Abstract: A method of bonding a piezoelectric element and an electrode, including the steps of forming a first coating of a material selected from the group consisting of Au, Al, Zn, Cu, and Sn on a bonding surface of the piezoelectric element, and forming a second coating of a material selected from the group consisting of Au, Al, Zn, Cu, and Sn on a bonding surface of the electrode. The combination of the materials of the first and second coatings is preferably Au/Au, Au/Al, Zn/Cu, or Sn/Cu. The method further includes the step of bringing the first and second coatings into close contact with each other and heating them under pressure to form a metallic bond or intermetallic compound between the first and second coatings, thereby bonding the piezoelectric element and the electrode.

Abstract: In a lighting arrangement comprising a low-pressure discharge lamp and a high-frequency ballast for cold-igniting and operating the low-pressure discharge lamp, said low-pressure discharge lamp is equipped with electrodes which each comprise two or more double-spiral tungsten electrode bodies covered with an emitter. The switching performance of the low-pressure discharge lamp is very high.

Abstract: There is provided a vacuum envelope having at least a first substrate, a second substrate opposed to the first substrate with a predetermined distance thereto, and plural spacers positioned between the first and second substrates A ratio &eegr; is defined by S/A, in which A is the internal cross-sectional area of the vacuum envelope in a cross-section parallel to a plane of one substrate opposed to the other substrate and S is the total cross sectional area of the plural spacers on such cross section, and satisfies a relation 0.78%≦&eegr;≦7.8%.

Abstract: A tension mask frame assembly for a color cathode-ray-tube including a frame having four respective sides, two of the sides paralleling each other and having insert receiving brackets for supporting strand termination inserts therein and vertical mask strands welded to said termination inserts. The strands have a plurality of cross-wires extending perpendicular to the strands and attached thereto by a conductive bonding material. The wires and termination inserts are composed of materials having a first coefficient of thermal expansion. The frame and receiving brackets are composed of materials having a second coefficient of thermal expansion. The termination inserts thermally expand and contract independently of the frame and receiving brackets, whereby movement of the strands in the horizontal dimension is controlled by thermal expansion and contraction of the termination inserts and cross-wires.

Abstract: A cathode ray tube includes an electron gun directing electrons towards a faceplate having an electrode biased at screen potential. The electron beam is magnetically deflected to scan across the faceplate to impinge upon phosphors thereon to produce light depicting an image or information. A neck electrode near the tube neck is biased at or below screen potential and a second electrode between the neck electrode and the faceplate is biased at or above screen potential. As a result, the electrons are deflected over a greater total angle than is obtained from the magnetic deflection. A third electrode proximate the faceplate is biased at or below screen potential to direct electrons towards the faceplate, thereby to increase the landing angle of the electrons thereon.

Abstract: The profile lines of plate-like grid electrodes are formed by a first punching step and separation lines of the plate-like grid electrodes are formed by a subsequent punching step. The angle of a crossing portion formed by the profile line and the separation line is set to not less than 70 degrees and not more than 110 degrees. Due to such a constitution, burrs on the plate-like grid electrode which constitutes an electron gun of a color cathode ray tube can be reduced so that the quality of the cathode ray tube can be enhanced and the manufacturing time of the cathode ray tube can be shortened.

Abstract: A display device includes a display screen, a surface of which is provided with an anti-reflection filter having a conducting layer having metallic particles and transparent areas. The conducting layer is provided with a transparent layer. The transparent layer has a thickness smaller than or equal to the thickness of the conducting layer. The display screen is provided with at least one electrically conducting strip having a metal layer and an adhesive layer provided with electrically conducting particles. The electrically conducting strip is in local electrical contact with the metallic particles of the anti-reflection filter via the conducting particles of the adhesive layer.

Abstract: An image forming apparatus includes a first substrate and a second substrate disposed opposite to the first substrate, with fluorescent material being provided on the second substrate. A matrix wiring having a plurality of first wires and a plurality of second wires is provided, with each of the first wires located on the first substrate, and each of the second wires intersecting the plurality of first wires. Also included are electron-emitting devices, each of which emit an electron by applying a signal to the matrix wiring, and a metal electrode, having a plate-shaped form, provided above the matrix wiring, with the metal electrode having electron through-holes for passing electrons emitted by the electron-emitting devices.

