161 results about "Parasitic oscillation" patented technology

The invention relates to a DC-DC power supply conversion device, in particular to a zero-voltage switch (ZVS) flyback-type DC-DC power supply conversion device with efficient conversion, efficient light-load conversion and low standby power consumption. An auxiliary switch and an absorption capacitor are additionally arranged on the flyback circuit; the auxiliary switch and the absorption capacitor are connected in series so as to form an auxiliary branch circuit; the auxiliary branch circuit can be connected in parallel to the two ends of the primary winding of a transformer or alternatively connected in parallel to the two ends of a primary-side switch; and the auxiliary switch is conductive for a determined period of time before the primary-side switch is conductive. Compared with the prior art, the energy of the circuit leakage inductor can be absorbed and transferred to the output terminal and a soft switch for realizing the primary-side switch, so that the invention can greatly improve the circuit efficiency; the parasitic oscillation caused by the leakage inductor can be suppressed, so that the EMI (electromagnetic interference) characteristics of the circuit can be improved; and the circuit can be controlled more easily, thereby improving the light-load circuit efficiency and reducing the idle-load energy loss.

A method and apparatus for plasma waste disposal of hazardous waste material, where the hazardous material is volatilized under vacuum inside a containment chamber to produce a pre-processed gas as input to a plasma furnace including a plasma-forming region in which a plasma-forming magnetic field is produced. The pre-processed gas is passed at low pressure and without circumvention through the plasma-forming region and is directly energized to an inductively coupled plasma state such that hazardous waste reactants included in the pre-processed gas are completely dissociated in transit through the plasma-forming region. Preferably, the plasma-forming region is shaped as a vacuum annulus and is dimensioned such that there is no bypass by which hazardous waste reactants in the pre-processed gas can circumvent the plasma-forming region. The plasma furnace is powered by a high frequency power supply outputting power at a fundamental frequency. The power supply contains parasitic power dissipation mechanisms to prevent non-fundamental, parasitic frequencies from destabilizing the fundamental frequency output power. These power loss mechanisms use either distributed resistance or frequency-selective power-loss devices to prevent parasitic oscillations from instantaneously turning on the high frequency power oscillator at non-fundamental frequencies.

An EUV light source of the present invention is capable of using a saturable absorber stably and continuously in a high heat load state. A saturable absorber (SA) device is disposed on a laser beam line to absorb feeble light, such as self-excited oscillation light, parasitic oscillation light or return light. SA gas from an SA gas cylinder and buffer gas from a buffer gas cylinder are mixed to be a mixed gas. The mixed gas is supplied to an SA gas cell via a supply pipeline, and absorbs the feeble light included in the laser beam. The mixed gas is exhausted via an exhaust pipeline, and is sent to a heat exchanger. The mixed gas, cooled down by a heat exchanger, is sent back to the SA gas cell by a circulation pump.

An oscillator circuit is disclosed which can be formed using discrete field-effect transistors (FETs), or as a complementary metal-oxide-semiconductor (CMOS) integrated circuit. The oscillator circuit utilizes a Pierce oscillator design with three inverter stages connected in series. A feedback resistor provided in a feedback loop about a second inverter stage provides an almost ideal inverting transconductance thereby allowing high-Q operation at the resonator-controlled frequency while suppressing a parasitic oscillation frequency that is inherent in a Pierce configuration using a “standard” triple inverter for the sustaining amplifier. The oscillator circuit, which operates in a range of 10–50 MHz, has applications for use as a clock in a microprocessor and can also be used for sensor applications.

An oscillation circuit including: a negative resistance element; a resonance circuit connected to the negative resistance element; and a stabilization circuit connected in parallel with the negative resistance element to suppress parasitic oscillation, wherein the stabilization circuit includes a variable shunt resistor and a adjusting device for adjusting the shunt resistor.

The invention discloses an underwater very low frequency (VLF) broadband sound source, which is composed of a shell, a vibration component, a guide component, a support and seal component, a magnetic circuit component, a seal and an electric interface. The underwater VLF broadband sound source is applied to the fields of underwater sound detection, marine geological prospecting, underwater target simulation and the like as a detection target or a test sound source. For the purpose of improving response flatness, broadening bandwidth, strengthening functional reliability, and increasing sound source level, in the underwater VLF broadband sound source, the vibration component is subjected to modality and quality control, thereby realizing light weight, large flexible rigidity and small parasitic oscillation; the working frequency lower limit of a system is reduced by flexible support, thus the working band is wider and flatter; the reliability of a coil and the fidelity of signals are improved by the guide device with limit and low friction; the magnetic driving force is improved by the twin-coil combination and the optimization of a strong-magnet closed magnetic circuit; and the underwater VLF broadband sound source is internally provided with a rubber air bag, thus being simple in structure, realizing self-adaption hydrostatic pressure compensation, and being convenient to use.

