Showing papers on "Impulse generator published in 2018"

Investigation on Impulse Characteristic of Full-Scale Grounding Grid in Substation

Abstract: Impulse performance of grounding grid is needed for lightning protection design of power system. This paper describes an impulse test facility established for the full-scale grounding grid (50 m long and 52.5 m wide) in a 110 kV substation. Test method is presented, including configuration of current injection and return point, measurement of potential rise and longitudinal current. Impulse test is carried out with 2.6/50 and 8/20 μ s current waveform, and the maximum current amplitude is 4 kA. A Current Distribution, Electromagnetic fields, Grounding and Soil structure simulation for the tested grounding grid is also adopted. Impulse performance of full-scale grounding grid is affected by soil ionization and conductor inductance. There is steeper peak on the potential rise waveform near the injection point with shorter wave front current, which leads to more uneven potential rise distribution. Partial soil ionization could increase the current dispersing into the soil at partial area of the grounding grid, and the longitudinal current flowing to the next area decreases. These two factors pose a high potential difference hazard to the secondary equipment via the secondary cable.

Research on the detecting effectiveness of on-site lightning impulse test for GIS equipment with insulation defects

Abstract: On-site lightning impulse (LI) test waveform, restricted by the large load capacitance and impulse generator's inherent inductance, has a long wavefront time Tf compared with standard LI, called non-standard LI. The non-standard LI test has been carried out in the field. But its insulation defect detecting effectiveness is not clear. In this paper, a generating system of impulses with different waveform parameters, including double-exponential impulses with different wavefront times in the range of 0.08 ∼ 23.5 μs and an oscillating LI with wavefront time around 10 μs, was established. The insulation characteristics of SF6 gas gap with highly inhomogeneous electric field under impulses with different waveform parameters were investigated. Experimental results show that the insulation defects detecting effectiveness of oscillating LI with long Tf around 10 μs is lower than that of standard LI. Tf plays an important role in the insulation defects detection. With Tf increases, the 50% breakdown voltages for rod-plane gaps have an increased trend. The V-t curve presents a U-shape. Prospective voltage is introduced to evaluate the insulation defects detecting effectiveness. The prospective voltage-time characteristics confirm the conclusion that with the increase of impulse voltage Tf, the detection effectiveness for GIS insulation is reduced. The gap distance has influence on the shape of V-t curve. With distance increase, the 50% breakdown voltage of the gap is more sensitive to the wavefront time Tf and voltage rise rate dU/dt. Corona stabilization effect is not just in relationship with the rise rate of impulse, but also with electrode structure and gas pressure. The critical dU/dt for corona stabilization is calculated for different rod-plane gaps.

Design and Implementation of Surge Protective Device for Solar Panels

Abstract: Researchers for decades have utilized solar radiation as a sustainable renewable energy source. In this regard, Photovoltaic (PV) panels are satisfying the production of green energy and clean power. Frequently, these panels need to install on rooftops outdoor fields for maximum sun light feeding, thereby high-energy conversion to electricity. However, such PV systems installations are prone to direct or indirect lightning strikes. Herein, an impulse generator is designed to produce 750 V pulses for low voltage side to test the validity of our proposed surge protective device (SPD) as type-2. Moreover, the impulse generator provides 1.2/50μ $s$ and 8/20μ $s$ normalized voltage and current pulses, respectively. This approach controls the over-voltage caused by indirect lightening and thus protect solar panel systems. Furthermore, in the design of SPD, different components such as gas-discharge tube, transient voltage suppresser, metal oxide Varistor and Zener diodes are used to manage the impulse voltage at acceptable level. These results further highlighting the validity of implemented hardware.

