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Showing papers on "Voltage regulator published in 1995"


Book
01 Oct 1995
TL;DR: In this paper, the authors present a power quality evaluation procedure for the purpose of measuring the power quality of a power supply. But, they do not define the specific classes of power quality problems.
Abstract: CHAPTER 1: INTRODUCTION What is Power Quality? Power Quality -- Voltage Quality Why Are We Concerned About Power Quality? The Power Quality Evaluation Procedure Who Should Use This Book Overview of the Contents CHAPTER 2: TERMS AND DEFINITIONS Need for a Consistent Vocabulary General Classes of Power Quality Problems Transients Long-Duration Voltage Variations Short-Duration Voltage Variations Voltage Imbalance Waveform Distortion Voltage Fluctuation Power Frequency Variations Power Quality Terms Ambiguous Terms CBEMA and ITI Curves References CHAPTER 3: VOLTAGE SAGS AND INTERRUPTIONS Sources of Sags and Interruptions Estimating Voltage Sag Performance Fundamental Principles of Protection Solutions at the End-User Level Evaluating the Economics of Different Ride-Through Alternatives Motor-Starting Sags Utility System Fault-Clearing Issues References CHAPTER 4: TRANSIENT OVERVOLTAGES Sources of Transient Overvoltages Principles of Overvoltage Protection Devices for Overvoltage Protection Utility Capacitor-Switching Transients Utility System Lightning Protection Managing Ferroresonance Switching Transient Problems with Loads Computer Tools for Transients Analysis References CHAPTER 5: FUNDAMENTALS OF HARMONICS Harmonic Distortion Voltage versus Current Distortion Harmonics versus Transients Harmonic Indexes Harmonic Sources from Commercial Loads Harmonic Sources from Industrial Loads Locating Harmonic Sources System Response Characteristics Effects of Harmonic Distortion Interharmonics References Bibliography CHAPTER 6: APPLIED HARMONICS Harmonic Distortion Evaluations Principles for Controlling Harmonics Where to Control Harmonics Harmonic Studies Devices for Controlling Harmonic Distortion Harmonic Filter Design: A Case Study Case Studies Standards of Harmonics References Bibliography CHAPTER 7: LONG-DURATION VOLTAGE VARIATIONS Principles of Regulating the Voltage Devices for Voltage Regulation Utility Voltage Regulator Application Capacitors for Voltage Regulation End-User Capacitor Application Regulating Utility Voltage with Distributed Resources Flicker References Bibliography CHAPTER 8: POWER QUALITY BENCHMARKING Introduction Benchmarking Process RMS Voltage Variation Indices Harmonics Indices Power Quality Contracts Power Quality Insurance Power Quality State Estimation Including Power Quality in Distribution Planning References Bibliography CHAPTER 9: DISTRIBUTED GENERATION AND POWER QUALITY Resurgence of DG DG Technologies Interface to the Utility System Power Quality Issues Operating Conflicts DG on Distribution Networks Siting DGDistributed Generation Interconnection Standards Summary References Bibliography CHAPTER 10: WIRING AND GROUNDING Resources Definitions Reasons for Grounding Typical Wiring and Grounding Problems Solutions to Wiring and Grounding Problems Bibliography CHAPTER 11: POWER QUALITY MONITORING Monitoring Considerations Historical Perspective of Power Quality Measuring Instruments Power Quality Measurement Equipment Assessment of Power Quality Measurement Data Application of Intelligent Systems Power Quality Monitoring Standards References Index INDEX

1,991 citations


Journal ArticleDOI
TL;DR: In this article, a three-phase power flow solution method for real-time analysis of primary distribution systems is presented, with the emphasis on modeling of dispersed generation (PV nodes), unbalanced and distributed loads, and voltage regulators and shunt capacitors with automatic local tap controls.
Abstract: This paper presents a three-phase power flow solution method for real-time analysis of primary distribution systems. This method is a direct extension of the compensation-based power flow method for weakly meshed distribution systems from single phase to three-phase, with the emphasis on modeling of dispersed generation (PV nodes), unbalanced and distributed loads, and voltage regulators and shunt capacitors with automatic local tap controls. The method proposed here is capable of addressing these modeling challenges while still maintaining a high execution speed required for real-time application in distribution automation systems. The paper also includes test results from the application of a computer program developed based on the proposed method to large primary electric distribution systems. >

