1377 results about "Capacitor discharge" patented technology

The present invention relates to a electrode assembly and related method that includes a insulator assembly, an electrode assembly, a charging system, a mechanism for measuring electrical voltages, a mechanism for adjusting the distance between inner and outer electrode tips, and a controller. The insulator assembly includes an insulator body having a hollow central portion with a threaded inner wall. The insulator assembly includes inner and outer conductors that are electrically connected to the charging system and are physically connected to inner and outer electrodes, respectively. The electrodes are positioned such that their longitudinal axes are aligned and the tips of the electrodes are in relatively close physical proximity. The distance between the tips is defined as the spark gap. The charging system charges a capacitor that discharges and forms a spark across the spark gap. The electrical measuring mechanism measures the discharge voltage of the capacitor and the controller compares it to a reference voltage, issuing a correction signal to the adjusting mechanism that repositions the electrodes, thus optimizing the spark gap. An alternate embodiment analyzes the charge and discharge characteristics of an electrode assembly that utilizes a second capacitor and an inductor to adjust the spark gap.

A discharge circuit for a DC power supply smoothing capacitor that is used in a power conversion device that supplies DC power via a switch to the DC power supply smoothing capacitor and an inverter, includes; a resistor that discharges charge in the capacitor; a switch connected in series with the resistor, that either passes or intercepts discharge current flowing from the capacitor to the resistor; a measurement circuit that measures a terminal voltage of the capacitor; and a control circuit that controls continuity and discontinuity of the switch; wherein the control circuit, after having made the switch continuous and starting discharge of the capacitor by the resistor, if a terminal voltage of the capacitor as measured by the measurement circuit exceeds a voltage decrease characteristic set in advance, makes the switch discontinuous and stops discharge by the resistor.

Methods and apparatus for providing uninterruptible power are provided by aspects of the invention. One aspect is more particularly directed to an uninterruptible power supply for providing power to a load. The uninterruptible power supply includes an input to receive input power, an output to provide output power, an input power circuit coupled to the input and having a DC output that provides DC power having a first DC voltage level, a capacitor having a first end coupled to the DC output of the input power circuit and having a second end, a back-up power source coupled to the input power circuit, an output power circuit coupled to the DC output of the input power circuit and to the output of the uninterruptible power supply to provide the output power, and a capacitor discharge circuit coupled to the first end of the capacitor and the second end of the capacitor and configured in a first mode of operation to discharge a voltage across the capacitor, such that an average discharge current through the discharge circuit is inversely proportional to a voltage across the capacitor for a first range of voltages across the capacitor.

A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

A main power supply continuously provides a current to a power input terminal of an integrated circuit device under test (DUT). The DUT's demand for current at the power input terminal temporarily increases during state changes in synchronous logic circuits implemented within the DUT. To limit variation (noise) in voltage at the power input terminal arising from these temporary increases in current demand, a charged capacitor is connected to the power input terminal during each DUT state change. The capacitor discharges into the power input terminal to supply additional current to meet the DUT's increased demand. Following each DUT state change the capacitor is disconnected from the power input terminal and charged to a level sufficient to meet a predicted increase in current demand during a next DUT state change.

A method and apparatus for driving lasers. An example laser driving system includes a laser current controller for providing a modulation signal and a bias signal. The modulation signal and bias signal is used by a plurality of high-speed current drivers that accept the modulation signal and the bias signal and produce a plurality of laser drive signals. The example system also has a disable input that disconnects power from a high-speed current driver when the high-speed current driver is not in use. The exemplary system develops the modulation and bias signals by feeding back a signal developed from detection of laser light from one of the lasers driven by the system. The laser may be a data laser or a control laser that is modulated by a signal having a lower frequency than the data lasers. If a control laser is used then the photodetector circuit used for feedback can have a lower frequency response because of the lower frequency of the control laser signal. The photodetector system may also employ a peak detector capacitor discharge circuit where a large capacitance is simulated by having the capacitor discharge through the base of a transistor have a current source in the emitter circuit.

A capacitive discharge ignition (CDI) system that can be used with a variety of light-duty internal combustion engines, including those typically employed by lawn, garden, and other outdoor equipment. According to one embodiment, the CDI system includes an ignition module having a first switching device that shorts a charge coil during an initial portion of a charge cycle. Subsequently, the first switching device is turned ‘off’ so that a flyback charging technique charges an ignition capacitor. A second switching device is then used to discharge the ignition capacitor and initiate the combustion process.

A circuit interrupter having an integrated variable timer circuit for alerting an end-user of an impending test of the circuit interrupter which expands the function of a basic circuit interrupter by adding visual / audible warning indicators and the capability of the circuit interrupter to test itself is described herein. The integrated variable timer circuit includes a variable resistor where the user can adjust the current flowing to a capacitor. The variable resistor enables the ability for the user to adjust the predetermined testing time. When the charge across the capacitor surpasses the voltage of a parallel, connected Zener diode, a transistor turns on a self-test subcircuit or visual / audible warning indicator. A switch across capacitor is used to discharge the capacitor and to reset the timer. A switch is included to enable a manual trip after the self test has completed.

Methods and apparatus are provided for portable medical devices such as defibrillators having different charging and operating voltages. The apparatus comprises a connection for receiving DC input voltage VIN, an energy storage device (e.g., a capacitor), a battery having at least two cells therein coupled to the connection and the capacitor, and switches to selectively reconfigure the battery cells so as to: (i) charge from VIN, and (ii) discharge to the capacitor at VOUT>VIN. The method comprises charging the battery from VIN while its cells are arranged substantially in parallel, then reconfiguring the switches to arrange some of the charged cells substantially in series to give VOUT>VIN, and then charging the capacitor therefrom. The cells are thereafter reconfigured back to the parallel arrangement ready to be recharged from VIN. Isolation switches are conveniently provided to isolate the battery from VIN while charging the capacitor.

A method for controlling an ignition system of an internal combustion engine having a primary firing pulse generator for charging a capacitor. An electronic switch is included for discharging the capacitor via an ignition coil to generate an ignition voltage. A microcomputer operates the switch to control the ignition timing of the generator. The microcomputer is in communication with a speed sensor that detects the rotational speed of the engine and a speed limitation control that limits the engine speed to a limitation speed below the clutch-in speed of an included centrifugal clutch. The speed limitation control is active or activated when one of either starting the engine or an operating problem of the power tool is detected. The speed limitation control is deactivated when a low speed state of the engine is detected.

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool in combination with an electromagnetic force generated by the interaction of the applied current with a transverse magnetic field. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous metal and the equilibrium melting point of the alloy in a time scale of several milliseconds or less, at which point the interaction between the electric field and the magnetic field generates a force capable of shaping the heated sample into a high quality amorphous bulk article via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time scale of less than one second.