Modeling and Construction of Marx Impulse Generator Based on Boost Converter Pulse-Forming Network

Abstract: This paper presents the design and construction of a sample of Marx pulsed generator based on boost converter (BC) pulse-forming networks (BCPFNs). BCPFN is used instead of the conventional Marx floors for constructing this pulsed generator. BCPFN is carried out by connecting inductors and capacitors in series and parallel modes, respectively, by using solid-state switches, and during this procedure the pulsed generator converts to BC temporarily and increases the voltage of capacitors uniformly to a considerable value. This technique causes an increase in the discharging voltage level to the load that is many times more than its dc voltage source by charging the capacitors to a greater level. In order to take advantage of the benefits of Marx generator and PFN, this paper suggests a new circuit with the minimum number of switches. It means, to compose BCPFN and Marx, we have tried to design the circuit with fewer switches and instead of it we have achieved our desired performance with changing the operating mode in the states of BC, PFN, BCPFN, and BCPFN Marx. The results are simulated with MATLAB software. At the end, the experimental results of the construction of the above-mentioned system at low-power levels are presented, and the topology’s accuracy is proved by comparing them to the results of simulation.

Special HVDC circuit lightning shielding analogue test platform

Abstract: The utility model discloses a special HVDC circuit lightning shielding analogue test platform, including DC power supply, experimental major loop and observation system, experimental major loop includes that impulse generator, high tension lead, high -voltage rod electrode, shaft tower model, overhead ground wire, transmission pressure, insulator chain and ground connection iron net observation system include divider, oscilloscope and take the photograph camera, the divider is parallelly connected with impulse generator to the input that allies oneself with links to each other with ground connection iron net, and parallelly connected output passes through coaxial cable and links to each other with oscilloscope, impulse generator passes through the high tension lead and links to each otherwith the high -voltage rod electrode, it arranges experimental major loop side in and aims at the transmission pressure to take the photograph camera. This device can disclose the the discharge process that special high voltage transmission lines suffered the thunderbolt, accurate aassessment ultra -high voltage transmission line way thunder and lightning shielding property, and through carrying out special HVDC circuit lightning shielding analogue test, special HVDC circuit lightning protection ability provides the theory and data support for research promotes.

Very fast high voltage impulse generator

Abstract: Some high voltage applications use very fast impulses with rise time less than 100 nanoseconds. Measurements of these impulses are difficult, and a lot of different voltage dividers are used. In many cases, inadequate metrological support of calibrations of these dividers is a problem. In recent years, an etalon for very fast high voltage impulses is missing in the Czech Republic. The future aim of our work is the realization of such a reference divider. However, in the first step, it is necessary to develop suitable very fast high voltage generator, which is the subject of this paper. Realization of a stable very fast high voltage impulse generator with light and relatively low cost construction, and with rise time less than 100 nanosecond, at a voltage level of the order of 100 kV, into a capacitive load representing e.g. tested insulator, is not possible with design of common commercial impulse generators. An important part of the paper is a design of electrical circuit of the very fast impulse generator with a numerical simulation which has done limit parameters of all components of the device. Finally, the impulse generator for voltage up to 100 kilovolts and a rise time less than 50 nanoseconds has been realized. The results of verification measurements in case of two different types of voltage dividers are presented in this paper.

Investigating the lightning resistance of composite materials for ensuring safe operation of transport infrastructure facilities

Abstract: The article reviews a destructive effect of the lightning current impulse on composite materials widely used in automotive, power and aerospace industries. It is argued and substantiated that it is improper to use a standard impulse simulating the effect of a lightning strike. For better simulation of lightning current effect, results of experiments with regard to lightning strike current, performed at the Santis tower (Switzerland), in the course of which a "slow" part of lightning strike was discovered (besides the "fast" one), are used. An approach to create a generator of current impulses with waveforms similar to those recorded during full-scale experiments is presented. Two options of the impulse generator are compared: a generator with an accumulating inductor and a two-stage generator with preliminary separate charging of the “quick” and “slow” stages. The authors opt for the latter. Test results with regard to the selected option, confirming that generated current impulses are similar to those obtained during full-scale experiments, are presented. Results of specimen destruction with current impulses of various waveforms are provided. It is shown that current impulses with waveforms similar to those recorded during full-scale experiments cause more destruction to composite materials than standard impulses. The necessity to perform lightning resistance tests regarding composite materials, used to manufacture systems and devices for the transport industry, in terms of the effect of current impulses with waveforms similar to those recorded during full-scale experiments, is acknowledged.