818 citations


Proceedings ArticleDOI
08 Oct 1995
TL;DR: A new three phase to three-phase converter for AC motor drives is proposed that employs only eight switches and has the capability of delivering sinusoidal input currents with unity power factor and bidirectional power flow.
Abstract: A current-controlled VSI-PWM rectifier and inverter with capacitor DC link is regarded as one of the most important structures for three-phase to three-phase power conversion. This type of power converter normally requires twelve switches for the rectifier and an inverter composed of self turnoff switch such as a bipolar transistor or an IGBT with an anti-parallel diode. In this paper, a new three-phase to three-phase AC/AC power converter for AC motor drives is proposed. The proposed power converter employs only eight switches and has the capability of delivering sinusoidal input currents with unity power factor and bidirectional power flow. This paper describes the feasibility and the operational limitations of the proposed structure. A mathematical model of the system is derived using the generalized modulation theory and experimental results for steady-state and dynamic behavior are presented to verify the developed model.

253 citations


Journal ArticleDOI
TL;DR: A new step-up DC-to-DC power converter with high power density is presented, which contains no inductors or transformers and features high efficiency for this class of powers, small output voltage ripple, continuous input current, low weight and small size.
Abstract: A new step-up DC-to-DC power converter with high power density is presented. It contains no inductors or transformers. The controlled energy transfer from an unregulated voltage source to a regulated output voltage is realized through a switched-capacitor circuit. The operation of the switches in the power stage is dictated by a PWM-type feedback circuit. The new regulator is simulated by using an averaged state-space approach. The transient and steady-state waveforms, as well as the AC small-signal input-to-output and control-to-output transfer functions are obtained by both simulation and experiments. The power supply, implemented for a nominal power of 15 W, and input-to-output voltage ratio of 5/12, features high efficiency for this class of powers, small output voltage ripple, continuous input current, low weight and small size. >

244 citations


Patent
05 Sep 1995
TL;DR: In this paper, a switching voltage regulator achieves high efficiency by automatically switching between a PFM mode and a PWM mode by monitoring the output voltage and the output current, wherein the regulator operates in PFM at small output currents and in PWM at moderate to large output currents.
Abstract: A switching voltage regulator achieves high efficiency by automatically switching between a pulse frequency modulation (PFM) mode and a pulse-width modulation (PWM) mode. Switching between the modes of voltage regulation is accomplished by monitoring the output voltage and the output current, wherein the regulator operates in PFM mode at small output currents and in PWM mode at moderate to large output currents. PFM mode maintains a constant output voltage by forcing the switching device to skip cycles when the output voltage exceeds its nominal value. In PWM mode, a PWM signal having a variable duty cycle controls the switching device. A constant output voltage is maintained by feedback circuitry which alters the duty cycle of the PWM signal according to fluctuations in the output voltage.

208 citations


Patent
04 May 1995
TL;DR: A voltage regulation circuit (45) as mentioned in this paper is a circuit that includes a sample and hold circuit for sampling an input voltage (Vin) and a regulator circuit that outputs an output voltage using the reference voltage supplied by the capacitor (C1, 515), which is used to provide high precision programming voltage for programming memory cells having two or more analog states.
Abstract: A voltage regulation circuit (45) that includes a sample and hold circuit (501) for sampling an input voltage (Vin). The sample and hold circuit (501) includes a capacitor (C1, 515) that holds the reference voltage. The voltage regulation circuit (45) also includes a regulator circuit (503) coupled to the capacitor (C1) of the sample and hold circuit (501). The regulator circuit (503) outputs an output voltage using the reference voltage supplied by the capacitor (C1). The voltage regulation circuit (45) may be used to provide a high precision programming voltage for programming memory cells having two or more analog states.

179 citations


Proceedings ArticleDOI
08 Oct 1995
TL;DR: In this article, a flux-weakening scheme for an interior permanent magnet synchronous motor (IPMSM) is proposed based on the output of the synchronous PI current regulator-reference voltage to PWM inverter.
Abstract: A novel flux-weakening scheme for an interior permanent magnet synchronous motor (IPMSM) is proposed. It is implemented based on the output of the synchronous PI current regulator-reference voltage to PWM inverter. The onset of flux weakening and the level of the flux are adjusted inherently by the outer voltage regulation loop to prevent the saturation of the current regulator. Attractive features of this flux weakening scheme include no dependency on the machine parameters, the guarantee of current regulation at any operating condition, and smooth and fast transition into and out of the flux weakening mode. Experimental results at various operating conditions including the case of detuned parameters are presented to verify the feasibility of the proposed control scheme.

