148 results about "Fast pulse" patented technology

A capacitor is connected to the output of a multiphase power converter, and a current-driven device (e.g., LED or laser diode) is also connected to the power converter output. A solid state switch (FET or IGBT) is connected in series with the current-driven device. Means are provided for sensing current through the current-driven device. An error amplifier compares sensed current through the current-driven device with a current level demand signal and controls the output of the power converter. Means are provided for turning the switch on and off and may be (i) a fast comparator receiving a voltage reference signal at one input and the current level demand signal at another input, and outputting the switch on / off signal to the switch or (ii) an externally-generated logic signal provided directly to the switch.

A fiber laser system includes a predominately single spatial mode, linearly polarized master oscillator providing a set of optical pulses and a polarization-maintaining optical isolator optically coupled to the master oscillator. The fiber laser system also includes a fiber amplifier optically coupled to the optical isolator and including a power amplifier comprising a double clad gain fiber, one or more pump lasers, and a pump coupler. The fiber laser system further includes a pulse compression stage optically coupled to the fiber amplifier. The pulse compression stage includes a volume holographic phase grating. Moreover, the fiber laser system includes a nonlinear frequency conversion stage optically coupled to the pulse compression stage.

A system for delivering pulses of a desired mass of gas to a tool, comprising: a mass flow controller including flow sensor, a control valve and a dedicated controller configured and arranged to receive a recipe of a sequence of steps for opening and closing the control valve so as to deliver as sequence of gas pulses as a function of the recipe. The mass flow controller is configured and arranged so as to operate in either one of at least two modes: as a traditional mass flow controller (MFC) mode or in a pulse gas delivery (PGD) mode. Further, the dedicated controller is configured and arranged to delivery pulses of gas in accordance with anyone of three different types of pulse gas delivery processes: a time based pulse delivery process, a mole based pulse delivery process and a profile based pulse delivery process.

Pulsed laser drivers are disclosed comprising Gallium Nitride (GaN) power transistors for driving diode laser systems requiring high current and fast pulses, such as laser drivers for LIDAR (Light Detection and Ranging) systems. Drivers are capable of delivering pulses with peak current ≥100 A, e.g. 170 A to provide high peak power, fast pulses with nanosecond rise times and nanosecond pulse duration, for driving multi-channel laser diode arrays with 40 A per channel for 120 W output per channel for a combined peak output of 480 W. For lower duty cycle, example driver circuits are disclosed comprising a high current power transistor for direct drive with drive assist. For higher duty cycle, example resonant driver circuits are disclosed comprising two high current power transistors. Implementation of resonant driver circuits with GaN technology provides fast charging for short pulse operation at higher repetition rates or for pulse code modulation.

The invention relates to a high-precision and fast pulse metering device and a high-precision and fast pulse metering method. The method solves the problems of low precision and long time in the conventional pulse metering method. The pulse metering device comprises a standard meter and a measured meter, wherein the standard meter is connected with a first pulse timing and counting unit, and the measured meter is connected with a second pulse timing and counting unit; and input ends of the first pulse timing and counting unit and the second pulse timing and counting unit are connected to a signal control unit, and output ends of the first pulse timing and counting unit and the second pulse timing and counting unit are connected to a micro processing unit. The pulse of the standard meter is compared with the pulse of the measured meter, the number of the pulses and the correct time of the standard meter and the measured meter are measured in an interval respectively, the number of the pulses of the measured meter is corrected, and a measured flow meter which outputs a pulse signal is metered quickly and accurately, so that the working efficiency is improved and the energy is also saved.

Vapor concentrators are used to provide a higher concentration of trace target vapor than would normally be available in the environment. This is accomplished by allowing the trace target vapor to adsorb onto a concentrating surface and subsequently releasing the trace target vapor by heating the surface. An improved desorbing method is providing by a fast pulse of photons, which only heats the near surface region, rather than the entire mass of the substrate on which the concentrating surface resides. Since all of the trace target vapor is released in a short time interval, the vapor is less diluted by carrier gas than would occur during the slower temperature ramp that results when the entire substrate mass is heated. A more highly concentrated target vapor is produced with less input of energy.

