Marx Circuit Research Articles

Employment and fiscal policy in a Marxian model

AbstractThis article presents a simple formalization of Marx's circuit of capital framework, but with some modern additions: a public sector, an investment function that shifts over time in reaction to disequilibria, and a ‘wage curve’ linking income distribution to the size of the reserve army of labor. The dynamics can gravitate toward either a low‐employment trajectory in which public spending has expansionary long‐run effects, or a high‐employment trajectory characterized by a profit squeeze. The stability of the different trajectories depends on the investment function.

A novel trigger for pseudospark switch with high repetition rate, low jitter, and compact structure.

This paper presents the design and development of a trigger with a high repetition rate, low jitter, and compact structure for the pseudospark switch (PSS), which includes an improved Marx generator based on avalanche transistors and a corona-plasma trigger unit. The generator adopted a novel 3 × 12-stage Marx circuit based on avalanche transistors in which the failure rate of transistors in the first and second stages was significantly reduced by connecting the parallel capacitors compared to the previous similar generator. The reason for the improved performance was also discussed. The main parameters of output pulses were an amplitude of -7 kV, rise time of 6 ns, jitter of 0.2 ns, and repetition rate of 2 kHz. The corona-plasma trigger unit adopted BaTiO3 ceramics with high εr as the dielectric and was arranged in the hollow cathode of the PSS. The experiments of triggering a PSS prototype were conducted. The influence of anode voltage and pressure on the trigger delay and jitter was studied, and the minimum trigger jitter achieved <1 ns. This trigger worked for 107 shots at the repetition rate of 2 kHz continuously without obvious performance degradation and any failure of the generator. The main advantage of this trigger is the simultaneous combination of the high repetition rate, low jitter, long lifetime, and great simplicity in a compact structure.

Development of a hybrid mode linear transformer driver stage

At present, the mainstream technologies of primary power sources of large pulse power devices adopt Marx or linear transformer driver (LTD) designs. Based on the analysis of the characteristics of these two types of circuit topologies, the concept of a hybrid mode LTD stage based on Marx branches is proposed. The analysis shows that the hybrid mode LTD stage can realize the following goals: (a) to reduce the energy and power handled by the basic components (switch and capacitor) to lengthen their lifetime; (b) to reduce the requirements of the multipath synchronous trigger system; and (c) to improve the maintainability of the LTD stage by using independent Marx generators instead of ``traditional LTD bricks.'' To verify the technique, a hybrid mode LTD stage consisting of 50 branches (four-stage compact Marx generators) was designed, manufactured and tested. The stage has a radius of about 3.3 m and a height of 0.6 m. The single Marx circuit's load current is about 21 kA, with a rise time of $\ensuremath{\sim}90\text{ }\text{ }\mathrm{ns}$ (10%--90%), under the conditions of capacitors charged to $\ifmmode\pm\else\textpm\fi{}40\text{ }\text{ }\mathrm{kV}$ and a $6.9\text{ }\text{ }\mathrm{\ensuremath{\Omega}}$ matched load. The whole stage's load current is $\ensuremath{\sim}1\text{ }\text{ }\mathrm{MA}$, with a rise time of $\ensuremath{\sim}112\text{ }\text{ }\mathrm{ns}$ (10%--90%), when the capacitors are charged to $\ifmmode\pm\else\textpm\fi{}45\text{ }\text{ }\mathrm{kV}$ and the matched load is $0.14\text{ }\text{ }\mathrm{\ensuremath{\Omega}}$.

Modified High-Power Nanosecond Marx Generator Prevents Destructive Current Filamentation

A traditional Marx circuit (TMC) based on avalanche transistors with a shortened emitter and a base was investigated numerically by using a two-dimensional (2-D) physics-based approach and experimentally, and compared with a special Marx circuit (SMC) suggested here, in which an intrinsic base triggering of all the stages protects the transistors, especially the second one, from thermal destruction due to current filamentation. This is because the entire emitter–base perimeter in the SMC participates in switching, whereas in a TMC the switching is initiated across the entire area of the emitter but then changes to current filamentation due to certain 3-D transient effects reported earlier. Very significant difference in local transient overheating in the transistors operating in TMC and SMC determines the difference in reliability of those two pulse generators. The results suggest a new circuit design for improving reliability and explain the difference in the operating mode of different transistors in the chain which makes the second transistor most prone to destructive thermal filamentation. This new understanding points additionally to ways of optimizing the design of the transistors to be used in a Marx circuit.

A hybrid pulse combining topology utilizing the combination of modularized avalanche transistor Marx circuits, direct pulse adding, and transmission line transformer.

