Showing papers on "Voltage multiplier published in 1989"

Ac to dc converter with unity power factor

Abstract: An AC to DC converter comprises a bridge rectifier followed by a boost circuit The boost circuit includes an inductor, diode and load capacitor in series and a shunting switch connected to shunt the diode and load capacitor The control circuit for switching the shunting switch comprises a differential circuit, a multiplier and a duty cycle generator in a feedback loop which maintains a constant output voltage on the capacitor To eliminate the response to ripple on the output voltage, the differential circuit does not respond to voltages within a dead band

Analysis and modeling of on-chip high-voltage generator circuits for use in EEPROM circuits

Abstract: Most of the presently available EEPROM circuits feature 5-V-only operation and therefore incorporate on-chip high-voltage generators. In spite of the importance of these latter circuits, a thorough analysis of the circuit has not been presented. In this paper the characteristics of the voltage multiplier circuit are thoroughly analyzed and modeled. The results obtained from this analysis are fully confirmed by experiments. The degradation characteristics of the circuit are discussed and its capability to compensate for nonvolatile memory degradation is shown. >

Hand held high power pulsed precision x-ray source

Abstract: A pulsed precision x-ray source includes a miniaturized internally self-shielding x-ray tube and an integral generator contained in a hand-held housing for generating timed bursts of x-ray having regulated energy level. A control grid and focus electrode within the tube enable precise on-off control of an electron beam directed to an x-ray emitting anode. The integral generator system includes an elongated, U-shaped unitary, molded plastic block mounted in the housing and includes a high voltage transformer having primary and secondary annular windings encased in a transformer portion of the block defining a central opening outside of the block for receiving a transformer core therethrough and, a capacitor-diode voltage multiplier stack connected to the secondary winding and having a positive node connectable to the anode and a negative node connectable to the cathode. A high voltage pulse width modulated switching circuit is connected to the primary annular winding to generate high voltages across said voltage multipler stack in order to control the energy of x-ray put out by the tube. A heater power supply supplies heater current to operate a heater in the tube. A focus element/grid control voltage power supply generates control voltages. A control circuit controls application of the control voltages to the focus element and the grid in order to switch the electron beam on and off in accordance with a preset value.

Voltage Compensation of an Induction Generator with Long-Shunt Connection

Abstract: Preliminary studies of voltage vs. speed relationships, stability of generated voltage, and voltage compensation of the self-excited induction generator are presented. In order to improve the voltage regulation, the long-shunt connection of the capacitors to the generator is used. The magnetizing inductance of the machine is used as a saturable reactor. The values of the capacitors for series and parallel connections are obtained from the saturation characteristics of the machine. Experimental results are reported. The maximum voltage drop is about 4%. >

Dual mode actuator for disk drive useful with a portable computer

Abstract: A portable computer having an associated disk drive includes a voltage multiplier coupled between a microprocessor and a head positioning actuator that operates in two modes. In a moderate performance mode, the dual mode actuator operates with the power supplied by a storage battery or by a commercial power source with the voltage multiplier turned off. In a high performance mode, the voltage multiplier under control of the microprocessor boosts the voltage supplied to the actuator so that more power is made available for fast head positioning and job execution with an improvement in computer performance.

Regulation of the output voltage of a voltage multiplier

Abstract: The regulation of the output voltage of a voltage multiplier driven by a ring oscillator, an inverter of which is substituted by a NOR gate for providing a terminal through which stopping the oscillation, is effected by controlling the oscillation frequency in function of the current delivered by the voltage multiplier by means of a transistor T1 working as a current generator connected in series with a regulating chain of series-connected diodes by biasing the gate of the transistor with a constant voltage Vref, thus imposing a reference current Iref through the transistor. The voltage signal across the transistor is fed to the input of a first inverter with a preset triggering threshold and the output signal of the inverter is fed through an amplifying and phase-regenerating stage to said terminal for stopping the oscillation of said NOR gate of the ring oscillator. When the discharge current through the regulating chain becomes greater than the imposed current Iref, across the transistor T1 a voltage signal develops which, beyond a certain threshold, determines the switching of the inverter and, through the amplifying and phase-regenerating stage, causes a stop of the oscillation which resumes only when conduction through the regulating chain stops. At steady state the oscillation frequency will result controlled so as to maintain constant the output voltage of the voltage multiplier and to limit the discharge current through the regulating chain thus limiting power consumption.