176 citations


Journal ArticleDOI
TL;DR: In this paper, a neural network based maximum power tracking controller for interconnected PV power systems is presented, where the neural network is utilized to identify the optimal operating voltage of the PV power system.
Abstract: This paper presents a neural network based maximum power tracking controller for interconnected PV power systems The neural network is utilized to identify the optimal operating voltage of the PV power system The controller generates the control signal in real-time, and the control signal is fed back to the voltage control loop of the inverter to shift the terminal voltage of the PV power system to its identified optimum, which yields maximum power generation The controller is of the PI type The proportional and the integral gains are set to their optimal values to achieve fast response and also to prevent overshoot and also undershoot Continuous measurement is required for the open circuit voltage on the monitoring cell, and also for the terminal voltage of the PV power system Because of the accurate identification of the optimal operating voltage of the PV power system, more than 99% power is drawn from the actual maximum power >

176 citations


Journal ArticleDOI
TL;DR: In this paper, a new approach covering all the main aspects of secondary voltage control; pilot buses and control generators selection, the control law and the decentralization problem, is presented.
Abstract: Secondary voltage control was introduced in some European countries as a means to improve voltage security and operation. It is a closed loop system dedicated to keep the voltage of some load buses called pilot buses constant. In this paper, a new approach covering all the main aspects of secondary voltage control; pilot buses and control generators selection, the control law and the decentralization problem, is presented. This approach has been applied to the Spanish power system. Some of the results obtained are also presented.

152 citations


01 May 1995
TL;DR: The proposed converter system can solve the voltage unbalance problem of the conventional multilevel voltage-source converters, without using any additional voltage balance circuits or separate voltage sources.
Abstract: In this paper, a multilevel voltage-source converter system is proposed for high-voltage, high-power applications such as back-to-back interconnection of power systems, large induction motor drives, and electrical traction drives. Multilevel voltage-source converters have a voltage unbalance problem in the DC capacitors. The problem may be solved by use of additional voltage regulators or separate DC sources. However, these solutions are found not to be practicable for most applications. The proposed converter system can solve the voltage unbalance problem of the conventional multilevel voltage-source converters, without using any additional voltage balance circuits or separate voltage sources. The mechanism of the voltage unbalance problem is analyzed theoretically in this paper. The voltage unbalance problem of multilevel converters in the DC capacitors has been solved by the proposed internal connections of the AC/DC and DC/AC converters. The validity of the new converter system is demonstrated by simulation and experiment. >

142 citations


Proceedings ArticleDOI
18 Jun 1995
TL;DR: In this paper, a multilevel voltage-source converter system is proposed for high-voltage, high-power applications such as back-to-back interconnection of power systems, large induction motor drives, and electrical traction drives.
Abstract: In this paper, a multilevel voltage-source converter system is proposed for high-voltage, high-power applications such as back-to-back interconnection of power systems, large induction motor drives, and electrical traction drives. Multilevel voltage-source converters have a voltage unbalance problem in the DC capacitors. The problem may be solved by use of additional voltage regulators or separate DC sources. However, these solutions are found not to be practicable for most applications. The proposed converter system can solve the voltage unbalance problem of the conventional multilevel voltage-source converters, without using any additional voltage balance circuits or separate voltage sources. The mechanism of the voltage unbalance problem is analyzed theoretically in this paper. The voltage unbalance problem of multilevel converters in the DC capacitors has been solved by the proposed internal connections of the AC/DC and DC/AC converters. The validity of the new converter system is demonstrated by simulation and experiment. >

Patent
12 Oct 1995
TL;DR: In this paper, an improved alternator/starter testing device includes an electronic voltage regulator for regulating the output of an externally regulated alternator and a selectable load switch allowing so-called "high output" alternators to be tested without damaging the voltage regulator.
Abstract: An improved alternator/starter testing device includes an electronic voltage regulator for regulating the output of an externally regulated alternator A selectable load switch allows so-called "high output" alternators to be tested without damaging the voltage regulator For certain types of internally regulated alternators, the testing device includes a meter disconnect circuit, coupled to an "energize" switch in the testing device, which operates to disconnect the testing meter during a period in which the energize switch is temporarily depressed to supply power to an internally regulated alternator under test, thus preventing misleading test results if a defective alternator is tested Internal thermal circuit breakers are provided at strategic locations in the testing device to prevent internal circuit damage due to defective alternators and starters A delay off timer circuit disconnects power from a starter under test after a predetermined time period in order to prevent damage to the starter due to overtesting