Embodiments of the present invention provide an inexpensive and fast pulse characterization platform capable of real time operation, suitable for acquisition of single-photon data. Embodiments of the present invention include both a digital multi-channel data acquisition instrument and an analog pulse acquisition instrument suitable for a wide range of applications in physics laboratories. An FPGA performs multi-channel acquisition in real time, time stamps single events, and determines if the events fit a predetermined signature, which causes the events to be categorized as a coincidence. The indications of coincidences are then communicated to a host computer for further processing as desired.

A fast pulsed nonthermal plasma reactor includes a discharge cell and a charging assembly electrically connected thereto. The charging assembly provides plural high voltage pulses to the discharge cell. Each pulse has a rise time between one and ten nanoseconds and a duration of three to twenty nanoseconds. The pulses create nonthermal plasma discharge within the discharge cell. Accordingly, the nonthermal plasma discharge can be used to remove pollutants from gases or break the gases into smaller molecules so that they can be more efficiently combusted.

Image formation via photoinduced fluorescence changes in a polymeric medium with two-photon fluorescence readout of a multi-layer structure. Fluorophore-containing polymers, possessing one or more basic functional groups, underwent protonation in the presence of a photoinduced acid generator upon exposure to a broad-band UV light source or fast-pulsed red to near-IR laser irradiation. Solution studies demonstrated formation of monoprotonated and diprotonated species upon irradiation, each resulting in distinctly different absorption and fluorescence properties. The fluorescence of the original, neutral, fluorophore was reduced upon monoprotonation, leading to a concomitant increase in fluorescence at longer wavelengths due to the monoprotonated form, the basis for multichannel data readout. Experiments in polymer films demonstrate the changes in fluorescence properties of the photosensitive polymer compositions and polymers can be employed for a high storage density, write-once read-many (WORM) data storage medium with two-photon fluorescence readout. Two-channel, two-photon fluorescence imaging provided both “positive” and “negative” image readout capability.

The invention discloses a pulse modulation drive circuit of a miniature semiconductor laser. The pulse modulation drive circuit comprises an external power supply interface circuit, a pulse generating circuit, a pulse shaping circuit, a high-speed pulse amplifier circuit, and a laser driver main power generation circuit. When the provided pulse modulation drive circuit is applied to the semiconductor laser, the power consumption and heating value of the semiconductor laser can be reduced; and the circuit has a small size and is suitable for a hand-held semiconductor laser with the small physical space. Meanwhile, the circuit has characteristics of simple structure, reliable performance, fast pulse response, high pulse output power, and high anti-interference performance.

A coil used for fast pulse superconducting magnet winding structure has an epoxy gasket (5) arranged on a frame (4) with a hole; a first layer of superconducting winding (6) is winded on the epoxy gasket (5); a layer of epoxy glass ribbon (7) is winded between the first layer of the superconducting winding (6) and a second layer of superconducting winding (8) which are bonded together by low-temperature epoxy resin; and epoxy glass steel strips (9) are distributed on the surface of the second layer of the superconducting winding (8) at equal intervals along the circumference direction of the winding. The superconducting wire used by the superconducting winding of the coil is formed by coating a composite matrix (2) consisting of CuNi and copper outside a superconductor (1), wherein an insulating layer (3) is coated on the composite matrix (2). The coil has higher mechanical stability and better heat transfer characteristics, and is suitable for a fast-excitation large-scale superconducting coil with high energy-storing density and high magnetic field.

The invention provides a broadband saturable absorber comprising a gold nanorod and a surface decoration material which coats the surface of the gold nanorod. A core-shell structure composite nano material is formed by the gold nanorod and the surface decoration material. According to the broadband saturable absorber, the damage threshold of a saturable absorber is greatly improved, and the stable operation of an ultrafast pulse can be realized.