Abstract: A field emission display panel of the diode structure that has a dual-layer cathode and an anode formed on a bottom glass panel and a method for such fabrication are described. In the FED panel, a plurality of emitter stacks is formed each having a layer of dielectric material, a first layer of a conductive paste coated with a layer of nanotube emitters on a peripheral, sidewall surface as a cathode, and a second layer of the conductive paste deposited on top of the nanotube emitter layer. The first layer and the second layer are formed in a column shape. The second conductive paste layer stops any nanotubes left on a top surface of the first conductive paste layer from emitting electrons in an upward direction and restricts all emitted electrons in a downward direction.

Abstract: There is disclosed an image forming apparatus in which electric discharge by a peeled metal back film is prevented. In the image forming apparatus provided with a rear plate having an electron emitting device, and a face plate having a conductive film and a fluorescent layer having fluorescent particles, the conductive film is disposed on the fluorescent layer. When an average thickness of the fluorescent layer is set to d, an average particle diameter of the fluorescent particles is rp, and the thickness of the fluorescent film is D, D−rp≦d≦D+rp is satisfied.

Abstract: The present invention provides co-doped zinc oxide to flat panel, light emissive display devices and vacuum microelectronic devices to improve their efficiency and lifetime. This material has a low growth temperature and is compatible with metal oxide semiconductor (MOS) processing technology. It is tranparent, chemically stable and has a low work function, which result in many advantages when being used as the cathode for the aforementioned devices. In one embodiment of the emissive display device, an organic light diode (OLED) display has a high work function metal anode, such as platinum (Pt), gold (Au) or nickel (Ni) and a low work function co-doped zinc oxide cathode. Because of the energy level alignment provided by these two materials, the potential energy barriers to injection of electrons from the cathode and holes from the anode into the organic emissive medium are minimized so the display device operates more efficiently.

Abstract: An organic electroluminescent display is provided, which can sufficiently control a change of a shade by luminescence of an electron transport layer or a hole transport layer itself, and can always hold a stable chromaticity, and a production method of the same, and an organic electroluminescent display. On a glass substrate is formed a transparent electrode composed of ITO (Indium-Tin-Oxide) as an anode. In addition, on the anode is formed an organic EL layer composed of a hole transport layer which transports a hole, a luminescent layer which emits light by a combination between a hole and an electron, and an electron transport layer which transports an electron. Further, on the electron transport layer is formed a cathode.

Abstract: An organic EL display device is provided which has excellent uniformity of luminosity within the display area, even if the display area is relatively large. A plurality of cathode terminals connected to a cathode layer that is disposed on the display area are provided at different locations on the substrate.

Abstract: An EL lamp for emitting light in multiple color which includes a first light-permeable electrode layer formed at the back side of a transparent substrate, a first luminous material layer containing a first luminous material, an intermediate light-permeable electrode layer, a second luminous material layer containing a second luminous material, a back electrode, and at least two elements of (i) a first color material contained in the first luminous material layer, (ii) a second color material contained in the second luminous material layer, and (iii) luminous color converting layer containing a third color material, disposed between the first luminous material layer and second luminous material layer, and a color coat layer containing a fourth color material, disposed at the front surface side of the transparent substrate. The color material closer to the back electrode of the at least two elements has the color of longer wavelength than the remoter color material.

Abstract: An apparatus for removing contaminants from a display device is disclosed. In one embodiment, an auxiliary chamber is adapted to be coupled to a surface of a display device such that contaminants within the display device can travel from the display device into the auxiliary chamber. A getter is disposed in the auxiliary chamber. The getter is adapted to capture the contaminants once the contaminants travel from the display device into the auxiliary chamber. In other embodiments, the getter is disposed in the border region surrounding the active area of the display.

Abstract: In a flat display device, display can be carried out with high definition and high density, and furthermore, driving power, that is, consumed power can be reduced. First and second substrates 1 and 2 are provided opposite to each other, the first substrate 1 is provided with a discharge maintaining electrode group 5 having a plurality of discharge maintaining electrodes 3 and 4 arranged thereon, and the second substrate 2 is provided with an address electrode group 9 having a plurality of address electrodes 8 arranged thereon. The discharge display is carried out through negative glow discharge and cathode glow discharge.

Abstract: A PDP minimizes a capacitance of phosphors by removing some of the phosphors of each discharge cell to maintain almost same discharge voltage level applied to discharge areas of each discharge cell. The PDP includes a plurality of lower electrodes successively formed on a first substrate in row direction, a plurality of isolation walls formed between the lower electrodes, a plurality of upper electrode sets successively formed on a second substrate opposite to the first substrate to cross the lower electrodes, and a phosphor formed on the first substrate to expose some of the lower electrodes crossed the upper electrode sets.