Numerous applications driven by pulsed voltage require pulses to be with high amplitude, high repetitive frequency, and narrow width, which could be satisfied by utilizing avalanche transistors. The output improvement is severely limited by power capacities of transistors. Pulse combining is an effective approach to increase the output amplitude while still adopting conventional pulse generating modules. However, there are drawbacks in traditional topologies including the saturation tendency of combining efficiency and waveform oscillation. In this paper, a hybrid pulse combining topology was adopted utilizing the combination of modularized avalanche transistor Marx circuits, direct pulse adding, and transmission line transformer. The factors affecting the combining efficiency were determined including the output time synchronization of Marx circuits, and the quantity and position of magnetic cores. The numbers of the parallel modules and the stages were determined by the output characteristics of each combining method. Experimental results illustrated the ability of generating pulses with 2-14 kV amplitude, 7-11 ns width, and a maximum 10 kHz repetitive rate on a matched 50-300 Ω resistive load. The hybrid topology would be a convinced pulse combining method for similar nanosecond pulse generators based on the solid-state switches.

Membrane Permeabilization of Pathogenic Yeast in Alternating Sub-microsecond Electromagnetic Fields in Combination with Conventional Electroporation.

Recently, a novel contactless treatment method based on high-power pulsed electromagnetic fields (PEMF) was proposed, which results in cell membrane permeabilization effects similar to electroporation. In this work, a new PEMF generator based on multi-stage Marx circuit topology, which is capable of delivering 3.3T, 0.19kV/cm sub-microsecond pulses was used to permeabilize pathogenic yeast Candida albicans separately and in combination with conventional square wave electroporation (8-17kV/cm, 100μs). Bursts of 10, 25, and 50 PEMF pulses were used. The yeast permeabilization rate was evaluated using flow cytometric analysis and propidium iodide (PI) assay. A statistically significant (P < 0.05) combinatorial effect of electroporation and PEMF treatment was detected. Also the PEMF treatment (3.3T, 50 pulses) resulted in up to 21% loss of yeast viability, and a dose-dependent additive effect with pulsed electric field was observed. As expected, increase of the dB/dt and subsequently the induced electric field amplitude resulted in a detectable effect solely by PEMF, which was not achievable before for yeasts in vitro.

Compact solid-state Marx-bank sub-nanosecond pulse generator based on gradient transmission line theory

For non-invasive treatments in the biomedical field, sub-nanosecond pulse electric field matching ultra-wideband antennas have aroused great interest for their excellent directivity and targeted treatment. Sub-nanosecond pulse generators have proved difficult to control in pulsed power technologies despite many studies of pulse generators based on avalanche transistor theory and the Marx circuit. However, no solution exists to the problems of non-ideal waveform of the output sub-nanosecond pulse and the relatively low effectiveness of the Marx circuit. To resolve these problems, the paper describes a sub-nanosecond pulse generator simulation model based on gradient transmission line theory in PSPICE simulation software and the development of a compact solid-state sub-nanosecond pulse generator (18 cm×18 cm×4 cm). From experimental tests, trigger signals of 5-V amplitude, 5-ns rise and fall times (pulse-width 10 ns-50 ns) were generated by Field-Programmable Gate Array (FPGA). A pulse with 1600-V voltage amplitude, 300-ps full width at half maximum, 150-ps rise time, and 10-kHz high-stability repetition rate was generated in an attenuator load with high-bandwidth (8 GHz, 50 Ω). The effectiveness (Output pulse voltage amplitude / Charge voltage × Stages) of this Marx circuit reached to 41.7%, improving considerably on previous efforts.

Solid-State Nanosecond-Pulse Plasma Jet Apparatus Based on Marx Structure With Crowbar Switches

Atmospheric-pressure plasma jets (APPJs) are widely used in biomedical treatment, surface modification, and sterilization, among others because of their advantages of simple structure, strong chemical activities, nonthermal effects, and convenient handling. In this paper, a nanosecond-pulse power generator based on Marx circuit is proposed. The apparatus consists of a nanosecond-pulse generator with crowbar switch and a needle-ring structure electrode. The nanosecond-pulse generator is modularly designed with ten stages; MOSFETs are used as the main switch and crowbar switch on each stage. A field-programmable gate array is used to generate two-channel trigger pulse signals to control the turn-on or turn-off of switches. The generator can produce repetitive pulses with output voltages of up to 8 kV, pulsewidth of 100–1000 ns, rise time of less than 30 ns, and pulse repetition frequencies of 1 Hz to 1 kHz. The designed nanosecond-pulse generator and the needle-ring structure electrode are used to produce argon plasma jets into open air, and the experiments show that the nanosecond-pulse generator can sustain stable APPJs. This paper lays a foundation for the further exploration of the biomedical effects of APPJs.