An oscillator configured to oscillate an electromagnetic wave, including: a negative resistance device; a microstrip resonator configured to determine an oscillation frequency of an electromagnetic wave excited by the negative resistance device; a resistance device and a capacitance device, which form a low-impedance circuit configured to suppress parasitic oscillation; and a strip conductor configured to connect the capacitance device of the low-impedance circuit and the microstrip resonator to each other, in which an inductance L of the strip conductor and a capacitance C of the microstrip resonator produce a resonance frequency of ½π√LC, and ¼ of an equivalent wavelength of the resonance frequency is larger than a distance between the negative resistance device and the resistance device of the low-impedance circuit via the strip conductor, is provided.

A balanced momentum probe holder in an apparatus for characterizing a sample surface has first and second members each having extensible and retractable distal ends. The distal ends extend or retract substantially simultaneously in response to a signal from a detector thus balancing the momentums of the first and second members and reducing the net momentum of the probe holder to essentially zero. Balancing the momentum of the probe holder reduces parasitic oscillations in the apparatus thus enhancing performance.

A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges using a substantially high index bonding elastomer or epoxy to a predetermined electromagnetic absorbing arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.

The invention relates to a DC-DC power supply conversion device, in particular to a zero-voltage switch (ZVS) flyback-type DC-DC power supply conversion device with efficient conversion, efficient light-load conversion and low standby power consumption. An auxiliary switch and an absorption capacitor are additionally arranged on the flyback circuit; the auxiliary switch and the absorption capacitor are connected in series so as to form an auxiliary branch circuit; the auxiliary branch circuit can be connected in parallel to the two ends of the primary winding of a transformer or alternativelyconnected in parallel to the two ends of a primary-side switch; and the auxiliary switch is conductive for a determined period of time before the primary-side switch is conductive. Compared with the prior art, the energy of the circuit leakage inductor can be absorbed and transferred to the output terminal and a soft switch for realizing the primary-side switch, so that the invention can greatly improve the circuit efficiency; the parasitic oscillation caused by the leakage inductor can be suppressed, so that the EMI (electromagnetic interference) characteristics of the circuit can be improved; and the circuit can be controlled more easily, thereby improving the light-load circuit efficiency and reducing the idle-load energy loss.

The invention relates to a method for inhibiting the amplified spontaneous emission of large-size sheet laser neodymium glass, which comprises the following steps of: (1) selecting absorbing glass matched with the sheet laser neodymium glass and an organic adhesive; (2) processing and adhering the sheet laser neodymium glass and an absorbing glass strip; (3) precisely polishing a light pass surface of the sheet laser neodymium glass, and the like. The method can effectively inhibit the amplified spontaneous emission and parasitic oscillation of the large-size sheet laser neodymium glass; gain performance approximates the theoretical calculation level; and the glass has high stability and meets the using requirement of a high-power laser device.

The invention discloses a transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with an active clamp and a modulation method thereof. The transformer-free type low-leakage-current photovoltaic grid-connected inverter circuit with the active clamp comprises two filter capacitors Cdc1, Cdc2, eight switch tubes S1, S2, S3, S4, S5, S6, S7, S8 and two filter inductors L1, L2, and is characterized in that an active switch tube is additionally arranged in the circuit so as to form a clamping unit, common-mode voltage in a grid-connected inductance follow current stage is clamped to the midpoint of a bus capacitor by being matched with an appropriate switching sequence, common-mode voltage disturbance of the system is removed, and thus a suspension problem of common-mode voltage of a decoupling inverter in zero level output is solved; and parasitic oscillation of a common-mode circuit is removed at the same time, and a phenomenon of common-mode resonance is suppressed. The photovoltaic grid-connected inverter circuit disclosed by the invention has the advantages of simple circuit structure, high efficiency, simple modulation method and the like. The photovoltaic grid-connected inverter circuit can ensure an inverter not to be affected by a current zero crossing point in unit power factor running, and can avoid current waveform distortion caused by influences of grid power fluctuations or operations at a non unit power factor.