Abstract: Start-up and re-ignition of a high pressure arc lamp are aided by injection of electrons toward a high pressure arc lamp electrode. A microdischarge device directs electrons toward an electrode of the arc lamp and is preferably turned off during normal operation of the arc lamp. The harsh environment of an arc lamp requires the microdischarge to be made from robust materials, such as ceramics, semiconductors or tungsten, for example. In the present invention, the discharge design must allow, preferably through a screen anode, for the escape of electrons from the microdischarge. This invention results in a decrease in the voltage required to start-up or re-ignite a lamp.

Abstract: A satellite power distribution method for efficiently distributing power to satellite electric propulsion thrusters (24) is provided. The satellite includes spacecraft loads (20), an electric propulsion thruster (24), thruster auxiliary circuits (22), and a first power transformer (30). The first power transformer (30) has a primary winding (32) coupled to a first energy source (12) that supplies satellite power. A first secondary winding (36) of the first power transformer (30) is coupled to the spacecraft loads (20) for supplying primary power. The power distribution method includes the steps of first coupling a second secondary winding (34) to the first power transformer (30) for converting the satellite power to thruster discharge power which is rectified. The rectified discharge power is filtered to obtain power that is supplied to the electric propulsion thruster (24). Finally, satellite power is converted to auxiliary power for powering the thruster auxiliary circuits (22).

Abstract: A section of pipe, for a device for treating a gas by exciting the latter by way of incident microwave radiation suitable for producing a surface-wave plasma in the gas, including a discharge tube made of dielectric material intended to pass through the device in a region for concentrating the incident radiation. The tube comprises, over at least part of its length, a double wall.

Abstract: An active-matrix light-emitting apparatus is provided having step-cutting insulation films, each film having upper portions protruding as overhang sections in interlayer portions of pixel electrodes and light-emitting layers in border regions of interpixel sections. Therefore, the light-emitting layers, even when formed so as to overlap a plurality of pixels and to produce step cutting at the overhang sections, are insulated in each of the pixels. Accordingly, crosstalk is avoided in these interpixel sections, and display quality is improved.

Abstract: A number of light-emitting fibers in side-by-side array comprise a display. Each fiber includes a number of light-emitting elements disposed along the length of one surface of an optical fiber, such as an electro-luminescent material, e.g., an OLED material, disposed between hole injecting and electron injecting electrodes. Contacts on the top ones of the electrodes are connected by a conductor disposed transverse to the longitudinal direction of the fiber. The conductors are preferably deposited on the optical fibers by mask deposition, preferably utilizing masks adapted for contemporaneously depositing a metal conductor across a plurality of fibers. Electronic circuits having patterned conductors corresponding to the transverse conductors may be connected thereto by solder, conductive adhesive and the like.

Abstract: A DC/DC converter for an electronic equipment, e.g., a self-luminous display apparatus, includes a plurality of choke coils connected in parallel to each other to a DC power supply, a control circuit for controlling the ON/OFF operation of a switching element to control an output voltage of the DC/DC converter, and a changeover switch for selectively changing over the choke coils such that only one of the choke coils which has an inductance value corresponding to the output current of the DC/DC converter is effectively connected to the rectifying diode.

Abstract: A controller for controlling the intensity of an electroluminescent display is disclosed. The controller controls a number of skipped cycles in a cycle set of an applied waveform to the electroluminescent display to vary the average duty cycle, and thereby adjust the intensity of the electroluminescent display. The controller is further configured to adjust the intensity of individual channels within the electroluminescent display to provide compensation for display aging, color variation, as well as for varying intensity for various operating modes.

Abstract: An alternating current driven type plasma display device having (a) a first panel comprising a first substrate; a first electrode group constituted of a plurality of first electrodes formed on the first substrate and a protective layer formed on the first electrode group and on the first substrate and (b) a second panel comprising a second substrate fluorescence layers formed on or above the second substrate; and separation walls which extend in the direction making a predetermined angle with the extending direction of the first electrodes and each of which is formed between one fluorescence layer and another neighboring fluorescence layer, wherein discharge is caused between each pair of the first electrodes facing each other, and a recess is formed in the first substrate between each pair of the facing first electrodes.

