A study of the switching of the microwave compressor switch in a circular waveguide

Results of the experimental study of the interference switch for the H ₁₁ mode in a circular 10-cm-wavelength waveguide are presented. The conditions required for efficient microwave discharge switching of the interference switch are determined. The results of the study of the switching process allowed us to design and produce an interference switch with better characteristics than those of rectangular waveguides. It is shown that this switch extracts the stored energy from the microwave compressor cavity more efficiently and improves the amplitude stability of the output pulse radiation.     

Studying dynistor switches with nanosecond switching times

The results of studying the process of switching deep-level dynistors (DLDs) with 16- and 24-mm-diameter structures in the modes of switching micro- and nanosecond pulses with amplitudes of several kiloamperes are presented. It is shown that the dynistor switching process is highly uniform. The results of DLD tests at a high repetition rate of switched current pulses are presented. The principle of constructing high-power DLD switches with independent triggering of dynistors, which is based on the use of a single-turn saturable-core choke in the power circuit and a saturable-core isolating transformer in the DLD triggering circuits, is described. A DLD switch with an operating voltage of 8 kV is considered, which can switch current pulses at a frequency of 2 kHz with an amplitude of 1.5 kA and a duration of 200 ns.     

A compact semiconductor opening swith-based generator with a 300-kV output voltage and up to 2-kHz pulse repetition rate

A compact generator with a semiconductor opening switch (SOS-diode) shaping across resistive load pulses with an amplitude of up to 300 kV, duration of 30–50 ns, and a 300-Hz pulse repetition under uninterrupted operation and up to 2 kHz in a 30-s burst mode is described. The generator contains a thyristor charging device, magnetic compressor, and inductive storage with a semiconductor opening swith based on SOS-diodes. The average output power at a maximum pulse repetition rate and a 250kV-voltage is 16 kW. The overall dimensions of the generator are 0.85×0.65×0.42 m, the weight is about 115 kg.     

A photoreactor on the basis of a Xe2 excilamp

A photoreactor developed on the basis of a Xe₂ excilamp with a power of ～10 W (with a power density of 15 mW/cm² emitted from a surface of ～700 cm²), which can operate in liquids and gases at a pressure of up to 40 atm, and a multifunctional cell with an active volume of ～760 cm³ is described. Data on water photolysis in a natural gas exposed to VUV radiation with λ=172 nm are presented.     

An Electrical-Explosion Opening Switch Powered from a Magnetic-Explosion Generator

The results from experiments with powering an electrical-explosion opening switch (EEOS) from a high-speed helical magnetic explosion generator are presented. The energy capacity of this generator is ∼1 kJ, the total operating time is 25 μs, and the characteristic current rise time is ∼2 μs. In experiments with thin copper wires used in EEOSs, voltage pulses with an amplitude of ∼180 kV and a rise time of ∼50 ns were formed across a 25-Ω resistive load connected in parallel to the EEOS. __________ Translated from Pribory i Tekhnika Eksperimenta, No. 5, 2005, pp. 75–80. Original Russian Text Copyright ? 2005 by Demidov, Boriskin, Stepanov, Konovalov, Kazakov, Shibalko, Vlasov, Yanenko, Rozhnov, Golosov, Shapovalov, Shuvalov.     

A High-Current Vacuum Closing Switch

A high-power pulsed vacuum closing switch is described. The switch consists of several vacuum diodes with narrow gaps (1 mm) connected in series. The switch closing time (10 ns) is determined by the time of the short-circuiting of this diode by a plasma in the near-electrode regions. The switch closing rate and the values of the switched currents and voltages are estimated. The results of experiments in a test bench circuit are presented. The switch can be used in pulsed power technology to solve such problems as voltage-pulse front sharpening and trailing-edge cutting, the short-circuiting of the reflected pulse, etc.     

Operating features of a high-voltage spark gap switch with gas blow normal to the breakdown path in a repetitively pulsed mode

The results of studies of a high-voltage two-electrode spark gap switch (SGS) with forced gas blow at an operation voltage of up to 1.2 MV are presented. An SGS filled with nitrogen as the working gas at a pressure of up to 16 atm operated as the high-voltage switch of a high-current nanosecond electron accelerator. The gas flow was directed normally to the breakdown path. The SGS switched a 50-Ω forming line with an electrical length of 10 ns to a matched load. The voltage rise time across the electrodes before breakdown was ～25µs. A stable repetitively pulsed mode is realized at operating voltages of 100–680 kV and pulse repetition rates of up to 270 Hz with a standard deviation of the pulse breakdown voltage of ≤1%. The physical mechanisms that determine unstable operation of the device during self-breakdown are analyzed.     