Challenges resulting from the use of spark gaps for superimposed voltage tests

Abstract: Suitable testing techniques are required to ensure reliable operation of novel HVDC equipment. For instance, HVDC cables and their accessories as well as HVDC GIS/GIL are required to undergo a superimposed voltage test where the test object is stressed simultaneously with a DC voltage and an impulse voltage (LI/SI). In this respect the mutual influence of the voltage generators needs to be considered. Usually a blocking spark gap or a blocking capacitor is used to protect the impulse generator from DC stress. While there are no major challenges associated with the latter, spark gaps oftentimes cause deviations of the standardized voltage waveforms. Depending on the type of impulse voltage the impulse's front, tail or even both can be distorted heavily which will be illustrated in this contribution. Additionally, the underlying phenomena will be discussed.

Electromagnetic interference shielding in unmanned aerial vehicle against lightning strike

Abstract: Electromagnetic interference (EMI) due to lightning strike in Unmanned Aerial Vehicle (UAV) became a critical issue, since it could cause a severe damaged to electronic equipment which was installed in UAV. This paper proposed a method to reduce EMI by creating shield over the body of UAV with aluminum foil with thickness 0.15mm. A standard lightning impulse-voltage generated by impulse generator was delivered to the high voltage (HV) electrode at a particular distance from UAV. Indirect effect of lightning strike was investigated by measuring induced voltage inside the compartment of UAV fuselage during flashover between the HV electrode and UAV. Flashover between the HV electrode and UAV simulated the lightning strike. The result showed that the highest voltage only 1V at UAV compartment when 150kV impulse voltage supplied to the electrode with striking area on the wing. The measured voltage was far below 100V as the insulation level of low voltage equipment inside UAV. Although the direct effect of lightning has created a burning hole on the surface aluminum foil with thickness 0.15mm, the effect was overcome by increasing the thickness to 0.3mm. The application of aluminum foil over the surface of UAV repelled the electromagnetic interference which acted as a Faraday cage. The shielding method was successfully reduced the effect of EMI.

Subway rail real -time status monitoring devices

Abstract: The utility model discloses a subway rail real -time status monitoring devices, include and closely paste sensing fiber and narrow linewidth lasers ware, light pulse modulator, polarization controller, circulator, impulse generator, WDM system, the brillouin scattering distributed optical fiber sensor who lays, the intelligent terminal who is used for data processing along rail line, adopt many reference amounts distributed optical fiber sensor to combine sensing fiber closely to paste along rail line and lay, to subway steel rail temperature, meet an emergency and characteristic parameter distribution formula collection such as vibration, realize monitoring of safe states and early warning such as track temperature, stress, reach orbital motion safety condition assessment's purpose

Impulse Characteristics of Earth Electrodes in Different Soil Resistivity by Field Measurements

Abstract: This paper presents the findings on the impulse characteristics of three types of soil by field measurements. A $\mathbf{2m}\ \mathbf{x}\ \mathbf{2m}$ grounding grid was installed for each site and was tested with 300kV, 10kA impulse generator. It was found that the resistance of low resistivity soil was found to be constant, and the resistance of high resistivity decreased with increasing current magnitudes. It is hoped that more effective earthing systems can be obtained in future, whereby taking consideration of the ionisation process in the soil in the design of earthing systems.