Patent
Robert E. Stengel1
10 Mar 1995
TL;DR: In this article, a voltage regulator (200) includes a controller (204) which selectively activates a plurality of switching means (208, 210, 214, and 212) in order to select between a first current loop in which an energy storage device is charged by an input supply and a second loop coupled to the output terminal (242) of the regulator, the switching from the second current loop to the first is governed by the controller determining that the loop current in the second loop has reached a predetermined level.
Abstract: A voltage regulator (200) includes a controller (204) which selectively activates a plurality of switching means (208, 210, 214, and 212) in order to select between a first current loop in which an energy storage device is charged by an input supply and a second loop in which the energy storage device is coupled to the output terminal (242) of the regulator (200). The switching from the second current loop to the first is governed by the controller (204) determining that the loop current in the second loop has reached a predetermined level. A first switching audio amplifier (300) is disclosed which uses the voltage regulator (200) to provide a continuously variable output voltage (318) in order to provide for high quality amplification which is independent of the volume setting. A second audio amplifier (400) includes a converter (436) which provides discrete voltage levels to a full wave bridge in order to provide improved audio output.

Proceedings ArticleDOI
06 Nov 1995
TL;DR: In this article, the authors proposed a new voltage source inverter referred to as a boost inverter or boost DC-AC converter, which is intended to be used in UPS design, whenever an AC voltage larger than the DC link voltage is needed.
Abstract: This paper proposes a new voltage source inverter referred to as a boost inverter or boost DC-AC converter The main attribute of the new inverter topology is the fact that it generates an AC output voltage larger than the DC input one, depending on the instantaneous duty-cycle This property is not found in the classical voltage source inverter which produces an AC output instantaneous voltage always lower than the DC input voltage Operation, analysis, modulation, control strategy and experimental results are included in this paper The new inverter is intended to be used in UPS design, whenever an AC voltage larger than the DC link voltage is needed, with no need of a second power conversion stage

Journal ArticleDOI
TL;DR: In this article, the authors proposed a new performance index that provides a direct relationship between its value and the amount of load demand that the system can withstand before collapse, which can answer questions such as: "can the system withstand another 100 MVar increase on bus 11?"
Abstract: Voltage collapse is generally caused by either of two types of power system disturbances: load variations; and contingencies. A number of performance indices intended to measure the severity of the voltage collapse problem have been proposed in the literature. However, few of these performance indices can answer questions such as: "can the system withstand another 100 MVar increase on bus 11?" This paper presents a new performance index that provides a direct relationship between its value and the amount of load demand that the system can withstand before collapse. One of the features that distinguishes the proposed performance is its development in the load-demand space and its ability to answer questions such as: "can the system withstand a simultaneous increase of 70 MW on bus 2 and 50 MVAr on bus 6?" This feature makes the performance index readily interpretable to operators. Moreover, the computation involved in the proposed performance index is relatively inexpensive in comparison with those required in existing solutions. Simulation results on the IEEE 39-bus system and a 234-bus power system are presented with promising results. >

Patent
03 Jul 1995
TL;DR: In this article, the operating signals are asserted at nominal levels at start up to allow the processor to operate at a reduced, yet adequate performance level, and the stored operating parameters are asserted onto a processor data bus by the processor during start up and stored in corresponding data latches.
Abstract: A configuration system including a processor having memory for storing operating parameters and configuration logic for retrieving the operating parameters and configuring a computer system to achieve a desired performance level. The configuration logic preferably includes programmable regulators, such as a voltage regulator and a clock synthesizer, for asserting an operating voltage and clock signal, respectively, to the processor. These operating signals are asserted at nominal levels at start up to allow the processor to operate at a reduced, yet adequate performance level. The stored operating parameters are asserted onto a processor data bus by the processor during start up and stored in corresponding data latches. The parameters are further provided to the programmable regulators, such as a voltage regulator, a clock synthesizer, for example, which convert the operating signals from the nominal levels to optimal levels corresponding to the retrieved parameters. The operating signals may further be dynamically reconfigured by storing new parameters in the data latches, if desired. Thus, the regulators may be dynamically reconfigured during operation to achieve operating criterion, such as slowing down the clock frequency during a low power mode.