Abstract: A lighting system (1) having a high intensity discharge lamp (16) and an electronic ballast having a variable frequency generator (10) which is arranged to vary the frequency of the ballast output over a range of frequencies having a minimum frequency of 400 kHz; a reactance is included in a joint operating circuit (22) in and between the ballast generator (10) and lamp (16) such that the circuit resonate to provide a starting voltage for the lamp at or above the minimum frequency. The arrangement inhibits lamp flickering and improves overall lamp and system efficiency.

Abstract: Methods and systems for providing emission of incoherent radiation and uses therefor are disclosed. A system for providing emission of high peak power (in watts) incoherent radiation, comprises an electrically impeded discharge lamp linked to an electrical energy supply.

Abstract: A resonant converter which may be employed as an electronic ballast for a gas discharge lamp, the converter being in the form of a full or half bridge circuit which includes at least a pair of power switches such as MOSFET's. The gates of the switches are actuated by substantially square wave cyclic gating signals having complementary duty cycle ratios and a frequency somewhat above a resonant frequency of the converter circuit. The energy supply to the lamp is variable in accordance with the duty cycle ratios of the gating signals. In order to avoid generation of high voltage and current transients in the converter when a change in operating state requiring a substantial change in duty cycle ratios of the gating signals is to be performed, as when effecting turn-on or turn-off of the lamp, the changes in the duty cycle ratio are ramped to occur incrementally over several cycles of the gating signals rather than directly to required final values of the duty cycle ratios.

Abstract: An energy saving electronic control circuit for fluorescent tubes, where it controls the tubes' light output. This system uses a half-bridge topology, which is supplied from an AC to DC current source obtained from the mains supply. The switching transistors are driven at rather high frequencies. An inductor is connected in series with a capacitor, forming an LC circuit, which is connected to the junction between the switching transistors and these resonant at the same switching frequency of the transistors. At least one tube is connected across one capacitor, in other words in series with the inductor at one end and at the center junction of a passive half-bridge formed by two capacitors in series.

Abstract: The format of a color video signal that has been inputted into a CPU from a video amplifying circuit is identified, and based on a given parameter variable according to this identified format, a second grid electrode voltage and the cathode bias voltages of cathodes for the three primary colors are determined, thereby driving a cathode ray tube with an optimal driving condition adequate for the video signal format. This parameter variable may be adjusted through a manual operation, allowing a user to set any desired driving condition for the cathode ray tube.

Abstract: A method and system are disclosed for spinning the spindle motor of a disk drive from a stationary state to an operable state that is suitable for performing a memory access operation. The method and system include energizing the polyphase motor in a first predetermined commutation phase; detecting whether a zero crossing of a back electromotive force (bemf) signal corresponding to the first predetermined commutation phase occurs; sensing whether the polyphase motor advanced to a next successive commutation phase relative to the first predetermined commutation phase; and performing an acceleration procedure to accelerate the speed of the polyphase motor towards a desired speed based upon a detected zero crossing of the bemf signal and an affirmative determination that the polyphase motor advanced to a next successive commutation phase relative to the first predetermined commutation phase.

Abstract: A power window control apparatus for controlling vehicle power windows (12-18) includes window control switches (52-58) for controlling power window control motors (20-26). When two window control switches (52-58) are simultaneously and momentarily actuated downward, a controller (40) controls the motors (20-26) to lower the windows (12-18) to a predetermined position from an initially closed position. In the event that one or more windows are initially open, the controller (40) lowers the windows for the time interval that the two window control switches are actuated downward. When the two window control switches (52-58) are moved in the upward direction, the controller (40) simultaneously controls all the motors (20-26) to raise all open windows (12-18) to a fully closed position.

Abstract: The invention relates to a method for regulating an electric-motor-driven adjusting device, in particular for vehicles, having a safety circuit (5) for reversing or stopping a drive motor, and to an apparatus for performing this method. To enable fast, safe detection in the event of something becoming caught or pinched, it is provided that an actual value is regulated via a closed-loop control circuit to a set-point value, the actual value or set-point value is a signal having a frequency proportional to the rpm or load on the drive motor, and the phase difference detected with a comparison member of the control circuit is utilized to activate the safety circuit.

Abstract: A system for positioning a read/write head having a voice coil suitable for coarse control and a piezoelectric transducer (PZT) suitable for fine control. A voice coil control signal and a PZT control signal are generated from a position-indicative signal, both receiving power via a shared supply having a nominal rectified voltage V1. In a preferred method, control signals are both applied to the voice coil and PZT when amplified so that each has a saturation voltage smaller than |V1|.