Electromagnetic Radiation Distribution in a High Voltage Test Environment

Abstract: The transient electric and magnetic fields radiated by the discharge of a high voltage impulse generator have well-known effects of creating serious interferences with the measuring and recording equipment. These effects may result in the mis-operation, or in the worst case, may damage the electronic circuitry of the measuring system. Measurements were performed to investigate the characteristics and distribution of electric and magnetic field components originating from the operation of a 3MV impulse generator. E-Field and H-Field were simultaneously recorded and measured independently. D-dot probes measuring the time rate of change of electrical displacement and loop probes observing the time rate of change of magnetic fields were used. The electromagnetic interferences in the vicinity of the impulse generator and control room and the dependence of these interferences on the charging voltage of the generator, elevation, and type of connection arrangements are investigated. The results and discussions from this study can be used for the cost-effective electromagnetic shielding of sensitive measurement equipment in large high voltage laboratories.

Marx Generators and Marx‐Like Circuits

Abstract: The simplest and most widely used high‐voltage impulse generator is the device Erwin Marx introduced in 1925 for testing high‐voltage components and equipment for the emerging power industry. This chapter discusses the principles of operation and overall performance of Marx generators. For instruction, the design formulas for simple Marx generators based on their equivalent circuits are given in considerable detail. A fully erected Marx generator is essentially a capacitive discharge. Thus, the load voltage depends not only on the characteristics of the Marx but also on the characteristics of the load. The chapter highlights some aspects in the discussion of modified Marx configurations. It reviews the importance of overvoltages to Marx operation, as well as advanced triggering techniques. The chapter also discusses various aspects of Marx generators such as electrical insulation, delay time and jitter, and the selection of components.

Range detecting device based on single photon avalanche diode

Abstract: The utility model provides a range detecting device based on single photon avalanche diode. It includes: the array is referred to to single photon avalanche diode, is configured as to be used for receiving the light that comes from the light source via inside coupling path, single photon avalanche diode returns the array, is configured as to be used for receiving the light that comes from this light source via outside free space route, calibration impulse generator is configured as and is used for generating calibration signal transmitter, the playback circuit system is configured as and is used for the receipt: this refers to the output of array via the reference signal route, should return the output of array via the backward signal route, and should calibrate impulse generator via the output in calibrating signal route, and this calibrating signal route is including the the first signal route of following this reference signal route basically, and wherein this playback circuit system is configured as and is used for exporting the delay difference between this reference signal route of sureness and this the backward signal route based on this calibration impulse generator via this of this calibrating signal route.

Tesla's pulse source that steps up

Abstract: The utility model provides a tesla's pulse source that steps up, is including the impulse generator that connects gradually, tesla transformer, peaking electric capacity, puncture switch, radiation orconduction injector certainly, its characterized in that, the pulse that produces of impulse generator charge for through the tesla transformer steps up after peaking electric capacity, the peaking capacitance voltage punctures the switch conduction after rising certain numerical value certainly, conveys high voltage pulse for radiation or conduction injector, the switch of puncture certainly, seal support housing, solid fixed electrode, adjustable electrode, oil medium and the two -layer combination insulating medium of gas medium including cylindric insulation, the realization endures the high voltage and the reduction switches on the inductance, changes the impulse waveform forward position suddenly. The utility model discloses make to produce high voltage pulse simply, reliably, and reduce cost.

E-band Impulse Radio Transceiver with 2-Bit Pulse-Position Modulation

Abstract: This paper presents a novel impulse radio transceiver based on a 2-bit pulse-position modulation (PPM) system for E-band wireless communication systems. We propose a time-based modulation architecture for a wireless transceiver. This is a promising architecture for deep-submicron and nanoscale CMOS technology. The performance of the wireless transceiver can be enhanced as the speed of the CMOS circuit increases. The transmitter is composed of four circuit blocks: a pulse-position modulator, impulse generator, millimeter-wave bandpass filter, and power amplifier. The receiver is comprised of a conventional quadrature demodulator. The transmitter and receiver chipset is fabricated in 55-nm standard CMOS technology. In transceiver loop-back tests, a data rate of 7.0 Gb/s with repetition data and 4.6 Gb/s with pseudo-random bit sequence (PRBS) data are demonstrated.