An oscillator has a negative resistance element and a resonator along with a capacitor electrically connected in parallel with the negative resistance element relative to a power bias circuit, a capacitance of the capacitor being so selected as to suppress any parasitic oscillation due to the power bias circuit and allow oscillation at a resonance frequency due to the negative resistance element and the resonator.

This invention claims a novel radio frequency receiver system for selecting a digitally modulated carrier frequency, and more specifically a Zero Point, amplitude Modulated (ZPM) carrier frequency. ZPM modulation does not create side-band frequencies, thus allowing individual carriers to be very closely spaced. Traditional methods of frequency selection utilize resonant tuning circuits in the antenna circuit and following amplifier circuits. Resonant tuning circuits are the assemblage of inductors and capacitors that are subject to parasitic oscillations, harmonic oscillations, as well as environmental effects. While modern technology has sufficiently overcome these detriments for traditional radio communication, ZPM theory desires to tune to a single frequency carrier with only one cycle of difference between carriers. Obvious to those skilled in the art, this requires a non-traditional method. For ZPM carriers, all signal-handling circuits must be non or insignificantly reactive and process the signal in linear fashion throughout the receiver signal path. This invention accomplishes the required functions by a unique combination of standard integrated circuits and circuit components.

The invention discloses a two-way digital DC-DC convertor with a wide load range. The two-way digital DC-DC convertor comprises a high-voltage end, a low-voltage end, a dsPIC30F single chip microcomputer and a transformer. The output end of the dsPIC30F single chip microcomputer is connected with a drive circuit which is provided with a plurality of PWM output ends; the high-voltage end is connected with a high-voltage part rectifying circuit, the low-voltage end is connected with a low-voltage part rectifying circuit, and the transformer is arranged between the high-voltage part rectifying circuit and the low-voltage part rectifying circuit; the output end of the drive circuit is respectively connected to the control end of the high-voltage part rectifying circuit and the control end of the low-voltage part rectifying circuit. Dead time of phase-shifted full-bridge control is adjusted according to the magnitude of loads, meanwhile different rectification modes are selected according to the magnitude of the loads, and therefore the convertor has high efficiency within the wide load range. The convertor is provided with an active clamping circuit preventing vice edge parasitic oscillation, so voltage overshoot can be effectively prevented. Accordingly, the two-way convertor is especially suitable for occasions having a high requirement for efficiency of convertors and a requirement for large changes of the loads.

A high gain optical amplifier and method. Generally, the inventive amplifier includes a first crystal having an axis and a first index of refraction and a second crystal bonded to the first crystal about the axis and having a second index of refraction. The first index is higher than the second index such that light through the first crystal is totally internally reflected. In the illustrative embodiment, the first crystal is Yb:YAG with an index of approximately 1.82, the second crystal is Sapphire with an index of approximately 1.78, and the axis is the propagation axis. The invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large étendue. With a judicious choice of the laser crystal and cladding materials, shape, and bonding technique, the guided amplifier is much less susceptible to parasitic oscillation than amplifiers constructed in accordance with conventional teachings. The clad core is also able to handle larger thermal load without breakage than can an unclad core.

A wide load characteristic ZVZCS three-level DC-DC converter relates to a three-level converter. The aim of the invention is to settle the problems of large switching loss, generation of large voltage peak, easily switching tube damage and series electromagnetic interference problem existing in the prior three-level converter. The anode of a voltage source is simultaneously connected with one end of a first capacitor, one end of a fifth capacitor, a drain end of a first insulated-gate type field effect transistor, the cathode of a first diode, the cathode of a fifth diode and the collector electrode end of a fifth triode. The cathode of the voltage source is simultaneously connected with one end of a fourth capacitor, one end of the sixth capacitor, a source end of a fourth insulated-gate type field effect transistor, an anode of a fourth diode, an anode of a sixth diode and the emitter end of a sixth triode (S6). The wide load characteristic ZVZCS three-level DC-DC converter of the invention is also added with an auxiliary rectifying circuit and an active clamp circuit. The wide load characteristic ZVZCS three-level DC-DC converter of the invention has the advantages of high resetting speed of the primary side current, no overshoot voltage of the secondary side, etc. Furthermore the wide load characteristic ZVZCS three-level DC-DC converter of the invention settles the problems of duty ratio loss, primary side circumfluence, parasitic oscillation, etc. The efficiency of the converter is increased. The switching loss and the electromagnetic interference are reduced.