A repetitive frequency fast pulse hard X-ray generator, diode of the invention is constructed by fixed supporting tubular and sliding supporting tubular, they are connected tightly by the bellows, and grooved rail is set on the bell socket part, rotating otter cylinder is set at the outer to drive the sliding supporting tubular move along the grooved rail; cathode connecting bar is set at the axis in cavity, the front end is cathode target; conical packing ring is set in the cavity of diode to divide the cavity into fore vacuum chamber and back oil recess; anode assembly are fixed at the fore and outer end of the diode. The invention designs the diode to be an active structure, that resolves the technique puzzle of stability of power source, vacuum tightness of diode, axiality of dynamic and static supporting, flexible adjustment on-line; on the precondition of not destroying the vacuum, adjusting aspect ratio flexibly can be realized, the current detecting detector is built; it possesses advantages of flexible structure, repeatable frequency or running for one time, and the pulse width, intensity and power spectrum can be adjustable continuously, it compensates for defects of current technique, and it provides ideal field of radiation for development and application of new type rapid response detector, building fast pulse hard X-ray metering standard, physical mechanism research of diode and pulse ray dynamic imaging technique.

A high voltage, fast pulse rise / fall time, and high repetition rate pulse generator solves the high pulse repetition rate limitations associated with RF power amplifiers and gap switch type pulse generators. The pulse generator employs a transmission line architecture and structural techniques that allow for continued high voltage, fast rise / fall time, and high repetition pulse rate operation of the pulse generator without impairment of the pulse generator while exceeding performance characteristics achievable with conventional RF power amplifiers and gap switch type pulse generators.

The invention provides a photoelectric position detector with high sensitivity. The detector comprises a Si substrate and two electrodes. TiN film is epitaxially grown on the Si substrate by a film making method; the electrodes are respectively prepared on both sides of the Si substrate by a film coating method or a welding method. When a light spot illuminates the surface of the detector, a voltmeter is used for measuring a voltage between the electrodes; or a voltage source is connected between the electrodes and the TiN to cause a schottky diode composed of the TiN and the Si to work under a reverse bias condition, and then the current between the electrodes is measured; therefore, the position of the light spot can be determined according to the measured voltage or the current. The photoelectric position detector has the advantages of simple structure, good linearity and high sensitivity, can directly detect the voltage or the current without an additional amplifying circuit, and can detect millimicrosecond level fast-pulse signals.

A system and method are configured to deliver pulses of desired mass of gases. The system delivers a plurality of sequences of pulses of a desired mass of gas through at least two flow channels. The system comprises: a multi-channel fast pulse gas delivery system including (a) a plurality of flow channels, each channel comprising a flow sensor and a control valve, and (b) a dedicated controller configured and arranged to receive a recipe of one or more sequences of steps for opening and closing at least some of the control valves so as to deliver as a sequence of pulses of at least one gas through each of the corresponding channels as a function of the recipe. The method comprises: receiving at a dedicated controller from a host computer the prescribed recipe of one or more sequences of steps of pulses of one or more gases to be delivered through the plurality of flow channels; and using the sequence of steps to control each flow channel including a flow sensor and a control valve by opening and closing the control valve of each flow channel in accordance with the sequence of steps of the recipe.

The invention relates to a compact type fast pulse discharging unit, which comprises a first pulse capacitor, a second pulse capacitor, a three-electrode gas switch, guiding connectors and an insulated support frame, wherein the first pulse capacitor and the second pulse capacitor are fixedly arranged on the insulated support frame; the three-electrode gas switch is fixedly arranged between the first pulse capacitor and the second pulse capacitor; and the first pulse capacitor, the second pulse capacitor and the three-electrode gas switch are fixedly connected to each other through cylindrical electrodes of the pulse capacitors and upper and lower guiding connectors of the three-electrode gas switch. The compact type fast pulse discharging unit has the advantages of high output voltage, compact structure, small loop inductance and the like, and can meet the demand on outputting a fast rise time high-power pulse.

The invention relates to a high-voltage repetition-frequency pulse generator which comprises a high-voltage power supply, a charging resistor, an energy storage capacitor, an output cable, a switch, a ground resistor, a ground connecting plate and an insulating support; and the high-voltage repetition-frequency pulse generator is characterized in that a hydrogen thyratron is adopted as the switch; backflow tubes are arranged on the exposed parts of the hydrogen thyratron, the energy storage capacitor and the output cable; the high-voltage end of the energy storage capacitor is directly connected with the switch of the hydrogen thyratron; the low-voltage end of the energy storage capacitor penetrates the insulating support by utilizing a screw and then is connected with the ground resistorthrough the ground connecting plate; and the other end of the ground resistor is connected with the ground potential. The high-voltage repetition-frequency pulse generator is mainly characterized by fast rise time (25ns), high amplitude (50kv), low jitter (3ns), capability of running stably at a repeated frequency, high front edge steep and amplitude of the output pulse, capability of being used for pre-stage triggering of a pulse power source, and capability of being used as a fast pulse source experimental platform for research on insulating characteristic of materials.

