Showing papers on "Voltage multiplier published in 1988"

Compensated exponential voltage multiplier for electroluminescent displays

Abstract: An exponential multiplication power supply is described which is comprised of a plurality of stages each having the ability to store energy and each having a plurality of states, including at least a store state and a stack state The plurality of stages are arranged in a network such that an input stage in the network is connected to receive a voltage from an external power source and all subsequent stages are connected to at least one other stage for receiving voltage from and through the other stages A control mechanism is attached to the network stages and operates to place these stages in a repeating sequence of states such that at least one of the stages receives a voltage which is the sum of the voltages stored in at least two other stages When a stage is receiving voltage or holding voltage it is said to be in the store state, and when a stage is combined with other stages to present an increased voltage, it is said to be placed in the stack state This exponential voltage multiplication power supply is applied to the production of high voltage for exciting electroluminescent panels The application of this power supply includes compensation circuitry to vary the excitation in response to varying characteristics of the electroluminescent panel

Ignition device for a gas discharge lamp

Abstract: The invention provides an ignition device for a gas discharge lamp. The device comprises a voltage multiplier which is connected to an AC mains source. A pulse generator is connected to the voltage multiplier and produces a trigger pulse when the source voltage exceeds a predetermined threshold. The output of the pulse generator is applied to a resonant network including a step-up transformer, which applies high voltage ignition pulses to the lamp. A delay circuit synchronizes the ignition pulses with the peaks of the AC mains waveform.

Integrated poly-phase power meter

Abstract: A high accuracy power meter capable of mea­suring power supplied or consumed in multiple phases of a distribution system is fabricated as an integrated circuit. Voltage and current sensing transducers coupled to the power meter provide input signals having a potential proportional to the voltage and current in the distribution system. A low charge injection pulse width amplitude multiplier using a digitally-synthesized triangular wave is provided for each phase. Each multiplier receives the input signals and provides an output signal having a current proportional to the product of voltage and current in that phase of the distribution system. Charge from the multiplier output currents for all phases is accumulated in a capacitor connected across an autozeroing amplifier, which corrects for its own offset voltage. The amplifier output controls a switch connected between a reference potential and the capacitor. When the switch is closed a reference current is supplied to the accumulating capacitor to balance the charge from the multiplier for each phase. The frequency of the switch control signal provides a highly accurate measure of the power consumed or supplied by the distribution system.

Low input voltage resonant power converter with high-voltage A.C. link

Abstract: A high-frequency resonant power converter transforms a relatively low D.C. input voltage to a relatively high A.C. link voltage to drive a resonant circuit. The high A.C. voltage appearing across a resonance circuit high-voltage capacitor is then transformed down to a relatively low value and rectified to obtain a desired relatively low D.C. output voltage. Use of a high A.C. link voltage eliminates low voltage operation of the resonance circuit, which would require very large resonant capacitors having high current ratings. Composite magnetic structures which combine a resonant inductor and a transformer are also disclosed.

AC rectifier circuit with means for limiting the rectified voltage

Abstract: The invention relates to an AC voltage supplied rectifier circuit with a downstream smoothing capacitor. A prior art problem with this type of circuit was that the inductive impedance of the supply voltage caused a practically umdamped oscillation between the inductive supply impedance and the smoothing capacitor during start-up which caused the voltage to rise to about twice the stationary value. A rectifier circuit is provided which substantially prevents the over-oscillation having at least one controllable rectifier which brings the rectifier to a conductive state during the charging period of the smoothing capacitor over such a time that the output direct voltage of the rectifier circuit exceeds the momentary capacitor voltage by no more than a predetermined limited value.