Patent
07 Jun 1995
TL;DR: In this article, a switching voltage regulator is described which provides multiple independently regulated outputs, which can be implemented as an integrated circuit and may have various topologies, such as boost, buck, flyback or SEPIC.
Abstract: A switching voltage regulator is described which provides multiple independently regulated outputs. A switch control independently monitors two or more voltage outputs and generates control signals for driving a main switch and two or more auxiliary switches to charge selective ones of the outputs which have fallen below their target voltages. Time sequencing techniques are utilized to control the switching of the auxiliary switches such that energy stored in an inductor is transferred to the appropriate voltage outputs. The switching voltage regulator may be implemented as an integrated circuit and may have various topologies, such as boost, buck, flyback or SEPIC.

Patent
24 Jan 1995
TL;DR: In this paper, the voltage regulator includes two sections, a switching regulator section (12) for regulating a voltage from an input (10) to an intermediate node (14), this voltage on the intermediate node is then regulated with a linear regulator down to a regulated output voltage on an output node (18).
Abstract: The voltage regulator includes two sections, a switching regulator section (12) for regulating a voltage from an input (10) to an intermediate node (14). This voltage on the intermediate node (14) is then regulated with a linear regulator down to a regulated output voltage on an output node (18). The linear regulator includes a pass transistor (16) that is controlled by a linear regulator control (50). Linear regulator control (50) is operable to sense the voltage across the transistor (16) and perform multiple functions. First, it controls the pass element transistor (16) to regulate the voltage from the node (14) to the node (18) in a linear manner. Second, it controls the switching regulator section (12) to provide a regulated voltage on the node (14). Third, it controls the level of the voltage on the intermediate node (14) such that it is at a predetermined voltage level above the voltage on the output node (18), such that the power dissipation through the pass element transistor (16) is minimized.

Patent
29 Sep 1995
TL;DR: In this article, a voltage regulator for nonvolatile memory cells is presented. But the voltage regulator does not include a pull-up transistor. And it does not have an output to turn on the pulldown transistor in the complementary pair upon the regulated voltage exceeding a predetermined value.
Abstract: A voltage regulator for electrically programmable non-volatile memory cells includes a gain stage which is supplied a voltage from a voltage booster connected to a supply voltage reference, having an input terminal connected to an output of a voltage divider and an output terminal connected to a pull-up transistor of a pull-up and pull-down differential pair to output the regulated voltage for programming at least one column or bit line of the memory cells. The voltage regulator also includes a second gain stage having an input terminal connected to a second output of the voltage divider. The second stage has an output connected to turn on the pull-down transistor in the complementary pair upon the regulated voltage exceeding a predetermined value.

Proceedings ArticleDOI
K. Sawada1, Y. Sugawara1, S. Masui1
08 Jun 1995
TL;DR: In this paper, an on-chip high-voltage generator circuit for lowvoltage EEPROMs composed of a pMOSFET-based charge pump circuit driven by bootstrapped clock generators is proposed.
Abstract: We propose an on-chip high-voltage generator circuit for low-voltage EEPROMs composed of a pMOSFET-based charge pump circuit driven by bootstrapped clock generators. The voltage gain per unit stage does not suffer from the threshold voltage drop. The device implemented in a 1.2 /spl mu/m CMOS technology operates as low as 1 V.

Patent
22 May 1995
TL;DR: In this paper, a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems is presented.
Abstract: A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

Patent
24 Mar 1995
TL;DR: In this article, the authors describe the integration of high voltage circuit elements with low voltage and high density transistors all formed by the same fabrication process sequence, which allows the creation of an 18 volt range charge pump using a CMOS process which normally provides only 3 volt operating range transistors.
Abstract: An integrated circuit includes an N isolation buried layer underlying high density and low voltage type P channel and N channel transistors to define islands of arbitrary voltage on the substrate. Thus such transistors, which otherwise are capable only of low voltage operation, become capable of operating at high voltage relative to the substrate. This allows integration, on a single chip, of high voltage circuit elements with low voltage and high density transistors all formed by the same fabrication process sequence. In one example this allows creation of an 18 volts range charge pump using a CMOS process which normally provides only 3 volt operating range transistors. This then allows integration on a single integrated circuit chip of a complex digital logic function such as a UART (universal asynchronous receiver and transmitter) with a high voltage function such as an RS-232 interface, including integrated capacitors for the RS-232 interface charge pump.