Development and Simulation of a Compact Picosecond Pulse Generator Based on Avalanche Transistorized Marx Circuit and Microstrip Transmission Theory

The new biological effect of picosecond pulsed electric fields (psPEFs) has elicited the interest of researchers. A pulse generator based on an avalanche transistorized Marx circuit has been proposed. However, the problem of reflection in the transmission of the generated picosecond pulse based on this circuit has not received much attention and remains unresolved. In this paper, a compact picosecond pulse generator based on microstrip transmission theory was developed. A partial matching model based on microstrip transmission line theory was also proposed to eliminate reflection, and a series inductor was utilized to optimize pulse waveform. Through simulation studies and preliminary experimental tests, a pulse optimized with 1015 V amplitude, 620-ps width, and 10-kHz high stability repetition rate was generated. This pulse generator can be used with microelectrodes in cell experiments to explore the biological effect mechanism of psPEF.

Theoretical Analysis and Experimental Study on an Avalanche Transistor-Based Marx Generator

High-voltage, nanosecond, high-repetitive-frequency, and portable pulse generators are always required in many fields. Avalanche transistor-based Marx circuits have been widely studied to generate pulses satisfying the above requirements. However, the basic topology of an avalanche transistor-based circuit, configuration of circuit parameters, and optimal working performance (including output impedance matching) were still scarcely discussed. In this paper, the detailed process of analyzing and designing a compact Marx generator using avalanche transistors was described. Based on the conventional principles of avalanche transistors and Marx circuit, a list of useful and interesting conclusions was discovered by experiment. An example with specific parameter requirements was utilized for the clearness of illustration. The $12~{\rm cm}\times 4$ cm Marx circuit could finally generate pulses with a 2.5-kV amplitude, 6.0-ns width, 10-kHz repetitive frequency, lower than a 100-ps jitter and $\sim 125$ -kW maximum peak output power on a matched 50- $\Omega $ resistive load. The pulse amplitude could be adjusted from 1.5 to 2.5 kV and the pulse width could also be broadened. This paper may help to provide a reference to similar methods of producing high-voltage, nanosecond, and high-repetitive-frequency pulses.

Development of a stereo-symmetrical nanosecond pulsed power generator composed of modularized avalanche transistor Marx circuits.

Avalanche transistors have been widely studied and used in nanosecond high voltage pulse generations. However, output power improvement is always limited by the low thermal capacities of avalanche transistors, especially under high repetitive working frequency. Parallel stacked transistors can effectively improve the output current but the controlling of trigger and output synchronism has always been a hard and complex work. In this paper, a novel stereo-symmetrical nanosecond pulsed power generator with high reliability was developed. By analyzing and testing the special performances of the combined Marx circuits, numbers of meaningful conclusions on the pulse amplitude, pulse back edge, and output impedance were drawn. The combining synchronism of the generator was confirmed excellent and lower conducting current through the transistors was realized. Experimental results showed that, on a 50 Ω resistive load, pulses with 1.5-5.2 kV amplitude and 5.3-14.0 ns width could be flexibly generated by adjusting the number of combined modules, the supply voltage, and the module type.

Performance Analysis of a Short-Pulse Marx Generator for High-Power Relativistic Applications With a Solution Load

Many approaches exist for energy storage and delivery to the load, including high-power relativistic applications. One of the best solutions for the driver of high-power relativistic applications is the Marx generator. This paper describes the design, fabrication, and experimental validation of a Marx generator consisting of capacitors, spark-gap switches, and resistors. It is designed as an eight-stage Marx circuit to reach an output voltage level as low as −500 kV, and it is directly connected to the Blumlein pulse-forming line (PFL) to achieve more than 100 ns of the full-width at half-maximum. Experiments are performed with a solution load in a manner similar to having a coaxial structure in a high vacuum with a pressure of below $0.5\, \times \, 10^{-5}$ torr, to prevent breakdown and measure the amplitude of the negative high-voltage pulse waveform. The solution load is designed to capture the short-pulse output of the PFL with a rise time of less than 25 ns and a voltage level of approximately −500 kV. The experimental results show that the output pulse can be used as a source to generate an intense relativistic electron beam at the gun for high-power relativistic applications.

High voltage high repetition rate pulse using Marx topology

The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

A Subnanosecond Jitter Trigger Generator Utilizing Trigatron Switch and Avalanche Transistor Circuit

High-performance trigger generators with high amplitude, fast rise time, low jitter are essential for large-scaled pulsed-power systems. Most of the trigger generators are also tiny multistage pulsed-power systems with complicated structures. In this paper, a high-performance trigger generator was proposed by combining the advantages of low-jitter semiconductor switch and high-power gas switch. An avalanche transistor Marx circuit was developed. It was used to trigger a two-stage Marx generator based on trigatron switch. The output characteristics of the Marx circuit based on avalanche transistors and the two-stage Marx generator were studied. The experimental results show that a subnanosecond jitter, nanosecond rise time, high-voltage trigger generator can be achieved by triggering trigatron switch with an avalanche transistor circuit.