High voltage DC power supply

Abstract: A DC power supply for a traveling wave tube having cathode, collector and helix electrodes responds to a DC power source and a high frequency switching source. A switch controlled by the switching source is opened and closed at a fixed frequency and variable duty cycle determined by the helix-cathode voltage. A flyback choke is connected to the switch and DC power supply so current flows between the power source via the choke to the switch and a series resonant circuit while the switch is closed. First and second capacitors in separate branch circuits of the resonant circuit are respectively connected to first and second AC to DC converter and voltage multiplier stacks; each multiplier in the stacks includes a pair of branches with oppositely poled plural signal switching diodes and a capacitor. The cathode and helix are respectively connected to output terminals of the first and second stacks, while the collector is connected to a terminal between the first and second stacks. The resonant circuit is connected with the switch, flyback choke and voltage multipliers so that while the switch is closed a half-wave rectified current waveform at the resonant circuit resonant frequency flows in the resonant circuit and a ramping current having a first polarity direction flows in the choke. A ramping current having a second plurality direction flows in the choke and resonant circuit while the switch is open.

Automotive alternator power generator for welding or use of power tools

Abstract: An electrical power supply used on a motor vehicle is interconnected with the vehicle battery, alternator and regulator. The power supply includes a voltage multiplier for multiplying the rectified output voltage from the alternator, and welding sockets for facilitating a welding operation. A multi-pole switch exclusively selects the operating mode of the power supply from among normal battery charging, power appliance operation and welding.

Voltage multiplier circuit and rectifier element

Abstract: The invention relates to a voltage multiplier, comprising a series connection of rectifier elements which are alternately rendered conductive by alternately applying complementary clock signals to capacitances which are connected to junction points of pairs of neighbouring elements. The rectifier element is constructed by means of field effect transistors so that the well in the substrate in which the element is realized receives either the anode voltage or the cathode voltage. This prevents the occurrence of the so-called back-gate bias effect which increases the threshold voltage of the element and limits the output voltage of the voltage multiplier.

Voltage detection circuit and comparison voltage generator therefor

Abstract: In a voltage detection circuit, a comparison voltage generator includes reference-setting capacitors, each having a first terminal connected to a comparison voltage node, and switching circuits provided in association with the respective reference-setting capacitors, each switching circuit selectively connecting a second terminal of the associated reference setting capacitor either to a first potential node or to a second potential node.

Voltage multiplier circuit with reduced back-gate bias effect

Abstract: A voltage multiplier includes a series connection of rectifier elements which are alternately rendered conductive by alternately applying complementary clock signals to capacitances which are connected to junction points of pairs of neighboring rectifier elements. The rectifier element is constructed by means of field effect transistors so that the well in the substrate in which the rectifier element is formed receives either the anode voltage or the cathode voltage. This prevents the occurrence of the so-called back-gate bias effect which increases the threshold voltage of the rectifier element and limits the output voltage of the voltage multipler.

Load control system

Abstract: A load control system (10) generates a periodic failsafe signal (CO) and two control signals. The failsafe signal (CO) is used to drive a charge (20) pump which acts as a voltage multiplier to generate an enable signal. A DC bridge circuit (30) includes four n-channel MOSFETs (Q1-Q4), and the load control signals are used to close respective diagonally opposed pairs of the MOSFETs to apply voltage to a load. The load control signals also isolate selected switch drivers (K1-K4) from a power supply in order to prevent shorting of the bridge (30). The enable signal generated by the charge pump (20) is applied to two of the MOSFETs, and voltages are selected such that the MOSFETs will not close unless the enable signal is at a sufficiently high level to indicate proper oscillation of the failsafe signal (CO).

Isolated analog voltage sense circuit

Abstract: An improved isolated analog voltage sensing circuit which has isolated windings (102A, 102B) of a transformer (102). Sensor means (106, 256) sense the input voltage and apply this to the input winding (102A) of the transformer. A capacitor (116) is connected to the output winding (102B) of the transformer via switching means (110), so coupling the capacitor to the input voltage. An oscillating clock signal (122) controls switching means (110) to repeatedly connect and disconnect the capacitor to the output winding, whereby the capacitor will charge or discharge during the period that the switching means are conductive so that the voltage of the charge on the capacitor progressively moves at each cycle of the clock means towards a figure matching the input voltage sensed by the sensing means, the output voltage of the capacitor therefore providing a voltage which follows the input voltage but is isolated therefrom.