A impulse generator in pit that is arranged in wireless following to bore measurement system

Abstract: The utility model belongs to the measurement system field is bored in following of oil field development in -process, especially relates to an impulse generator in pit that is arranged in wireless following to bore measurement system, including barrel, motor, holding ring, last valve body, lower valve body, still include miniature turbogenerator, battery and charge controller, the upper end of barrel have the top connection through threaded connection, accompany a ring carrier between top connection and the barrel, miniature turbogenerator pass through the gusset and fix the center at ring carrier, motor, battery and charge controller all install in a waterproof sealing casing, the output shaft of motor is connected with the valve face of last valve body after passing the waterproof sealing casing. The utility model discloses set up miniature turbogenerator, charge controller and battery in impulse generator, can charge to the battery through miniature turbogenerator to guarantee the continual and steady power supply of motor.

Electromagnet control circuit

Abstract: The utility model provides an electromagnet control circuit which characterized in that: including burden impulse generator, delay controller, reverse shaping circuit and the drive circuit who is usedfor controlling electro -magnet work, burden impulse generator's output is connected with delay controller's input, delay controller's output is connected with reverse shaping circuit's input, reverse shaping circuit has first reversion and exports control signal terminal and the reverse control signal terminal that exports of second, drive circuit has a drive circuit and has the 2nd drive circuit of reduction voltage circuit, reverse shaping circuit's first reversion exports control signal terminal and exports control signal terminal with the second reversion and connect a drive circuit's input and the 2nd drive circuit's input respectively. It works under the operating voltage of difference to adopt above -mentioned circuit to enable the electro -magnet to realize that reduced voltage keeps at operating condition in order to maintain the electro -magnet, thereby reduce system power dissipation, reduced the damage that the electro -magnet caused because of generating heat, and wholecontrol circuit is simple, the preparation is convenient, and is with low costs.

Handheld operational unit device of connecting numerical control system controller through bus interface

Abstract: The utility model discloses a handheld operational unit device of connecting numerical control system controller through bus interface, comprises a processo, bee calling organ, a display uni, the operation button, power supply circuit module, the bus interface chip, rotatory impulse generator handles the chip, rotatory impulse generator, the numerical control system controller, it is more powerfulthan conventional handheld operational unit function to hand the operational unit device, all information that can show the lathe through the demonstration screen display on the handheld operationalunit, can show the button state through the led on the handheld operational unit, can be through all operations of button operation lathe, owing to be through bus connection transmitting data, the operation button can be expanded wantonly, the machine tool operation button that even can direct replacement falls numerical control system itself, it is many to have solved conventional hand wheel cable, the fault rate is high, the shortcoming of function singleness

Numerical Computational Analysis of Lightning Energy Storage System Using Single Stage Two Level Impulse Generator

Abstract: Due to very intermittent properties of lightning strike and also hazards involved within it, very limited research has been conducted in Lightning energy harnessing area worldwide. However, the lightning causing clouds have very high charge density. So, an experimental study in numerical computational environment has been experimented for measuring the response characteristics of lightning spark to store the energy by real time environmental data collected from various meteorological center. The single stage two level spark generator circuit has been used to simulate the presented system. Also, this paper presents an analytical and experimental response of five level inverter integrated with supercapacitor to store lightning energy within supercapacitor and to convert it into AC voltage for various loads. Through this presented paper an imitated response has been shown of PMSM and Grid Load connected with storage and conversion system.

Downhole while-drilling gas-logging testing device

Abstract: The invention provides a downhole while-drilling gas-logging testing device comprising a hydraulic module, a gas detecting module, a control module and a mud impulse generator. Through moving of a piston in the hydraulic module, annulus drilling fluid flows into the hydraulic module, the gas detecting module measures the content of methane gas in the annulus drilling fluid, and the concentration of the methane gas in a stratum is determined according to the measurement value; gas concentration data are transmitted to the control module, the control module processes the data transmitted by thegas detecting module and transmits the data needing to be uploaded to a ground system to the mud impulse generator, and the mud impulse generator converts data signals needing to be uploaded to the ground system into mud impulse signals and transmits the mud impulse signals to the ground system; and the ground system interprets the mud impulse signals and then obtains the uploaded data. Accordingto the downhole while-drilling gas-logging testing device, downhole gas parameter detection can be achieved in real time and online, and the accuracy of a tested result is improved.