Abstract: In a robot area monitoring device, in which at least one area of a rotary movement about at least one robot axis is monitored, initiators cooperating with part annular cams arranged coaxially to the axis to be monitored are provided, the initiators being connected to an evaluating device.

Abstract: Method and apparatus for eliminating greater than twice motor overvoltage by altering modulating signals provided to a PWM controller which in turn provides firing pulses to a PWM inverter. The modulating waves are altered by either tying them to positive or negative DC buses or limiting the maximum magnitudes to a maximum magnitude value above which modulating waveforms are known to cause greater than twice overvoltage. Pass through modulating waveform angles at which waveforms have to be modified are determined as a function of modulating waveform symmetries and the first pass through angle within a waveform cycle.

Abstract: In a method for controlling an electric drive, a controlled variable is adjusted to a desired value. To protect the electric drive, the controlled variable is first adjusted to the desired value in a precise manner. Thereafter, the control operation is interrupted, AND the difference between the controlled variable and the desired value is check continuously to see whether it exceed a preset threshold. Interruption of the control operation is terminated when the threshold has been reached or exceeded.

Abstract: A method for controlling a stepping motor that moves an object from an initial position by a target distance. The method includes calculating a moved distance of the object, calculating a remaining moving distance of the object, updating a first velocity value until the moved distance exceeds a first reference value, updating a first position value indicating the present position of the accelerated object by adding the updated first velocity value to the first position value, updating a second velocity value when the remaining distance is less than the second reference value by subtracting a second acceleration value from the second velocity value, and updating a second position value indicating the present position of the decelerated object by adding the updated second velocity value to the second position value.

Abstract: A start-up procedure for a multiphase brushless motor to be accelerated until reaching a certain speed includes determining the starting position of the rotor and performing an excitation phase including forcing a drive current in the phase windings of the motor for an established period of time. This is done according to a switching sequence for inducing a rotation in the desired direction. Furthermore, the method may include sensing the position reached by the rotor at the end of each excitation phase. The start-up procedure is eventually interrupted when the established speed has been reached or exceeded. Additionally, the duration of a next phase of excitation may be increased or reduced, and the switching sequence may be modified, based upon the number of consecutive times in which the current position is found to be the same or different from the previously detected position, respectively.

Abstract: When the amount L of actual load change that is picked up from an external plant control device exceeds a reference level L* of load change amount per prescribed unit time that is pre-set to serve as an impact drop detection level, the d axis field current Id is suppressed to a prescribed limiting amount. The d axis voltage reference Vd* and hence the motor and armature voltage Eac are thereby suppressed exclusively during a prescribed field limiting period Td. A large potential difference (voltage margin) is thereby generated between the converter output voltage Vac and AC motor armature voltage Eac, thereby speeding up the rise of output current of the motor. Subsequent recovery of the motor speed after impact drop is speeded up by returning the voltage level to the original d axis voltage reference Vd*.

Abstract: In a small electric motor vehicle equipped with an electric motor for driving wheels through a reduction gear mechanism, a first predetermined voltage is immediately applied to the electric motor when a drive-off instruction is generated from vehicle standstill and then the voltage is increased at a predetermined rate until the voltage exceeds a second predetermined voltage, and is then controlled such that the driving speed converges to a desired speed. With this, since the application of the first predetermined voltage slightly rotates the electric motor to take up reduction gear mechanism backlash, shock at drive-off caused by reduction gear mechanism backlash can be reduced or eliminated even when a high-capacity electric motor is used to enhance hill-climbing performance, and smooth drive-off is possible.

Abstract: A motor controller drives a motor based on signals from commutation sensors (CS signals.) This controller includes (a) a pole position detector for detecting a rotor pole position with edges of the CS signals; (b) a speed detector for detecting a motor speed based on a time interval between the edges of the CS signals; (c) a pole phase detector for estimating a position angle of the rotor based on an output from the position detector and an output from the speed detector; and (d) a phase limiter for restraining the estimated position angle from advancing over a given value. When the limiter continues operating for a certain interval, the controller switches the motor from sine wave driving to rectangular wave driving. This structure allows this controller to drive the motor stably when the motor speed is abruptly changed in the sine wave driving or under field weakening control.

Abstract: Batteries are often used for load-following, particularly in combination with generation sources that cannot respond to fast load changes. Batteries that display “memory” (i.e., their ability to operate correctly over their entire depth of discharge depends on their previous level of charge or discharge) cannot adequately follow loads. This invention allows the use of batteries that display “memory” in load-following applications.

