switch, an ON-time controller, and a compensator. Over multiple control cycles, the ON-time controller controls an ON-time duration of a control signal driving the switch. Activation of the switch generates an output voltage that powers a dynamic load. The ON-time controller controls attributes such as a switching frequency and/or an ON-time duration of the control signal driving the switch to regulate the output voltage. A phase-locked loop in the compensator supplies the ON-time controller with adjustment signals that adjust the ON-time duration of activating the switch to maintain the switching frequency at a desired setpoint. Thus, if a transient load condition causes the ON-time controller to temporarily operate the switch to at a value other than the desired setpoint frequency, the phase-locked loop of the compensator causes the switching frequency to align with the desired switching frequency again over one or more control cycles.

Abstract: A power converter includes a switch, an ON-time controller, and a compensator. Over multiple control cycles, the ON-time controller controls an ON-time duration of a control signal driving the switch. Activation of the switch generates an output voltage that powers a dynamic load. The ON-time controller controls attributes such as a switching frequency and/or an ON-time duration of the control signal driving the switch to regulate the output voltage. A phase-locked loop in the compensator supplies the ON-time controller with adjustment signals that adjust the ON-time duration of activating the switch to maintain the switching frequency at a desired setpoint. Thus, if a transient load condition causes the ON-time controller to temporarily operate the switch to at a value other than the desired setpoint frequency, the phase-locked loop of the compensator causes the switching frequency to align with the desired switching frequency again over one or more control cycles.

Abstract: An apparatus comprises an emulator and a corresponding compensator. During operation, the emulator produces, at different instants of time, an emulated output current value representative of an amount of current supplied from an output voltage to a load. In general, the compensator provides selective compensation to the emulated output current value over time. For example, for a first time duration, compensation adjustments from the compensator are used to modify the emulated output current value. For a second duration of time, compensation adjustments from the compensator are not used to modify the emulated output current value. Disabling or discontinuing application of adjustments (such as based on the actual measured output current) during the second time duration (such as during a respective transient condition) provides more accurate and timely generation of a respective emulated output current value.

Abstract: A system for reclaiming sand from a casting process includes a chamber having an inlet, an outlet, and a plurality of baffles defining a circuitous path for the sand therebetween, a heating element for providing heat to the chamber, and a fluidizing distributor for directing the sand through the chamber. A method of reclaiming waste sand also is provided.

Abstract: Disclosed is a method for dislodging a mold from a casting formed within the mold. The mold may be removed from the casting by scoring the mold and applying a force sufficient to cause the mold to fracture and break into pieces. Additionally, the mold may be fractured by either explosive charges placed in the mold pack or by high energy pulsations directed at the mold. Once the mold is fractured and broken into various pieces it may then be dislodged from the casting.

Abstract: Disclosed is a method for dislodging a mold from a casting formed within the mold. The mold may be removed from the casting by scoring the mold and applying a force sufficient to cause the mold to fracture and break into pieces. Additionally, the mold may be fractured by either explosive charges placed in the mold pack or by high energy pulsations directed at the mold. Once the mold is fractured and broken into various pieces it may then be dislodged from the casting.

Abstract: A control circuit for a piezo transformer based power supply for a fluorescent lamp includes driver circuitry generating pulse waveforms for providing excitation to primary inputs of the piezo transformer, and circuitry for regulating lamp current and the voltage across the piezo transformer primary inputs. The frequency of the pulse waveforms is varied in response to the magnitude of lamp current to maintain a predetermined desired lamp current as represented by a current reference signal. The duty cycle of the driver circuitry is varied in response to the magnitude of the voltage across the piezo transformer primary inputs to maintain a predetermined desired piezo primary voltage as represented by a voltage reference signal. The piezo transformer is operated as close to resonance as possible, contributing to greater circuit efficiency. The driver circuitry in the control circuit employs four transistors arranged as a full bridge with respect to the piezo transformer primary inputs.

Abstract: A circuit breaker IC adapted for controlling an external NMOS switch coupled between a supply voltage and a load referenced to ground, with the circuit breaker being isolated from ground. With this arrangement, the voltage across the circuit breaker is limited, thereby permitting use of a low voltage integrated circuit fabrication process. The circuit breaker includes a sensor for sensing load current through the switch and providing an output signal indicative of the load current, a charge pump providing a supply voltage and an amplifier responsive to the sensor output signal and to the charge pump supply voltage for providing a drive signal to control the switch.

Abstract: A panel mounted aircraft cockpit instrument is provided with a specially designed illuminating section which is used to light the instrument without causing interference with the operation of night vision equipment in the cockpit. An infrared light-filtering illuminating section is removably secured within a front-accessible recessed portion of the instrument and includes a sealed, filtered housing in which one or more incandescent bulbs are disposed. Each bulb is resiliently supported within its housing using a resilient, electrically resistive yet relatively highly heat conductive supporting material. Heat generated by the bulb is conducted outwardly through its supporting material into a metal heat sink portion of the housing and then externally dissipated therefrom. The illuminating structure may be easily and quickly removed and replaced without the necessity of removing the instrument or gaining access to the rear of the panel.

Abstract: A gyroscopic referenced electronically operated grade and slope attitude indicator enabling a heavy equipment operator to build a slope and/or grade by visual readout. It is a system using a gyro output to compute the grade and slope for display thereof on a dual steering bar indicator. An angle calibration along with cancelling switches allows an equipment operator a selection of slope and grade ratios to work to in a work approach making staking and restaking of a slope and/or grade unnecessary other than for a surveyed starting point with a toe-stake or its equivalent.