Voltage multiplier for nonvolatile semiconductor memory

Abstract: A voltage multiplier for a use in a non-volatile semiconductor memory and operated at a low operation voltage with a reduced area comprising a plurality of cascade-connected basic circuits.

X-ray tube apparatus with protective resistors

Abstract: An alternating-current voltage of a commercial power supply is converted to a direct-current voltage by a rectifier and the output direct-current voltage of the rectifier is converted to an alternating-current voltage again by a DC/AC inverter. The alternating-current voltage is boosted by a transformer up to an intermediate voltage (e.g., 1-20 KV). The output voltage of the transformer is supplied through the slip-ring provided between a frame stationary section and a frame rotating section of a voltage multiplier provided within the rotating section to be multiplied to a high voltage (e.g., ±60-±70 KV). Outputs of the voltage multiplier are supplied to the anode and cathode of an X-ray tube. A voltage multiplier for producing an anode supply voltage and a voltage multiplier for producing a cathode supply voltage are constructed in separate units. The two voltage multiplier units and the X-ray tube unit are disposed within a housing of the rotating section shaped like a ring at equal angular intervals of 120°. The X-ray tube unit contains a protective resistor. The protective resistor is connected in at least one of positions between the anode of the X-ray tube and an anode voltage supply terminal, between a center metal of the X-ray tube and a center metal terminal and between the cathode of the X-ray tube and a cathode voltage supply terminal.

CMOS voltage multiplier

Abstract: A wholly integrated, multistage, CMOS voltage multiplier utilizes as a diode structure for transferring electric charge from an input node to an output node of each stage an enhancement type MOS transistor, the gate of which is coupled to the same switching phase to which the output capacitor of the stage is connected by means of a coupling capacitor. During a semicycle of charge transfer through said MOS transistor, the coupling capacitor charges through a second MOS transistor of the same type and having the same threshold of said charge transfer MOS transistor, connected in a diode configuration between the output node of the stage and the gate of the charge transfer MOS transistor, in order to cut-off the latter when reaching a voltage lower than the voltage reached by the output node by a value equal to the threshold value of said second transistor. In this way, a significant voltage drop across the charge transfer transistor is efficiently eliminated, thus allowing the generation of a sufficiently high output voltage though having available a relatively low supply voltage.

Address decoder circuit for non-volatile memory

Abstract: An address decoder circuit adapted for enabling electrical erasure in a non-volatile memory without the necessity of numerically increasing the component elements, wherein the direction of application (polarity) of a supply voltage during an erasing operation to a decoding logic gate portion comprising a load MOS transistor and an address input MOS transistor is rendered different from that during a writing or reading operation, and a third potential is applied to the power terminal proximate to the address input MOS transistor and also to the power terminal of a buffer, whereby the third potential is outputted to prevent erasure in the state of non-selection. The resistance of load means is changed to be greater in a writing operation for reducing the power consumption during the writing operation and minimizing the dimensions of component elements. And in a voltage supply circuit, for the purpose of outputting a desired voltage without providing any additional circuit which may consume great power or without causing any level reduction of a first or write voltage, a MOS transistor for outputting the first voltage is controlled in response to a signal obtained by boosting the voltage of a control signal through a voltage multiplier.

Single phase to three phase rectifier/inverter with DC ripple compensation

Abstract: In a power converter apparatus, variations contained in a single-phase AC input voltage cause a beat phenomenon in a three-phase DC/AC inverter. To avoid such a beat phenomenon, the single-phase AC input voltage is converted into a DC input voltage having ripple components and the ripple components are filtered from the input voltage so as to derive an input DC voltage. The input DC voltage is inserted into a three-phase AC voltage. Variations contained in the single-phase AC input voltage are detected to obtain a variation detecting signal and the inversion is controlled in a pulse width modulation control mode based upon the variation detecting signal and a reference signal.