A nanosecond SOS-generator with a 20-kHz pulse repetition rate

A nanosecond SOS-generator with a 20-kHz pulse repetition rate in the continuous operating mode and with a 100-kHz pulse repetition rate in the pulse burst mode is described. The generator contains a low-voltage module with a primary capacitive storage and a transistor switch, and a high-voltage module with a magnetic compressor and a semiconductor opening switch (SOS diode). The generator forms pulses with amplitudes of 40–100 kV with a 20- to 30-MW peak power and a 10- to 14-ns duration across a 50- to 500-Ω external load. The output average power in the continuous operating mode is 5 kW. The electric circuit, principle of operation, and design of the generator’s elements are described. The test results are given.     

A compact high-voltage pulse generator with opening insulated-gate bipolar transistor switch and a high pulse repetition rate

A small-size high-voltage (～20 kV) microsecond pulse generator, which is based on a pulse transformer and loaded into a reactor with a pulse corona discharge, is described. Insulated-gate bipolar transistors (IGBTs) that form the switch are used in the low-voltage circuit of the generator. When the switch is open, voltage pulses with an amplitude of up to 1000 V are created across it and, hence, across the primary winding of the transformer. The pulse repetition rate of the generator is ～20000 pulses/s.     

Small switches of high-power microsecond pulses on the basis of high-voltage integrated pulse thyristors and reverse switch-on dynistors

A high-voltage switch on the basis of a small unit of series-connected high-voltage integrated pulse thyristors (HVIPTs), which were developed at the Ioffe Physical Technical Institute, was designed and investigated. At a power voltage of 25 kV, current pulses of microsecond duration with an amplitude of 2.8 kA and a rise time of 0.8 μs were switched. The attained current density through an HVIPT (5.6 kA/cm²) appreciably exceeds the permissible current density for conventional thyristors. It is shown that the developed HVIPT unit can be used in the triggering circuit of a high-power assembly of reverse switch-on dynistors (RSDs) at an operating voltage of 25 kV, which consists of 14 series-connected dynistors with a diameter of their structures of 24 mm. The RSD switch with a triggering circuit on the basis of HVIPTs allowed switching of rapidly rising current pulses with an amplitude of 20 kA and a duration of 150 μs. The small dimensions of the HVIPT unit (4 × 10 × 32 cm) and the RSD assembly (7 × 7 × 34 cm) determine the wide prospects for using them in high-power pulse technology.     

A low-impedance high-voltage bipolar pulse former

The results on the formation of bipolar pulses with amplitudes of up to 100 kV, a duration of 2 ns, and a pulse repetition rate of 100 Hz across a 12.5-Ω load are presented. Lines with a characteristic impedance of 6.25 Ω were switched using multichannel ring switches with 70-mm-diameter electrodes in a nitrogen medium at a pressure of 40–60 atm. At a pressure of 40 atm, the rms deviation of the operation time of the sharpening switch reaches 40 ps at a voltage-pulse rise rate of 7 × 10¹³ V/s at the electrodes. As the pressure increases, the stability of the output bipolar pulses deteriorates; this is probably associated with a disturbance of the multichannel-switching mode in the sharpening switch. The performed simulation of the pulse-former operation showed that the energy loss in the switches reaches 40% of the stored energy in the output line of the Sinus-160 generator.     

Reverse switch-on dynistor switches of gigawatt-power microsecond pulses

A high-power (150 kA and 16 kV) small switch based on an assembly of reverse switch-on dynistors (RSDs) connected in series and a coaxial saturable-core choke, which creates conditions for their efficient switching, is described. An essential feature of this switch is a drastic reduction of the duration of the control action, as a result of which minimum dimensions and a low inductance of the saturable-core choke are ensured at a high (25 kA/μs) rise rate of the switched current. Increases in the control-current amplitude and rise rate that are required for maintaining the triggering charge at a constant level are attained thanks to the use of a fast-acting switch based on new semiconductor devices—deep-level dynistors—in the RSD-control circuit.     