Patent
Harri Jokinen1
08 Jun 1995
TL;DR: In this paper, the authors proposed a method to reduce the power consumption of an electronic device comprising at least one voltage regulator by switching off and on according to a predetermined duty cycle during such periods when the electronic device does not require the normal power supply ability of the regulator.
Abstract: The invention relates to a method to reduce the power consumption of an electronic device comprising at least one voltage regulator. At least one of the regulators (REG1 - REG4) is switched off and on according to a predetermined duty cycle during such periods when the electronic device does not require the normal power supply ability of the regulator. This may be realized e.g. in a mobile phone during two successive control channel messages received from a base station when the mobile phone is in a so called power saving mode.

Patent
Kyung-Sang Lee1
14 Jul 1995
TL;DR: In this paper, a power-supply controller of a computer can minimize power-consumption as shown in the following description, which is composed of a power supply, a power controller, and a powermode controller.
Abstract: The power-supply controller of a computer can minimize power-consumption as shown in the following description. The operation mode will convert to a sleep-mode reducing the power-consumption below a constant voltage if there is no input to operate a computer system for a predetermined period of time. If the condition of no input for operating a computer system persists, the power supply controller cuts off the power-supply once again. In order to achieve this object, this invention is composed of a power-supply, a power-controller, and a power-mode-controller. The power-supply includes a first rectifier that converts an AC voltage to a DC voltage, a DC/AC converter which converts a DC voltage into an AC voltage, a switching mechanism which outputs a pulse signal used to operate the DC/AC converter, a second rectifier which converts to a DC voltage from an AC voltage received from the DC/AC converter, and a driver which provides an operation voltage to operate the switching mechanism. The power-controller outputs a power-supply signal used to change from the sleep-mode into a power-off mode if there is no input for a predetermined period during the sleep-mode, and which outputs a power-supply signal to change from the power-off mode into a resume-mode if there is an input. The power-mode-controller also includes a power-mode control circuit that varies the output from the power-controller and varies an operation voltage to operate the switching mechanism and a charger which charges a battery with AC voltage and provides the power-controller with a power-supply.

Patent
20 Oct 1995
TL;DR: In this paper, an overvoltage detection and clamping circuit monitors the applied voltage for extreme voltage excursions, and if an over voltage threshold is exceeded for two successive cycles, the applied power is interrupted.
Abstract: A dc sputtering process applies a pulsating dc voltage in which each cycle includes a pulse portion of negative dc voltage of -300 to -700 volts alternating with a reverse bias (positive) pulse of about +50 to +300 volts The reverse bias pulse portion will reduce or eliminate sources for arcing in most cases To combat sticky or persistent arcing, the negative pulse portion is monitored If, during a window portion of the negative pulse portion, the applied voltage drops into a range characteristic of arcing for two successive cycles, then the applied power is interrupted for a period, eg, 200 microseconds, and reverse bias is applied An overvoltage detection and clamping circuit monitors the applied voltage for extreme voltage excursions, and if an overvoltage threshold is exceeded for two successive cycles, the applied power is interrupted The overvoltage detection and clamping circuit can comprise a string of zener diodes or equivalent voltage limiting devices connected to the applied voltage This circuit absorbs the voltage excursions beyond the threshold and protects the power supply and the substrate in the plasma chamber

Patent
24 Jan 1995
TL;DR: In this article, a determinate power source control for an integrated circuit (10) includes a variable voltage regulator (16), which is operable to receive a supply voltage on the input thereof and output a regulated voltage for input to the integrated circuit.
Abstract: A determinate power source control for an integrated circuit (10) includes a variable voltage regulator (16), which is operable to receive a supply voltage on the input thereof and output a regulated voltage for input to the integrated circuit (10). A voltage adjustment circuit (22) is operable to generate a voltage adjustment value V ADJ for input to the voltage regulator (16) to determine the voltage output thereby. In a determinate operating mode, the voltage adjustment circuit (22) varies the V ADJ value to cause the regulator (16) to vary the regulated output voltage to the integrated circuit (10). For each value, the operating speed of the integrated circuit (10) is determined and this information stored in a table (24). Thereafter, the voltage adjustment circuit (22) is placed in an operating mode wherein the voltage adjustment value associated with the optimum operating speeds of the integrated circuit (10) is selected and input to the voltage regulator (16). The voltage adjustment circuit (22) utilizes an on-chip ring oscillator (38) to generate a series of pulses which are input to a counter (48). The counter (48) and ring oscillator (38) are operated for a predetermined amount of time with reference to crystal oscillator (30), and then this value latched into latch (52).