Discussion of Measurement Methods of Impulse Grounding Impedance

Abstract: The grounding device is very important for lightning protection. However, it is difficult to measure the impulse grounding impedance because the impulse generator is cumbersome and dangerous compared with the device for power frequency test. At the same time it is difficult to generate a lightning current with a suitable waveform due to the inductance of the long current lead. In this paper, two methods to measure the impulse grounding impedance were carried out at an outdoor test site. One was the traditional fallof-potential method, another was a method with a grounding ring surrounding the grounding device as the current return pole. The test results of both methods were presented and the characteristics of each method were discussed. It was found that for the method that uses a ring surrounding the grounding device as the current return pole, the measured impulse grounding impedance was always smaller than the results by fall-of-potential method. However, it could obtain the ground potential gradients near the grounding device.

High accuracy integrated form is wireless along with boring measurement system

Abstract: The utility model provides a high accuracy integrated form is wireless along with boring measurement system, including terrestrial system, system and underground power supply system in the pit, the system is including visiting pipe, impulse generator, gamma measuring apparatu and resistivity measuring instrument in the pit, visit the pipe including measuring nipple joint, circuit module, it includes measuring unit and sensor to measure the nipple joint, the terrestrial system includes riser pressure sensor, data processing appearance, driller's display, computer software system, the system adopts the multiplexing single bus -mode topological structure of signal power in the pit, underground power supply system adopts the high -power generator 650MWD dabber. The beneficial effects of the utility model are that: the measuring data of instrument are more accurate, reliable, the circuit is simple, response speed is fast, the filtering effect has been optimized.

Pipe network cleaning device

Abstract: The utility model provides a pipe network cleaning device, includes the outer container, the inside of outer container is equipped with control panel, air compressor, impulse generator and control module, last display screen, gas input interface, water input interface, pulse output interface and the USB data interface of being equipped with of control panel, control module includes central processing unit, memory and wireless chip, central processing unit is connected storage, wireless chip, control panel, first solenoid valve, second solenoid valve, air compressor and impulse generator respectively The utility model provides a pipe network cleaning device possesses remote control function, convenient operation, and adopt pulse cleaning technology, do not harm the pipeline, do not use thechemical cleaning agent, it is pollution -free to the environment

Indoor environment regulation and control system based on light moxibustion health care

Abstract: The utility model discloses an indoor environment regulation and control system based on light moxibustion health care, including MCU controller, intelligence switch, intelligent temperature controller, impulse generator, anion generator and infrared heating element far away, the infrared heating element array far away that infrared heating element far away formed sets up in at least one inner wall of the interior space, infrared heating element far away with intelligent temperature controller connects, intelligent temperature controller passes through intelligence switch with the MCU controller is connected, impulse generator with the MCU controller is connected, the drive intelligent temperature controller, it is a plurality of anion generator sets up in the interior space, anion generator passes through intelligence switch with the MCU controller is connected. The utility model discloses it is integrated in the interior space to be bare the moxibustion technique, is including that human main playground such as house, office makes up the environment of useful health, has smooth moxibustion health function simultaneously.

System for be used for data transmission that logs well

Abstract: The utility model discloses a system for be used for data transmission that logs well, including detection sensor, coding module, impulse generator, mud pipe way, pressure sensor and the decoder module who connects gradually, the coding module divides into groups the detection sensor measuring original data of institute and encode to produce the modulation waveform drive pulse generator, the pressure waveform that impulse generator changes in mud pipe says, pressure sensor installs the ground section of saying at mud pipe, gathers the pressure waveform who transmits through the mud pipe way and inputs decoder module. The utility model discloses utilize the frame structure of many parameter sequence and CRC check -up, can obviously improve the signal quality, subsequent processing of decoding of being convenient for.