A High-Current Pulse Generator SIGNAL with an Inductive Energy Storage and a Microsecond Plasma Opening Switch

The primary energy storage in the SIGNAL installation is a 4.7-F capacitor bank with a stored energy of up to 24 kJ switched by a gas-discharge gap switch of the trigatron type. The plasma source and the design of the microsecond plasma opening switch ensure current flow through this switch and inductive storage for a time of up to 1.7 s. The current amplitude reaches 330 kA. The current switched to the load is 20–300 kA in various modes with a rise time of 10–200 ns. The voltage across the feedthrough insulator reaches 400 kV. The installation is used in experimental studies of linear pinches, capillary discharge, and microsecond plasma opening switches.     

A Switch Based on Reverse Switch-on Dynistors with a Diode Sharpener of Switched Current Pulses

A principle of constructing a combined semiconductor switch based on a diode assembly and an assembly of reverse switch-on dynistors (RSDs) is considered. The diode assembly serves as a sharpener of current pulses switched by the RSD assembly. The results of tests of a combined switch, which forms 3.5-kV voltage pulses with a duration of 1 s and a rise time of 10 ns at a load of 10 , are presented. Ways of enhancing the switching capabilities of RSD switches with diode sharpeners are presented.     

Sufficient condition for stabilization of linear time invariant fractional order switched systems and variable structure control stabilizers

This paper presents the stabilization problem of a linear time invariant fractional order (LTI-FO) switched system with order 1相似文献   

A switched supply tunable red-green-blue light emitting diode driver

This paper presents a new switched supply tunable red-green-blue (RGB) light emitting diode (LED) driver. The RGB LEDs act not only as light emitting devices but also as rectifying diodes in the presented driver circuit. The RGB LED color control is realized by controlling the switched supply voltage amplitude, frequency, and duty cycle. The driver efficiency is high since the only loss in the driver circuit is the switch and can be further reduced by direct alternate current supply.     

Bipolar high-repetition-rate high-voltage nanosecond pulser

The pulser designed is mainly used for producing corona plasma in waste water treatment system. Also its application in study of dielectric electrical properties will be discussed. The pulser consists of a variable dc power source for high-voltage supply, two graded capacitors for energy storage, and the rotating spark gap switch. The key part is the multielectrode rotating spark gap switch (MER-SGS), which can ensure wider range modulation of pulse repetition rate, longer pulse width, shorter pulse rise time, remarkable electrical field distortion, and greatly favors recovery of the gap insulation strength, insulation design, the life of the switch, etc. The voltage of the output pulses switched by the MER-SGS is in the order of 3-50 kV with pulse rise time of less than 10 ns and pulse repetition rate of 1-3 kHz. An energy of 1.25-125 J per pulse and an average power of up to 10-50 kW are attainable. The highest pulse repetition rate is determined by the driver motor revolution and the electrode number of MER-SGS. Even higher voltage and energy can be switched by adjusting the gas pressure or employing N(2) as the insulation gas or enlarging the size of MER-SGS to guarantee enough insulation level.     

An PBЕ-73C vacuum spark gap with a control circuit based on an inductive energy storage

The design and operating principle of a small (50 mm in diameter and 100 mm in height) РВЕ-73C vacuum spark gap are described. It is shown that it can be efficiently switched using a control circuit with a low (∼900 V) supply voltage, which is based on an inductive energy storage and a diode opening switch that forms a high-voltage igniting pulse with a rise time of nanosecond duration. The РВЕ-73C switching process is investigated at different rise times of igniting voltage pulses and different igniting current amplitudes. The results of tests of the spark gap operating in regimes of switching current pulses with an amplitude of 12 kA and a rise time of 800 ns are presented.     

涡旋压缩机的实验研究及其工作性能分析

介绍了一种涡旋压缩机的实验研究,给出了设计工况下该型号压缩机的性能曲线,用十系数法得到了计算压缩机制冷量、输入功率和质量流量等性能参数的经验关系式。分析了吸气过热度对压缩机性能的影响,并对经验关系式进行了修正。修正后的经验关系式可以用来计算该型号压缩机实际运行时的性能参数。     

冰箱压缩机减振降噪的应用研究

对某型冰箱压缩机振动噪声进行了理论和实验分析 ,在此基础上 ,提出了一种新的冰箱压缩机减振降噪措施。基于高频隔振理论 ,重新设计了该型压缩机的压簧隔振系统。实验证实 :采用新型隔振系统的压缩机其平均噪声由 37.3d B(A)下降到 35 .0 d B(A) ,振动由 3.2 m/ s2 下降到 1.7m/ s2 ,取得了良好的减振降噪效果 ,这说明改进压缩机压簧隔振系统是一种有效的降低压缩机振动和噪声的方法。