Patent
26 Apr 1995
TL;DR: In this article, an electronic ballast includes a converter coupled to a variable frequency inverter and a series resonant, parallel loaded output coupled to the inverter, and the amount of boost, and therefore the magnitude of the supply voltage, is varied to provide dimming.
Abstract: An electronic ballast includes a converter coupled to a variable frequency inverter and a series resonant, parallel loaded output coupled to the inverter. The frequency of the inverter increases when the supply voltage from the converter decreases. The converter includes a full wave rectifier (17) producing a first voltage and an unregulated boost circuit (Q1, Q2) producing a second voltage which is combined with the first voltage to produce the supply voltage. The amount of boost, and therefore the magnitude of the supply voltage, is varied to provide dimming. Dimming is controlled mechanically, via a potentiometer (126), or electrically, via a control input (132). Dimming also occurs in response to changes in the first voltage, i.e. from changes in the voltage on an AC power line or from changes in the voltage provided by a capacitive dimmer coupled between the ballast and an AC power line.

Patent
06 Jun 1995
TL;DR: In this paper, a charge pump for increasing the value of an input voltage includes a plurality of serially coupled charge pump stages, wherein each charge pump stage includes a P-channel pass transistor coupled to a first end of a capacitor.
Abstract: A charge pump for increasing the value of an input voltage includes a plurality of serially coupled charge pump stages, wherein each charge pump stage includes a P-channel pass transistor coupled to a first end of a capacitor. The gates of the P-channel pass transistors and the second ends of the capacitors in odd-numbered charge pump stages receive a first phase clock signal, and the gates of the pass transistors and the second ends of the capacitors in even-numbered charge pump stages receive a second phase clock signal, except that the second end of the capacitor in the last charge pump stage is coupled to ground. To increase the value of the capacitors in an integrated circuit embodiment all of the capacitors, except for the capacitor in the last stage, are ideally ferroelectric capacitors. In a preferred embodiment, the charge pump is one component in a regulated charge pump system that also includes a voltage regulator and a controlled oscillator. In operation, the voltage regulator determines whether the boosted output voltage is greater or less than a predetermined target output voltage and accordingly selectively controls the operation of the oscillator. In turn, the charge pump is enabled to selectively charge pump the input voltage to provide a boosted output voltage if the boosted output voltage is less than a predetermined low target output voltage. Charge pumping is disabled if the boosted output voltage is greater than a predetermined high target output voltage.

Patent
14 Dec 1995
TL;DR: In this article, a solid state inverter is used to inject a series compensation voltage into the transmission line at a controllable magnitude and a phase angle between + or -90 electrical degrees relative to transmission line current.
Abstract: Apparatus (9) for providing reactive compensation and positive real power compensation in an ac electric power transmission system (1), utilizes a solid state inverter (11) to inject a series compensation voltage into the transmission line at a controllable magnitude and a controllable phase angle between + or -90 electrical degrees relative to transmission line current. The positive real power needed by the inverter (11) is drawn from the transmission line (3) by a rectifier (19) shunt connected to the line (3).

Patent
21 Dec 1995
TL;DR: In this article, an amplifier circuit employing automatic gain control (AGC), with the gain responsive to a varying input signal level, and particularly adapted for manufacture as an integrated circuit, is presented.
Abstract: An amplifier circuit employing automatic gain control (AGC), with the gain responsive to a varying input signal level, and particularly adapted for manufacture as an integrated circuit. In a preferred embodiment, an error voltage is produced which is indicative of the difference between the RMS output voltage of the amplifier and a target RMS voltage. A ramp generator generates a ramp voltage in accordance with a digital count generated by a ripple counter. A comparator then produces a control signal in accordance with the difference between the ramp voltage and the error voltage. When the control signal is indicative of the amplifier output voltage differing from the target voltage, the gain is updated in accordance with the digital count and the count and ramp voltage are reset.