Abstract: A controller controls a switch bank which can shunt a voltage source in parallel with one or more fuel cells in a stack. By controlling the voltage of the voltage source, the current through the fuel cells is directly controlled. By increasing the anode potential of the fuel cell through control of the voltage source, poisons deposited on the electrocatalyst are removed, thereby rejuvenating the fuel cells. Fuel cells in a stack can be treated in turn, causing a reduction of the effects of electrocatalyst poison on stack performance.

Abstract: An capacitor tub assembly which includes arrays of capacitor cells coupled in series and grouped into sub-packs. The capacitors within each sub-pack being electrically coupled via a unique printed circuit board (PCB) design, wherein individual PCBs cover the top and bottom ends of each sub-pack. Each sub-pack is further electrically coupled to each of the other adjacent sub-packs within the tub assembly, thereby ensuring that all the capacitor cells in the capacitor tub assembly are electrically coupled.

Abstract: The regulator includes a control circuit for controlling a transistor switch. The switch has an output coupled to a field terminal which is to be coupled to the rotor's field coil. The regulator also includes a stator terminal coupled to the control circuit; an ignition terminal coupled to the control circuit for turning the regulator on and off; and a positive battery terminal coupled to the control circuit. A bank of capacitors is coupled between the stator terminal and the input of the switch. The rectifier has an anode coupled to the battery terminal and a cathode coupled to the input of the switch. The capacitor bank in conjunction with the rectifier boost the voltage to the switch and the field. This increases the maximum output of the alternator.

Abstract: A low power mode and feedback arrangement for a switching power converter. Two or more main power switches, such as transistors, transfer energy from a supply to load by their opening and closing. When the load requires a relatively low power level, this condition is detected. In response, one or more of the transistor switches is disabled from switching and the reduced power requirements of the load are handled by the remaining one or more transistor switches. As a result, switching losses are reduced. This is because parasitic gate capacitance and on-resistance associated with the disabled switches no longer consume power from the power source. The invention provides significant efficiency advantages during periods when the load draws a low level of power. This is especially useful for battery-powered devices which may operate in a low power mode for extended periods of time, such as standby mode as in a portable telephone.

Abstract: An apparatus and method for a regulator circuit includes multiple amplifier circuits, multiple bias stages, and a shunt stage. Each bias stage includes a set of MOS transistors with respective resistance circuits that are arranged to bias the shunt stage. The shunt stage includes a set of MOS transistor that are arranged to regulate a potential provided by a source circuit when active. Each amplifier circuit forms a regulation loop with a respective MOS transistor of the bias stage and a MOS transistor of the shunt stage. The multiple regulation loops provide redundancy. The regulation loops do not conflict with each other. Failures or defects within one of the regulation loops does not affect the remaining regulation loops in such a way that over-voltage results from the failure. The regulator prevents an over-voltage when at least one of the regulation loops is operable.

Abstract: The low dropout voltage regulator (LDO) circuit with improved power supply rejection ratio includes: a first amplifier 20 having a first input coupled to a reference voltage node Vref; a second amplifier 22 having an input coupled to an output of the first amplifier 20; a pass transistor 24 having a control node coupled to an output of the second amplifier 22; a feedback circuit 26 and 28 having an input coupled to the pass transistor 24 and an output coupled to a second input of the first amplifier 20; an inverting gain stage 36 coupled to the input of the second amplifier 22; and a high pass filter 42, 44, and 38 coupled between a power supply node and a control node of the inverting gain stage 36. The circuit uses the high pass filter 42, 44, and 38 and inverting gain stage 36 to feedforward the power supply ripple into the LDO's control loop which counter-acts the impact of the supply ripple on the output node Vo.

Abstract: A step-down constant-current transformer including a controllable switch downstream from the one input and connected in series to a choke, a capacitor connected in parallel at the output, and upstream from the choke, a second controllable switch in parallel. Both controlled switches are MOSFET transistors. A control unit, in particular a pulse-width control unit, is provided for the MOSFET transistors. The voltage across the parallel-connected MOSFET transistor is monitored to determine whether a reverse current, i.e., a current flowing through the choke from the output in the direction of the input of the constant-current transformer, or an electric potential at the center tap of the half-bridge formed by the two MOSFET transistors is detected. For this purpose, a comparator and an AND circuit are provided, which, in the event of such a reverse current, block the parallel-connected MOSFET transistor to prevent the reverse current.