An orally taken salbutamol able to release active components in the sequence: predefined time lag, fast pulse release, and slow release is composed of a slow-release microsphere containing salbutamol, a coated quick release layer, and a coated time-lagging layer.

A system and method are configured to deliver pulses of desired mass of gases. The system delivers a plurality of sequences of pulses of a desired mass of gas through at least two flow channels. The system comprises: a multi-channel fast pulse gas delivery system including (a) a plurality of flow channels, each channel comprising a flow sensor and a control valve, and (b) a dedicated controller configured and arranged to receive a recipe of one or more sequences of steps for opening and closing at least some of the control valves so as to deliver as a sequence of pulses of at least one gas through each of the corresponding channels as a function of the recipe. The method comprises: receiving at a dedicated controller from a host computer the prescribed recipe of one or more sequences of steps of pulses of one or more gases to be delivered through the plurality of flow channels; and using the sequence of steps to control each flow channel including a flow sensor and a control valve by opening and closing the control valve of each flow channel in accordance with the sequence of steps of the recipe.

A device for real-time shutdown protection of high-voltage fast pulse signals, the pulse signal generator (1) generates a control signal for high-voltage fast pulse generation, controls the pulse power supply (2) to generate high-voltage fast pulses, and acts on the experimental chamber (3) , the discharge current of the experimental cavity (3) is introduced into the current measurement sensor (4), and the voltage signal on the current measurement sensor (4) is connected to a measurement channel of the digital oscilloscope (5), as the trigger source of the oscilloscope, a suitable trigger level. Once the medium breaks down, the discharge current is too large, and the voltage signal on the current measurement sensor (4) is enough to trigger the oscilloscope (5), then the trigger feedback port of the oscilloscope (5) will immediately output a TTL logic signal, which passes through the signal The conversion circuit (6) performs processing, outputs a signal conforming to the shutdown signal interface standard of the pulse signal generator, and turns it off, thereby playing a protective role. The time delay of the present invention can be controlled within 10 μs.

The invention relates to a vacuum diode with high current, small focal spot and long service life. The original diode in a repetition frequency fast-pulse hard X-ray generator is modified, the structure and the material of movable cathode and anode assemblies are improved, a cathode head is made of tungsten nickel copper alloy materials and is seated on a movable support, a conical hole structure inwards forming a sharp end bulge is used for emitting electrons and is aligned with X rays, and an anode target is made of metal tantalum materials and is fixedly arranged on a copper core wire through screw threads. The conical annular cathode structure is improved, the radius of sent plasmas is favorably controlled, dense plasmas can be conveniently obtained, the self pinching condition in the electronic beam transporting process is met, submillimeter beam spots are formed, and the detailed imaging requirement of the pulse imaging field is met.

A high voltage, fast pulse rise / fall time, and high repetition rate pulse generator solves the high pulse repetition rate limitations associated with RF power amplifiers and gap switch type pulse generators. The pulse generator employs a transmission line architecture and structural techniques that allow for continued high voltage, fast rise / fall time, and high repetition pulse rate operation of the pulse generator without impairment of the pulse generator while exceeding performance characteristics achievable with conventional RF power amplifiers and gap switch type pulse generators.