Programmable analog voltage multiplier circuit means

Abstract: An improved programmable analog voltage multiplier circuit means (PAVMCM) cluding various embodiments thereof that are operable in linear/nonlinear fashion. The PAVMCM is generally made up of multiplier circuit means, at least one switch means and at least one capacitor means. The switch means is connected to a programmable analog voltage (PAV) input and the capacitor means. The circuit means is composed of a high impedance analog voltage (HIAV) programming input, an analog voltage input and current source output means. The capacitor means is connected to the switch means and the HIAV programming input. The capacitor means receives and dynamically stores a PAV input when the switch is closed and then applies the dynamically stored PAV input to the HIAV programming input of the circuit means when the switch is opened. The product of the PAV input and the analog voltage input for a circuit means provides the multiplied current output of the output means thereof. Because of the high impedance of a FET gate means, it may be used where its gate means is the programming input of the PAVMCM means. PAVMCM means can be formed using FET multiplier and differential amplifier multiplier circuit means. The PAVMCM can be arranged to form embodiments of analog vector-vector and analog vector-matrix multiplier circuit means. One of the advantages of the PAVMCM when configured as a vector-matrix multiplier circuit means is that it is useful in an artificial neural network as well as for pattern recognition.

A single D-FET 4-QAM with SC technology

Abstract: A four-quadrant analog multiplier is described that realizes the multiplication of two signals using the triode-region characteristics of a depletion field-effect transistor (D-FET). The design uses only a single D-FET and associated switched-capacitor circuits. As a result, not only has a simple structure been obtained but also the requirement for matching of the D-FETs (which is inherently imposed on this type of multiplier using multiple D-FETs) is completely removed. By adjusting the width of the clock pulse, it is possible to eliminate the error introduced by mismatching between the capacitances inside the multiplier. A four-quadrant analog multiplier (4-QAM) constructed to verify the operating qualities described is reported to have good characteristics. >

Multiple-mode voltage converter

Abstract: A voltage converter (100) converts a high voltage, low frequency input to a low D.C. voltage output. The input is rectified to facilitate the operation of an oscillator (202) which operates alternately a pair of MOSFETS (124 and 126). Upon operation of MOSFET (124), the intermediate D.C. voltage is applied across and directs current in one direction through a primary winding (132) of a high frequency step-down transformer (134) and also charges a series-connected capacitor (152). Upon operation of MOSFET (126), capacitor (152) discharges to provide current through primary winding (132) in the opposite direction. In this manner, an alternating voltage at a high frequency is stepped down to a secondary winding (142) of transformer (134) and is rectified to provide the low D.C. voltage output. Diodes (120 and 122) prevent undesirable oscillations within voltage converter (100) if a short should occur in any load connected to the output of the converter.

Voltage supply for proximity switches

Abstract: An electronic proximity switch exhibits at the output an electronic switch (T1) switching a load (L). A voltage regulator (2) supplies a regulated voltage (Up) via a storage capacitor (C1). When the electronic switch (T1) is switched through, there is no unregulated supply voltage present at the voltage regulator (2) and the storage capacitor (C1) discharges via the connected proximity indicator (1). The decreasing voltage is compared with a reference voltage (Uref) via a comparator (K1) and when it drops below the reference voltage, the output of the electronic switch (T1) and a further switch (T3) are opened so that the voltage regulator (2) is connected to a voltage and rapidly charges the storage capacitor (C1) via a low-impedance branch.

Cmos reference voltage generator device

Abstract: of EP0282725The reference voltage generator device implemented in CMOS technology, comprises a first circuit (10) for generating a differential voltage; a second circuit (12) for amplifying and shifting the differential voltage to provide a single ended voltage; and a third circuit (14) for selectively removing unwanted components from said single ended voltage and to provide a reference voltage that is supply and temperature independent.