Magnetron power supply with indirect sensing of magnetron current

Abstract: A magnetron (M) serving as the microwave source in a microwave oven is driven by a Switch Mode Power Supply (SMPS). The resonance circuit of the Power Supply contains a transformer (Tr), the secondary side of which is connected to the magnetron via a voltage multiplier consisting of a rectifier and voltage doubler circuit (C3, C4, D3, D4). In order to obtain a feedback signal which is proportional to the power fed to the magnetron thereby to regulate this power, a current transformer (ST) is connected in series with one of the diodes (D3) in the rectifier and voltage doubler circuit. The output signal of the current transformer is compared in a control circuit (K) with a reference signal and the result of the comparison is used to control the switch frequency and thereby the magnetron power.

Test selection techniques

Abstract: A test selection system is provided which includes a semiconductor substrate having a pin connected thereto and an integrated circuit disposed on the substrate and connected to the pin having an operating voltage within a given voltage range. A latch conditioning circuit having an input responsive to a voltage of a given magnitude has an output connected to a latch, and a voltage control circuit operable at a voltage without the given voltage range selectively applies a control voltage of the given magnitude to the input of the latch conditioning circuit. A voltage without the given voltage range is applied to the pin during a first interval of time to produce the control voltage for establishing a test mode and a voltage within the given voltage range is applied to the pin during a second interval of time to establish a normal operating mode for the integrated circuit.

Integrated voltage multiplier circuit for low supply voltage

Abstract: integrated voltage multiplier circuit for low supply voltage. In order to improve the signal-to-noise ratio in battery-operated switched capacitor filter circuits in hearing aids, the range of modulation can be increased by doubling the supply voltage. A circuit for voltage multiplication in CMOS technology generates a negative voltage for a given voltage. In order to be able to utilize both clock phases, a two-stage embodiment is selected, both of these working onto a smoothing capacitor. The voltage multiplier circuit is driven by a fourth inverter stage and with a level converter having a connected, third inverter stage.

Self-biasing solid-state T/R switch

Abstract: A solid-state switch for coupling an antenna to either a transmitter or a receiver. The switch includes a pair of oppositely poled diodes and a low voltage power supply connected between the diodes for providing a forward biasing voltage to the diodes. Reverse biasing voltage to stop RF current flow through the diodes is provided by the RF signal itself by means of a voltage doubler. The same voltage doubler and a power detector reverse bias the receiver diode during overload conditions.

Structure for providing electrostatic discharge protection

Abstract: In one embodiment, the threshold voltage of the electrostatic protection circuit is selectively raised above the power supply voltage by the inclusion of a plurality of serially connected diodes connected between the power supply voltage and a discharge reference rail. The serially connected diodes become forward biased when a voltage applied to the rail is above the power supply voltage by a voltage equal to the sum of the various voltage drops across the serially connected diodes. The various input pads of the integrated circuit are connected to an anode of an associated diode, wherein the cathode of the associated diode is connected to the discharge reference rail, rather than directly to VDD as in the prior art. The anodes of each of these diodes are also connected to the device to be protected within the integrated circuit. Thus, when a voltage applied to the input pad is approximately one diode drop above the discharge reference rail, the voltage at the input pad will be shunted to the power supply voltage generator through the serially connected diodes.

Control apparatus for an a.c. generator for automobile

Abstract: A reference voltage circuit for a voltage regulator control includes three parallel voltage dividers cross-coupled by oppositely poled diodes, one of the dividers having a negative voltage-temperature characteristic tied to the battery electrolyte temperature and another divider having a positive characteristic. With this arrangement the reference voltage remains constant below a first electrolyte temperature t1, decreases between t1 and a second, higher temperature t2, and decreases at a reduced rate above t2.

Battery-charging system with fault indicator

Abstract: The battery charging system includes a generator, a rectifier system with main diodes and exciter diodes as well as two terminals (B+, D-) for battery charging, at least one terminal (D+) for consuming points, a voltage regulator (14) for a generator output voltage, a charging control light (16) and a fail-safe device (15) structured to indicate faults and for protection from excess voltages. The fail-safe device includes an additional voltage regulating device (17) connected electrically to the generator and a relay (27) connected with the additional voltage regulating device. The fail-safe device also can include three voltage dividers (82, 83, 84; 70,71; 48,49) to provide different adjustable voltage thresholds, four Zener diodes (20 to 23) connected across terminals (D+ and D-) for limiting voltage, a pulse generator and a delay stage (19) structured and connected so that the additional voltage regulating device (17) regulates the generator output voltage, when an excess voltage occurs or a defective connection is present in the voltage regulator.