The invention discloses high voltage fast pulse power supply based on a DSRD. The high voltage fast pulse power supply based on the DSRD is characterized in that a pump circuit of the DSRD is an inductive adder pump circuit which comprises M pulse power modules. Each pulse power module comprise a switch S1, a switch S2, an energy-storage capacitor C0, a resonant capacitor C1, a n:n turn resonancetransformer T1 and a 1:1 turn transformer T2. One end of each S1 is grounded and primary of each T1 is connected to the other end of each S1 through each C0, the other end of the primary of each T1 isgrounded, the other end of each secondary of each T1 is connected with primary of each transformer T2 separately through each resonant capacitor C1 and is grounded through each switch S2, and the other end of the secondary of each resonance transformer T1 is connected with the other end of the primary of each transformer T2 and is grounded separately. The secondary of each transformer T2 of eachpulse power module is stacked and connected in series together to provide a bidirectional pumping pulse for a DSRD stack. The high voltage fast pulse power supply based on the DSRD solves the problemof pulse power stacking of a high repetition frequency DSRD fast pumping circuit.

The present invention discloses a square wave signal generator. The square wave signal generator includes a direct digital synthesizer (DDS) module, a wave shape selecting unit and a comparator. The DDS module is connected with the wave shape selecting unit. The wave shape selecting unit is connected with the comparator. At low frequency and high frequency, the square wave signal generator separately selects different initial signals as initial wave shapes. At low frequency, a fast pulse signal is selected, and at high frequency, a basic wave shape signal is selected. Level comparison and shaping are performed by using a comparator circuit, so that a low frequency square wave that is faster, jitters lower, and has a fine and adjustable duty cycle is obtained, and a high frequency square wave that is faster and jitters lower is obtained. The square wave signal generator has the advantages of the fast pulse signal and the comparator circuit.

The invention relates to a charging and repairing management method and a charging and repairing device for a lead acid battery of an electric vehicle. The charging and repairing management method comprises a fast pulse charging stage, a variable pulse charging stage, a trickle charging stage and a pulse maintenance stage. The charging and repairing device realizes the charging and repairing management method by using the control of a single chip microcomputer. The invention discloses a pulse type charging repair control method, which adopts constant voltage and current limiting switching power supply technology, under the control of a single chip microcomputer, a charging repair device turns on and off the output current at a high speed, changes the direct current into a high-frequency charging pulse, and uses a digital control mode to precisely control the duty cycle of the charging current pulse.

The invention relates to a test method and device of the magnetization characteristic of a magnetic core under a fast pulse voltage. By adopting the primary pulse voltage gradient, i.e., Vp / (n.Se.tr) of a unit area single-turn feed-in induction cavity as a characteristic parameter for representing the magnetization field intensity characteristic of the magnetic core and by changing the charging voltage or the winding turn of a fast front edge pulse voltage generator, the hysteresis loop of the magnetic core under the fast pulse voltage with different characteristic parameters can be acquired through testing. The test device disclosed by the invention comprises a low-induction capacitor C, a fast pulse resistance voltage divider RD1 / RD2, a short-gap gas switch Gap, a primary winding, a secondary winding, a current coil and an outer cylinder. The test device can generate a fast front edge pulse voltage with the front edge being less than 20ns and the amplitude being 20-80kV and reaches the magnetization field intensity characteristic parameter value under actual working conditions of an FLTD (Fast Linear Transformer Driver) and an IVA (Ideal Voltage Amplifier).

The invention provides a crude oil electric dehydration high voltage power supply device, relates to crude oil electric dehydration high voltage power supply devices, and aims at solving the problems of continuous discharge of high voltage dehydration electrodes, collapse of high voltage dehydration electric fields and increasing of capacity requirement of the high voltage power supply devices during crude oil electric dehydration process. The crude oil electric dehydration high voltage power supply device performs pressure regulating and current-limiting on low voltage alternating current and then performs boosting through a high voltage transformer, two paths of high voltage outputs of the high voltage transformer are rectified by a first high voltage silicon stack and a second high voltage silicon stack, formed into high voltage direct current with positive polarity and negative polarity, and output to a high voltage fast pulse unit. A microprocessor control unit judges whether dehydration electrodes form ripples according to voltage and current monitoring values and controls switching of the high voltage fast pulse unit. Under a normal dehydration condition, the high voltage fast pulse unit outputs direct current with positive and negative polarity, and when short circuits are caused by existence of ripples, the high voltage fast pulse unit exerts batch-type high voltage large current pulse to load till the ripples are opened, and accordingly electric fields in a dehydration container are recovered. The crude oil electric dehydration high voltage power supply device is applied to the crude oil processing process.