432 results about "RC time constant" patented technology

Voltage regulators often have coupled output inductors because coupled output inductors provide improvements in cost and efficiency. Coupled inductors are often used in multi-phase voltage regulators. Feedback control of voltage regulators often requires accurate and responsive sensing of output current. Provided is a technique for accurately sensing the magnitude of output current in coupled inductors. An RC circuit (comprising a resistor and capacitor in series) is connected in parallel with the coupled inductor. The inductor has a leakage inductance Lk and a DC (ohmic) resistance of DCR. The resistor and capacitor are selected such that an RC time constant is equal to an L/R time constant of Lk/DCR. With the matching time constants, a sum of voltages on the capacitors is accurately proportional to a sum of currents flowing in the output inductors. Also provided is a technique for sensing current when an uncoupled center tap inductor is present.

Systems and methods are disclosed that facilitate determining coil temperature in a proximity sensor, such as an extended range inductive proximity sensor. Voltage measurements can be taken before, and during, damped oscillatory decay of a voltage in a resonant circuit in the proximity sensor to determine a value, γ, associated with an inductive time constant for the resonant circuit. The gamma value comprises information related to both inductance and resistance in the sensor coil, and can be employed to determine coil temperature. Derivation of the gamma value, and thus of coil temperature, can utilize a current pulse of a duration of approximately one RC time constant of the resonant circuit, thus mitigating current consumption by the proximity sensor during temperature assessment.

A high frequency divider circuit for producing output signals of half the frequency of an input clock signal includes two identical circuit sections, each producing an output signal and its complement. The circuit sections are connected to each other so that the output signals of one circuit section serve as input signals to the other circuit section. Each circuit section contains a load transistor which is controlled by one of the clock signal and the clock signal complement, and a switch transistor which is controlled by the other of the clock signal and the clock signal complement. The inventive circuit exhibits a reduced RC time constant for each circuit section and an increased output signal swing between the output signals and their respective complements, as contrasted with prior art frequency dividers, thereby increasing the overall circuit response time and its ability to operate at high frequencies.

The invention relates to a tuning circuit for tuning a filter stage, which has an RC element (1) with an RC time constant (τ), with the RC time constant (τ) being the product of the resistance of a resistor (R1) in the RC element (1) and the capacitance of a capacitor (C1), which is connected in series with the resistor (R1), in the RC element (1), having a comparator (10) for comparison of the voltage which is produced at the potential node (4) between the resistor (R1) and the capacitor (C1), with a reference ground voltage; and having a controller (15) which varies the charge on the capacitor (C1) in the RC element (1) until the comparator (10) indicates that the voltage which is produced at the potential node (4) is equal to the reference ground voltage, with the controller (15) switching a capacitor array (26) as a function of the charge variation time, which capacitor array (26) is connected in parallel with the capacitor (C1) in the RC element (1), in order to compensate for any discrepancy between the RC time constant (τ) of the RC element (1) and a nominal value.

An arrangement for protecting an element from electro-static discharge. A switch is provided to inhibit the flow of energy through the element in response to the control signal. In the illustrative embodiment, the switch is a transistor switch. A resistor is disposed between an input terminal of the transistor and the positive supply to keep the transistor on during normal operation. A capacitor is disposed between the input terminal of the transistor and ground to prevent the input voltage of the transistor from fast changing. The RC time constant is chosen to be much larger than the time constant of the ESD pulse. Consequently, input voltage of the transistor will remain unchanged near ØV and the transistor will remain off during ESD event preventing the element from conducting the discharge current and providing ESD protection.

A slab laser includes two elongated electrodes arranged spaced apart and face-to-face. Either one or two slabs of a solid dielectric material extend along the length of the electrodes between the electrodes. A discharge gap is formed either between one of the electrodes and one dielectric slab, or between two dielectric slabs. The discharge gap is filled with lasing gas. A pair of mirrors is configured and arranged to define a laser resonator extending through the gap. An RF potential is applied across the electrodes creating a gas discharge in the gap, and causing laser radiation to circulate in the resonator. Inserting dielectric material between the electrodes increases the resistance-capacitance (RC) time constant of the discharge structure compared with the RC time constant in the absence of dielectric material. This hinders the formation of arcs in the discharge, which enables the laser to operate with higher excitation power, higher lasing gas pressure, and higher output power than would be possible without the dielectric inserts.