Design of all-solid-state modularized Marx circuit and synchronous combining of pulses

Design of all-solid-state modularized Marx circuit and synchronous combining of pulses

Design of Marx generators as a structured eigenvalue assignment

We consider the design problem for a Marx generator electrical network, a pulsed power generator. We show that the components design can be conveniently cast as a structured real eigenvalue assignment with significantly lower dimension than the state size of the Marx circuit. Then we present two possible approaches to determine its solutions. A first symbolic approach consists in the use of Gröbner basis representations, which allows us to compute all the (finitely many) solutions. A second approach is based on convexification of a nonconvex optimization problem with polynomial constraints. We also comment on the conjecture that for any number of stages the problem has finitely many solutions, which is a necessary assumption for the proposed methods to converge. We regard the proof of this conjecture as an interesting challenge of general interest in the real algebraic geometry field.

Design of Miniature Dual Exponential Pulse Source Using EMC Experiment

Based on avalanche effect of avalanche transistor, Marx circuit configuration is adopted, trigger circuit and PCB layout are described in detail. The all-solid-state pulse source is designed with 10-stages Marx circuit. The test results demonstrate that its output impedance is 50Ω, the pulse width is 10ns approximately, pulse voltage is about 1.5kV,the rise time of the positive pulse is less than 2ns, the fall time of negative pulse is about 3ns, the operating frequency is 10kHz, coefficient of variation for voltage peak, fall time and pulse width is less than 5%, which is suitalbe as interference source for the EMC experiment.

The Simulation and Realization Methods of Partial Discharge Signal in Gas Insulated Substation

On the basis of the analysis of simulating the partial discharge (PD) signals in Gas Insulated Substation (GIS), this paper focuses on discussing the common simulation and realization methods of simulating the partial discharge signals in mechanical and electrical equipments. The characteristics of PD signals and the typical insulation defects of GIS are reviewed. Different simulation methods to simulate the PD signals are considered. Two implementation schemes of simulating the discharge pulse are analyzed and compared with each other. Through the analysis, we find out that the electronic technology will be the most hopeful way to achieve the desired goals, which are to simulate those PD signals. This paper provides a simulation scheme of simulating PD signals, which can be described as multi-stage paralleling of MARX circuit and can provide a reliable reference for engineering practice.

FPGA-Controlled All-Solid-State Nanosecond Pulse Generator for Biological Applications

In vivo studies of tumor-cell apoptosis induced by nanosecond pulsed electric field require high-voltage nanosecond pulses delivered to the biological tissues. In this paper, a newly developed all-solid-state nanosecond pulse generator based on the Marx generator concept is proposed for this application. The generator comprises four parts: a dc charging power, a solid-state Marx circuit using metal-oxide-semiconductor field-effect transistors, a control circuit using a field-programmable gate array, and the load. This generator has the capability of producing repetitive pulses with a voltage up to 8 kV, pulsewidth of 200-1000 ns, rise time of 35 ns, and repetition rate of 1-1000 Hz with various resistive loads and 1-kV dc input voltage. The all-solid-state design makes the generator compact and reliable. Initial experiments were carried out to verify the performances of the proposed generator.

Understanding the Fundamentals of Capital, the Crisis and the Alternatives: Marx's Legacy beyond Revolutionary Marxism

Research Highlights and Abstract Critically engages with analyses of fundamental principles associated with capitalist crisis as differently presented in the theories of Karl Marx and John Maynard Keynes. Critiques the narrow labour-focused account of Marx's circuit theory of capital found in so-called ‘Open Marxism’. Highlights the importance of Keynes's treatment of money as an independent variable to the further development of circuit and crisis theories. More generally opens up Marxian circuit and crisis theory to broader heterodox perspectives in political economy, especially critical Keynesian and Schumpeterian perspectives. Seeks to apply a critical evaluation of crisis and circuit theories to the contemporary global financial crisis, not least by critiquing Peter Burnham's ‘depoliticisation’ account of the crisis of macro-economic management. Argues instead that the politicized nature of money remains deeply embedded both nationally and internationally. This article critically engages with Peter Burnham's recent call for a ‘return to fundamentals’ and specifically to Marx as a basis for understanding the global financial crisis (GFC) and its still unfolding aftermath. The article criticises Burnham's ‘Open Marxist’ account of Marx's capital theory and his reading of the crisis in terms of ‘depoliticisation’ and the reassertion of the law of value over the state. The article focuses on Schumpeterian and Keynesian theories of crisis and crisis management as derived from fundamentals. It argues that Keynes, in particular, offered a theory of crisis that, while consistent with Marx's circuit theory of capital, was also distinct in its focus on money. In short, Keynes politicised money and its management. How the current global crisis is ultimately resolved depends crucially on understanding both the limits and possibilities for the repoliticisation of money in the post-neoliberal era.