A power supply arrangement

Abstract: A magnetron (M) serving as microwave source in a microwave oven is driven by a Switch Mode Power Supply (SMPS). The resonance circuit of the Power Supply contains a transformer (Tr), the secondary side of which is connected to the magnetron (M) via a voltage multiplier in the shape of a rectifier and voltage doubler circuit (C3, C4, D3, D4). In order to obtain a feed-back signal, which is a measure of the power fed to the magnetron in order to enable regulation of this power, a current transformer (ST) is connected in series with one of the diodes (D3) in the rectifier and voltage doubler circuit. The output signal of the current transformer (ST) is compared with a reference signal and the result of the comparison is used to control the switch frequency and thereby the power.

Design and analysis of an optical-powered on-chip power supply

Abstract: The design of an optical-powered on-chip power supply is described. This power supply is intended for use with microchips. An NMOS voltage doubler, a CMOS voltage doubler, a CMOS voltage tripler, and a CMOS oscillator have been designed. The design of an n-stage voltage multiplier is proposed and simulated. The optical powered on-chip power supply consists of a CMOS voltage tripler and a CMOS oscillator used as a clock. Simplicity has been emphasized in the design. The static power dissipation for an NMOS transistor design is much more than that of a CMOS transistor design. The NMOS design performance deteriorates under load conditions. The CMOS design has very minimal static power consumption. Because of this, the CMOS design is superior to the NMOS design. This power supply can deliver power of about 25 mu W with a regulation of about 10% using on-chip capacitors. Higher power operation is obtained using external capacitors. Standard 3-micron CMOS MOSIS (MOS Implementation Service) design rules have been used for the design and simulation of the circuit. The representative chip area allocated to a 25 mu W source is 0.25 mm/sup 2/. The whole circuit is simulated by using UC Berkeley SPICE2G.5/6. >

Amplitude variable pulse generating circuit

Abstract: An amplitude variable pulse generator is provided with two voltage supply sources. The first voltage source supplies a variable voltage which determines the amplitude of the output pulse. The second voltage source is a fixed or constant voltage source which provides a voltage lower in value than the first voltage. The second voltage source quickly pulls up a voltage between a drain and a source of a switching MOSFET, which generates the output pulse, by providing a charging voltage for an output capacitance of the MOSFET. By doing so, the output capacitance of the MOSFET is quickly reduced, and the trailing edge of the output pulse is not rounded even when the variable voltage is low. As a result, the waveform of the output pulse is not rounded for a very small amplitude pulse. Resolution of a supersonic wave device especially a supersonic diagnostic device is thereby improved.

Constant voltage/constant frequency power supply equipment

Abstract: PURPOSE: To make high pressureproof nonstandard components unnecessary by connecting one of AC power input parts between rectifying elements of a converter circuit to convert AC power input DC voltage and by smoothing said DC voltage through a smoothing capacitor to convert said voltage into AC voltage through an inverter circuit. CONSTITUTION: As diodes 1 are connected in series in the same direction, a current can be rectified. A DC voltage obtained in this manner is smoothed by a smoothing circuit B so that a DC voltage with a ripple component of less than several % is obtained. When an input voltage is positive, a switching circuit 6 is turned ON to control the positive half cycle of output voltage. When the input voltage is negative, said switching circuit 6 is turned ON to control the negative half cycle of said output voltage. Said DC voltage is converted into an AC power with specified voltage and frequency by an inverter circuit C. COPYRIGHT: (C)1990,JPO&Japio

Transformer with channels in bobbin

Abstract: Improvement for power supplies include a protection circuit having a first L-C filter network, a second L-C filter network and a voltage clamping device such as a zener diode which is disposed between the two L-C filter networks. The protection circuit reduces the magnitude of overvoltage input transients which might otherwise damage the internal components of the inverter. For generating very high output voltages, the power supply includes a high voltage transformer and a Crockoft-Walton voltage multiplier coupled thereto. The high voltage transformer is coupled to an inverter through a coupling circuit which includes a capacitor in one leg of the primary winding and a parallel connected resistor/inductor in the other leg of the primary winding of the high voltage transformer. The high voltage transformer is formed of a multi-sectioned bobbin which is defined around an axially extending core. A first insulating tape formed of a material having good insulation resistance and a relatively low dielectric constant is wound in the channel and the secondary winding is then wound around the insulation, substantially filling the bobbin. Thereafter a second similar insulation is wound around the secondary winding and the primary winding is wound over the second insulation.