The invention provides a bonding edge-cladding method for laser glass, comprising the following steps of: finely selecting edge-cladding glass matched with the physical property of matrix laser glass, clearly cleaning an edge-cladding surface by the fine machining of the edge-cladding surface, directly gluing the matrix laser glass and the edge-cladding glass, putting into pre-prepared dies, bonding an edge-cladding interface by a specific heat treatment process without any organic and inorganic adhesives, and firmly combining the edge-cladding glass and the matrix glass, wherein the bonding and edge-cladding connection strength is approximate to the strength of the N31 neodymium glass per se. The method provided by the invention has the characteristics that the refractive index match is good, the bonding strength is high, the weather fastness is high, and the residual reflection of the edge-cladding interface is less than 4 / 10000, so that the requirement that the parasitic oscillation is eliminated by cladding edge can be completely met.

A glaze encapsulated solid-state laser component. The novel laser component includes a core and a cladding of ceramic glaze disposed on a surface of the core. In an illustrative embodiment, the core is fabricated from a laser gain medium and the cladding material is a multi-oxide eutectic ceramic glaze having a refractivity slighter lower than the refractivity of the gain medium, such that the glaze layer forms a step-index refractivity interface cladding that can effectively suppress parasitic oscillations in the core gain medium. The glaze cladding can be applied by coating the core with the glaze and then firing the glaze coated core, or by fabricating pre-formed cladding strips from the ceramic glaze in a first firing cycle, mounting the pre-formed strips to the core, and then fusing the pre-formed strips to the core in a secondary firing cycle.

The invention discloses a Boost resonant converter passive element integration device which comprises two PCB copper clad windings, two PCB integration windings, and two E magnetic cores. The two E magnetic cores are oppositely arranged. The two PCB copper clad windings are wound around the middle columns of the two E magnetic cores, and the two PCB integration windings are wound around the left and right side columns of the two E magnetic cores. Each of the two PCB integration windings comprises a PCB copper clad winding, a leakage inductance dielectric layer, a PCB copper clad winding, a dielectric layer, a PCB copper clad winding, a dielectric layer and a PCB copper clad winding orderly arranged from top to bottom. According to the device, a boost inductor, a resonant inductor, a transformer and a filter capacitor in a Boost resonant converter are integrated in a magnetic element, the number and size of the passive components are reduced, the power density of the Boost resonant converter is increased, and the influence of the parasitic oscillation of component distribution parameters on the performance of a circuit is weakened.

The invention relates to a method for suppressing parasitic oscillation in a gain medium of a grazing incidence plate strip. According to the method, a layer of dielectric material is plated on three non-light-through surfaces of the grazing incident plate strip, and the dielectric material shows the absorption characteristic on the parasitic oscillation of the gain medium. The method is simple and is wide in application range, and a better suppression effect on the parasitic oscillation is exerted. A plate strip crystal comprises six surfaces, the parasitic oscillation in the crystal can be enhanced by reflection or scattering of each surface, thus, an absorption medium is plated on all other surfaces except a pumping surface and a light through surface, and a parasitic oscillation loop is cut off to achieve an absorption effect. By the method, the parasitic oscillation of the gain medium with such structure can be effectively suppressed, the energy storage and the gain of the gain medium are improved, the amplified spontaneous radiation (ASE) of a system is reduced, and the output light pulse energy is improved. The method belongs to the technical field of laser.

An oscillator which oscillates electromagnetic waves includes a negative differential resistance element, a resonator configured to prescribe oscillation frequencies of the electromagnetic waves, a voltage modulation unit configured to modulate the negative differential resistance element, a stabilizing circuit configured to suppress parasitic oscillation, and a bias circuit, including a power supply and a line, used to control an operating point voltage of the negative differential resistance element. The voltage modulation unit is connected to the bias circuit through the stabilizing circuit.

A high gain optical amplifier and method. Generally, the inventive amplifier includes a first crystal having an axis and a first index of refraction and a second crystal bonded to the first crystal about the axis and having a second index of refraction. The first index is higher than the second index such that light through the first crystal is totally internally reflected. In the illustrative embodiment, the first crystal is Yb: YAG with an index of approximately 1.82, the second crystal is Sapphire with an index of approximately 1.78, and the axis is the propagation axis. The invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large étendue. With a judicious choice of the laser crystal and cladding materials, shape, and bonding technique, the guided amplifier is much less susceptible to parasitic oscillation than amplifiers constructed in accordance with conventional teachings. The clad core is also able to handle larger thermal load without breakage than can an unclad core.