High efficiency flasher

Abstract: A heavy duty flasher for incandescent lamps for a motor coach or the like incorporates a pair of power MOSFETs in parallel for efficient, cool operation and includes a pair of timers, one for flash rate control and the other for producing AC for operating a voltage multiplier to provide gate voltage for the MOSFETs. Protective circuitry senses current overload and terminates current flow to protect the power devices while allowing inrush current to the lamps at the beginning of each cycle. A circuit sensitive to the presence of load supplies power to the timers only under load conditions.

Switched mode power supply with start-up control

Abstract: In a switched mode power supply, an output switch is coupled to the primary winding of a transformer and to an input supply voltage derived from the AC mains voltage. A driver stage is coupled to the output switch and to a switched control voltage for producing on-off switching of the output switch between conduction and cutoff to generate a pulse voltage in a secondary winding of the transformer. A supply circuit including a rectifier is coupled to the pulse voltage for generating an operating voltage. A control circuit, responsive to the feedback of the output voltage, modulates the control voltage in a manner that varies the on-off switching of the output switch to stabilize the operating voltage. A bias voltage, derived from the AC mains voltage, and available during a startup interval of the power supply, is coupled to the driver stage during the startup interval. The bias voltage inhibits conduction of the output switch until sufficient time has elapsed after initiation of startup to enable the control circuit to generate a control voltage that is adequate to safely produce the on-off switching of the output switch.

Mains converter for a multi-system, multiple-unit train

Abstract: It is intended to specify a circuit arrangement for a mains converter of a DC voltage intermediate circuit converter on a multiple-unit train, which mains converter can optionally be connected to an AC voltage network or to one of two DC voltage networks of different voltage amplitude, by means of which circuit arrangement as few semiconductor switches (especially GTO thyristors) as possible are used in an optimum manner for different types of voltage. To this end, two bridge circuits (which operate as four-quadrant controllers during AC voltage operation and consist of in each case four semiconductor switches (T1 to T4 and T11 to T14) which can be switched off) are connected in series with freewheeling diodes (D1 to D4 and D11 to D14), which are in each case connected in reverse parallel, with their AC voltage connections being isolated, are connected to the higher mains DC voltage and are operated as two-quadrant controllers. In the case when the supply is provided from the lower mains DC voltage, the arrangement can be switched over to a step-up controller.

Voltage multiplier circuit

Abstract: An EEPROM includes a voltage multiplier (100) for generating an erase voltage and a voltage regulator circuit (108) for controlling the magnitude of the erase voltage. The voltage regulator circuit includes means for providing a first voltage proportional to the erase voltage, means for providing a reference voltage on a reference voltage lead, and means for controlling the voltage multiplier circuit so that if the first voltage is less than the reference voltage, the voltage multiplier circuit will increase the erase voltage, but if the first voltage is greater than the reference voltage, the voltage multiplier will not continue to increase the erase voltage. The voltage multiplier (100) includes capacitors (103) and transistors (101;105) constructed using standard EEPROM processing to withstand high voltages without breaking down.

DC voltage converter operating on the principle of a single-ended forward converter

Abstract: A DC voltage converter operating on the principle of a single-ended forward converter is supplied from a DC voltage source (14) via a switch (12) in pulse-controlled manner. The energy stored in a transformer (8) during the conducting phase of the switch (12) is used for charging a capacitor (32) via a diode (30) in the blocking phase. The discharging of the capacitor (32) is controlled by a regulation device (34) in such a way that the voltage between a terminal (38) of the switch (12) and the comparatively higher-potential terminal (36) of the capacitor (32) remains below a target value (Us) defined by the blocking voltage of the switch (12). In one embodiment, the target value (Us) varies as a function of the voltage (Ue) of the DC voltage source (14). In this way, the input voltage range is increased and the total power loss of the DC voltage converter is reduced.