Integrated voltage multiplier for a low-voltage supply

Abstract: An integrated voltage multiplier for a particularly low feed voltage (1.5V) is described. The voltage multiplier is mainly used in electrically erasable and programmable read-only memories (EEPROMs) for generating the programming voltage (Vpp). The voltage multiplier contains an arbitrary number of multiplier stages (i) with a pumping capacitor (Ci). During a first clock phase, the pumping capacitor (Ci) is charged up to the primary feed voltage (Vdd - Vss) by means of a first transistor (Pi) of the PMOS type and a second transistor (Ni) of the NMOS type. During a second clock phase, the pumping capacitor (Ci) is switched by means of a third transistor (Si) of the NMOS type in series with the pumping capacitor (Ci + 1) of the subsequent multiplier stage (i + 1).

Arrangement for producing a high voltage which is adjustable in steps

Abstract: The arrangement for producing a high voltage which is adjustable in steps contains a plurality of DC voltage sources which can be switched on and off and are connected in series on the output side via a diode cascade, and whose output voltages can in each case be adjusted in steps, independently of one another, between a predetermined minimum value and a predetermined maximum value. The DC voltage sources each contain a voltage multiplier arrangement as invented by Greinach.

Ripple insensitivity method for regulating the voltage of a voltage signal

Abstract: A direct-current high voltage obtained by rippling, stepping-up and rectification of a direct-current low voltage is regulated in such a manner as to ensure that the maximum value of direct-current high voltage attains a predetermined peak value at each ripple pulse of the inverter. To this end, a following pulse of the inverter is produced as soon as the high voltage of the direct-current high-voltage signal has become lower than the predetermined peak value reduced by the measurement of a variation in said direct-current high voltage during a preceding pulse.

Integrated-voltage multiplier circuit for a low-voltage power supply

Abstract: Um bei batteriebetriebenen SC-Filterschaltungen in Horgeraten das Signal/Rauschleistungsverhaltnis zu verbessern, kann man den Aussteuerbereich dadurch erhohen, indem man die Versor gungsspannung verdoppelt. In order to improve the signal / noise ratio in battery-powered SC filter circuits in hearing aids, one can thus increase the dynamic range by doubling the versor supply voltage. Es wird eine Schaltung zur Spannungs vervielfachung in CMOS-Technologie angegeben, welche zu einer gegebenen Spannung eine negative Spannung erzeugt. It is a circuit for voltage multiplication in CMOS technology indicated that generated at a given voltage, a negative voltage. Um beide Taktphasen ausnutzen zu konnen, wird eine zweistufige Aus fuhrung (ST1, ST2) gewahlt, die beide auf eine Glattungs kapazitat (C3) arbeiten. To use both clock phases exploit is a two-stage imple mentation (ST1, ST2) is selected, both of which operate on a smoothing capacity (C3). Angesteuert wird die Spannungsver vielfachungsschaltung mit Hilfe einer vierten Inverterstufe (I4) und einem Pegelumsetzer (PU) mit einer angeschlossenen dritten Inverterstufe (I3). The Spannungsver is controlled vielfachungsschaltung using a fourth inverter stage (I4) and a level converter (PU) with a connected third inverter stage (I3).

Liquid crystal display having clock-controlled disconnection

Abstract: Liquid crystal displays are driven by a driver circuit, usually using a multiplex method. For generating the driver signals a multiplicity of different voltage levels is necessary which are generated by voltage multiplier circuits. The driver circuit and the voltage multiplier circuit are connected to a clock generator to ensure, inter alia, a regular polarity change-over at the electrodes of the liquid crystal display. To protect the liquid crystals from being loaded with a direct current, for example in the case of a failure of the clock generator, according to the invention there is provided a means which switches off the driver stage when the difference between the basis voltage level and a voltage level generated by the voltage multiplier circuit falls below a predetermined value.