The invention provides a solid laser amplifier capable of effectively inhibiting parasitic oscillation, which comprises a pumping system, a plug medium, and an enchantment structure; the side of the plus medium in the amplifier is a prism of which the angle is between 3 degrees and 5 degrees; a wrapping substance is coated outside the prism; and the selection scope of the wrapping substance is broad. The solid laser amplifier can effectively inhibiting parasitic oscillation, and has the advantages of simple structure, stable performances and easy manufacture.

The invention relates to an Er / Yb co-doped fiber for improving 1.5 mum laser efficiency, and is suitable for the laser communication field. The fiber comprises a fibre core, an inner wrapping layer, an outer wrapping layer and a coating layer from the inside out. The fibre core is formed by straight core and a section of spiral core; and fibre loss can be changed by adjusting spiral pitch of the spiral core and offset amount of a center shaft, and thus fibre loss in 1 mum wave band is allowed to be larger than fibre loss in 1.5 mum wave band. The features above allow the Er / Yb co-doped fiber to be applied to a high-power Er / Yb co-doped fiber laser, and thus the problem of 1 mum parasitic oscillation is effectively solved, and 1.5 mum laser output power is improved.

The invention provides a ytterbium-doped yttrium aluminium garnet multislab laser amplifier based on graded doping and cryogenic helium gas cooling. The laser amplifier includes a pump module, a coupling lens module, a dichroic mirror module and a gain medium module. The gain medium module adopts a combined slab graded-doping laser gain medium and is arranged perpendicular to the direction of the laser. The pump module includes a planar diode array pump source I and a planar diode array pump source II, which are respectively arranged on two sides of the gain module and used for pumping the end faces of the gain module. According to the invention, by means of the combined slab graded-doping laser gain medium, the varied-doping edge-package medium, the diode end face pumping and the cryogenic high-pressure helium active cooling, the amplified spontaneous emission is effectively reduced, the generation of the parasitic oscillation is prevented, the efficiency of the energy storage is improved, the generation of the waste heat is reduced, the temperature distribution in the medium is smoothed, and the effect of the heat management is further improved, so that the laser output of high repetition frequency, high-energy high-power and high light beam quality is achieved.

A glaze encapsulated solid-state laser component. The novel laser component includes a core and a cladding of ceramic glaze disposed on a surface of the core. In an illustrative embodiment, the core is fabricated from a laser gain medium and the cladding material is a multi-oxide eutectic ceramic glaze having a refractivity slighter lower than the refractivity of the gain medium, such that the glaze layer forms a step-index refractivity interface cladding that can effectively suppress parasitic oscillations in the core gain medium. The glaze cladding can be applied by coating the core with the glaze and then firing the glaze coated core, or by fabricating pre-formed cladding strips from the ceramic glaze in a first firing cycle, mounting the pre-formed strips to the core, and then fusing the pre-formed strips to the core in a secondary firing cycle.

The invention relates to a belt drive (1) comprising belt drive means (4) such as a belt or a chain and a plurality of wheels (1, 6, 7, 8), sitting on shafts and integrated into the drive, around which the belt drive is wound, parasitic oscillations being introduced into the belt drive (1) by means of at least one shaft. For the purpose of generating a counter-oscillation, at least one wheel (3) has a noncircular shape. Said noncircular wheel (3) is configured, in terms of its shape, in such a manner that it is adapted to generate a counter-oscillation which compensates at least two different main oscillation orders of the parasitic oscillation.

An oscillator has a negative resistance element and a resonator along with a capacitor electrically connected in parallel with the negative resistance element relative to a power bias circuit, a capacitance of the capacitor being so selected as to suppress any parasitic oscillation due to the power bias circuit and allow oscillation at a resonance frequency due to the negative resistance element and the resonator.

The invention relates to an inclined slab laser amplifier, which consists of a first stage amplifier, a second stage amplifier, a Dove prism, a first reflecting mirror and a second reflecting mirror; laser crystal slab strips of the first stage amplifier and the second stage amplifier are inclined laser crystal slab strips; each laser crystal slab strip comprises two end faces and four sides which are respectively called an end face A, an end face B, a pumping surface C, a pumping surface D, and two opposite cooling surfaces which are mutually parallel; and a minute angle is formed between the pumping surface C and the pumping surface D. The inclined slab laser amplifier effectively inhibits parasitic oscillation and improves laser efficiency; and the Dove prism effectively eliminates the optical beam gain and asymmetry of a thermal lens caused by thermal effect.