Semiconductor integrated circuits

Abstract: A semiconductor integrated circuit, comprises a semiconductor integrated circuit chip; a standard voltage generating means for generating standard voltage other than a supply voltage and a ground voltage, at least one, standard voltage wire for supplying the standard voltage to at least one circuit of said semiconductor integrated circuit chip; at least one first capacitor extending along the standard voltage wire, the first capacitor having the standard voltage wire as one electrode thereof, and the other electrode connected to the supply voltage; and at least one second capacitor extending along the standard voltage wire, the second capacitor having the standard voltage wire as one electrode thereof, and the other electrode connected to the ground voltage.

Voltage multiplier compatible with a self-isolated C/DMOS process

Abstract: A CMOS structure is employed to create an isolated large area power output transistor along with a voltage multiplier that acts to develop an overdrive bias in response to clock pulses. The circuit can be employed to couple a relatively low power supply voltage to an output terminal while encountering a small voltage drop across the power transistor.

Device for voltage testing

Abstract: A voltage tester, particularly for relatively low voltage A.C., comprises a device having a contact for electrical connection to an electrical component, and a con­tact that may be touched by an operator through whom capaci­tive connection may be made to earth. The device includes liquid crystal displays powered by the voltage under test via a voltage multiplier.

Current/voltage analysis of SC networks

Abstract: The current/voltage analysis of switched-capacitor networks is presented. The approach is a simple and more general alternative to the existing charge/voltage analysis. Switched capacitor networks are analyzed, using the rules of classical network theory. The pulse impedance of a switched capacitor is obtained and the impedance concept is retained. Synthesis of the pulse impedance using classical network methods is accomplished. The discrete voltage transfer function is derived from the switched-capacitor network. This follows the pattern of electrical network theory and leads to design and realization of digital filters. >

Circuit arrangement for limiting current when inserting a subassembly (module)

Abstract: A circuit arrangement is given for limiting the current surge which is caused, when a subassembly is inserted into a device which is in use, by the action of uncharged capacitors (CL) of the subassembly and can lead to (voltage) dips in the device. According to the invention, an n-channel MOSFET of the enhancement type (FT) is provided in the main current path of the subassembly, the control junction of which transistor is subjected to a slowly increasing control voltage. The effect of the control voltage is that the switching junction of the MOSFET is brought from the non-conducting state into the low-resistance conducting state according to a predetermined time function. The control voltage, which must be higher than the voltage (+UB) to be switched, is generated using an AC generator (T1, RG, CG) and a rectifier circuit (GS), having voltage doubler or voltage multiplier function, which is connected downstream.

High voltage generating device

Abstract: PURPOSE:To stabilize output voltage, by adding pulse induced to a tertiary coil, to the low tension side of a high tension coil, after the pulse is voltage- multiplied according to the change of high tension output voltage due to the change of high tension output current. CONSTITUTION:The fly-back transformer 21 of the co-axial multilayer winding type of a high tension generator is composed of a low tension coil 4, a high tension coil 7, a high tension diode 8, and the like, and high tension side output obtained from driving with a horizontal polarization circuit 9 is fed to a cathode-ray tube 17 through a high tension cable 16. So far as the transformer 21 is concerned, the innermost peripheral side of a low tension bobbin is wound up with a tertiary coil 22, and to the coil 22, a BAL signal conducting resistor 23 is earth-connected, and the other end is connected to the high tension coil 7 through an addition controlling circuit 25 and a voltage multiplier circuit 34. As a result, according to the change of high tension output current, the voltage drop component of the high tension output current is contrived to be adding-controlled, and as a whole, the high tension output voltage is turned into that of stabilized characteristic and the regulation is improved.

Voltage sensing devices

Abstract: A capacitive voltage sensing device for use in a power supply (Fig. 1 not shown) in which a pulse-width modulated inverter drives a voltage multiplier by way of a step-up transformer includes a metal ring (28) around an input terminal post (21) of the muitiplier, the capacitance (C1) between the ring (28) and the terminal post (21) forming part of a capacitative voltage divider (C1, C2) in a circuit which develops an overvoltage trip signal for controlling (41) the inverter. The trip threshold is adjusted to compensate for load current variation.