This invention is concerned with the control of implanting ions into a substrate, such as doping semiconductor wafers. The ion beam is measured to ensure waters are implanted with the correct, uniform ion dose. The incident ion beam comprises ions and neutrals, yet detectors measure only ions. The ions/neutrals ratio varies with the ion implanter's chamber pressure that in turn is known to rise and fall when the ion beam is on and off the wafer respectively, according to a characteristic time constant. This invention provides methods of correcting measured ionic currents to account for neutrals using the time constant. Initially an assumed time constant is used that is later improved by measuring the ionic current after a delay sufficient to allow the chamber pressure to recover to its base value. The time constant may also be improved by removing any quadratic variation in already determined true beam current values.

A controller, for force-controlling a drive source of a controlled object, having a position control circuit inside a force control circuit in order to define a relative position of the controlled object to a workpiece, and a contact force occurred between the workpiece and the controlled object, the controller including a first data acquiring portion for acquiring a time constant of the position control circuit based on a position command value to the drive source and an actual position value, during operations of the controlled object; a second data acquiring portion for acquiring a rigidity value for the controlled object and the workpiece based on a force data obtained when the controlled object is brought into contact with the workpiece; and an automatic gain calculating portion for calculating a force control gain of the force control circuit from the time constant of the position control circuit acquired by the first data acquiring portion and the rigidity value acquired by the second data acquiring portion, under conditions where a time constant of the force control circuit is larger than the time constant of the position control circuit.

A fully alternating current (AC) coupled multi-point, multi-drop or point-to-point bus interconnect uses a low power synchronous pulsed signaling scheme for board-level chip-to-chip communication. A single-ended or differential pulsed signaling transceiver generates a diamond data eye with a small time constant in the pulsed signal. The transceiver includes a high-pass filter or a differentiator circuit network that generates triangle pulses that make the diamond data eye.

A method for calculating a primary time constant of a power grid. It comprises the steps of: establishing an electromechanical transient model of the power grid using the widely used power system analysis software package (PSASP) according to the actual power grid parameters and network topology; establishing an electromagnetic transient model under PASAP using the actual power grid parameters for a site which requires the calculation of the primary time constant of the power grid, and setting a ground short circuit fault at the site; obtaining a transient short circuit current of the short circuit point of the power grid using a hybrid simulation method of the electromechanical and electromagnetic transient models; filtering out a periodic component in the transient short circuit current to obtain a non-periodic component attenuated with time, and finding the attenuation time constant of the non-periodic component which is the primary time constant of the power grid.

A method for RC time constant tuning includes biasing a reference resistor and charging a reference capacitor, transmitting a start signal to a counter when beginning charging, inputting the results of biasing and charging to a comparator for comparing, and sending a stop signal to the counter when the result of the comparison conforms to a predetermined rule, counting a number of clock cycles received by the counter from the time of receiving the start signal to the time of receiving the stop signal, and deciding a number of resistors or a number of capacitors utilized by an RC filter according to the number of the clock cycles received by the counter.

A voltage regulator includes a transistor, a comparator, and a compensation circuit. The comparator has a first input terminal coupled to receive a clock signal, a second input terminal, and an output terminal coupled to a control electrode of the transistor. The compensation circuit has a first input terminal coupled to receive a reference voltage, a second input terminal coupled to the output terminal of the voltage regulator, and an output terminal coupled to the second input terminal of the comparator. The compensation circuit has a filter circuit. The filter circuit has a first RC time constant during startup of the voltage regulator, and the filter circuit has a second RC time constant during normal operation. Changing the RC time constant for startup prevents an overshoot of an output voltage of the voltage regulator.

An electromagnetic operator includes first and second coils wound coaxially An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

A pulsed modulated capacity modulation system for refrigeration, air conditioning or other types of compressors is disclosed in which suitable valving is provided which operates to cyclically block flow of suction gas to a compressor. A control system is provided which is adapted to control both the frequency of cycling as well as the relative duration of the on and off time periods of each cycle in accordance with sensed system operating conditions so as to maximize the efficiency of the system. Preferably the cycle time will be substantially less than the time constant of the load and will enable substantially continuously variable capacity modulation from substantially zero capacity to the full capacity of the compressor. Additional controls may be incorporated to modify one or more of the motor operating parameters to improve the efficiency of the motor during periods of reduced load.