Synchronous trigger device of many switches of impulse generator

Abstract: The utility model provides a synchronous trigger device of many switches of impulse generator, wherein, the device is including charging source, output and impulse voltage generating circuit. Adjustable its length of coaxial cable among the impulse voltage generating circuit triggers resistance for substitutional resistance not to load capacitance can change the adjustment and in order to reach the adjustment output waveform, guarantee the purpose that triggers in step of switch. Through the adjustment synchronous trigger device's synchronous parameter is confirmed in the difference the test that the impulse generator output produced under the synchronous parameter triggers the wave form, the rethread contrast the test triggers the wave form and triggers the wave form with the standard towhether determine output's wave form accords with the waveform output requirement. The application provides a device can pass through to change the mode of synchronous parameter, thereby realizes triggering in step of a plurality of switches and export the wave form that triggers of ideal, solves the problem that a plurality of switches of traditional impulse generator can not trigger in step.

Power frequency continuous current test device's control survey circuit

Abstract: The utility model provides a power frequency continuous current test device's control survey circuit belongs to the power equipment control survey field. This control survey circuit includes: measuring circuit, signal conditioning circuit, control circuit and controller once incline, the measuring circuit that once inclines is used for gathering measuring -signal from the circuit that once inclines, transmits measuring -signal to signal conditioning circuit, signal conditioning circuit is used for carrying out signal conditioning and digital analog conversion to measuring -signal, and the measuring -signal after will changing transmits to the controller, the controller is used for according to the measuring -signal after the conversion, and to control circuit output control signal, the impulse generator who is triggered in the circuit that once inclines by control circuit produces the impulse overvoltage, wherein, control circuit, signal conditioning circuit and controller are respectively by voltage power supply all the way, mutual isolation between each way voltage. The utility model discloses the impulse overvoltage that the impulse generator in the circuit of can effectively preventing once to incline produced causes the harm to power frequency continuous current test device's control survey circuit.

Prevent impulse generator of jam

Abstract: The utility model belongs to the technical field of the impulse generator technique and specifically relates to indicate a prevent impulse generator of jam, which comprises an outer shell, the shell is provided with the feed liquor hole and goes out the liquid hole, go out the downthehole pulse control valve that has installed of liquid, still including direction core valve, the pulse valve head,piece and filtering component reset, the pulse valve head slides and sets up in direction core valve, filtering component's one end butt in the one end of pulse valve head, filtering component is provided with the first filtration pore of crossing with feed liquor hole intercommunication, direction core valve is provided with first water conservancy diversion hole and bar hole, the pulse valve head forms confined holding cavity with direction core valve, holding cavity and bar hole intercommunication. The utility model discloses a mud that the bar pore pair got into in the holding cavity carries out secondary filter, and in the silt of avoiding the large granule got into holding cavity, the silt that prevents the large granule was difficult to discharge and causes sediment accumulation inholding cavity or block up the bar hole, and dead phenomenon can not appear blockking up or blocking in impulse generator, and has prolonged impulse generator's life.

A 7–9 GHz UWB Radar Sensor Module with Single Chip Radar IC and On-Board Antenna

Abstract: A 7–9 GHz UWB radar sensor module using single chip radar CMOS IC and on-board UWB antenna is presented. To reduce the size and power consumption, a single chip CMOS UWB radar IC is implemented. For the reliable and low power radar, the envelope detection architecture is used at the expense of short detection range. The equivalent time sampling technique is adopted for UWB radar IC, employing delay locked loop and digitally synthesized impulse generator with 0.5 ns resolution. On-board $2\times 2$ patch antenna is embedded on radar board. The center frequency and bandwidth can be tuned and the human target detection range is up to 6.3 m. The chip size is $\mathbf{2.8 \ mm\times 2} \mathbf{mm}$, and current consumption is 122 mA at 1.2 V supply.