Rise time

About: Rise time is a research topic. Over the lifetime, 4748 publications have been published within this topic receiving 47512 citations.

Verification of Rogowski current transducer's ability to measure fast switching transients

Abstract: Rogowski current transducers combine a high bandwidth, an easy to use thin flexible coil, and low insertion impedance making them an ideal device for measuring pulsed currents in power electronic applications. Practical verification of a Rogowski transducer's ability to measure current transients due to the fastest MOSFET and IGBT switching requires a calibrated test facility capable of generating a pulse with a rise time of the order of a few 10's ns. A flexible 8-module system has been built which gives a 2000A peak current with a rise time of 40ns. The modular approach enables verification for a range of transducer coil sizes and ratings.

A low-cost millimeter-wave glow-discharge detector

Abstract: A low-cost millimeter-wave glow-discharge detector characterized by a responsibility of 0.177 V/W, a rise time of 2.5 µs, and a noise equivalent power (NEP) of ∼10-13W/Hz when used in a synchronous detection mode is described. Low NEP is accomplished through a novel biasing arrangement of a commercially available three-electrode glow-discharge lamp originally intended for triggering applications. This biasing arrangement leads to rms noise voltage suppression of nearly 20 dB. This, together with other known properties, makes this detector particularly suited for use in closed-range microwave hologarphic arrays.

The resistive phase of a high-voltage water spark

Abstract: The resistive phase of self‐breaking water‐dielectric spark gaps in a high‐current relativistic electron‐beam accelerator is investigated experimentally. For gaps that withstand voltages V?1.8 MV and mean electric fields between 2×107 and 5×107 V/m, both the current rise time and the energy dissipated in the discharge are adequately described by the semiempirical relations of Martin. In contrast to the results reported in lower‐energy experiments, no evidence was found of a slowly varying resistive phase with a gap resistance comparable to the circuit impedance after t=2.5τr. Approximately 8±3% of the energy dissipated in the gap is coupled into a shock wave generated by the discharge. Light emission from the arc channels indicated that the light was strongly filtered by the highly excited water surrounding the channel, and the light emission cannot be analyzed to determine the plasma properties of the arc channel unambiguously.

Very Fast Rise-Time Short-Pulse High-Voltage Generator

Abstract: This paper relates to the development of an ultrafast compact system readily applicable to the field of ultrawideband microwave applications such as transient radar or laser drivers. The design, production, and experimental results of a short-pulse generation system are presented in this paper. The coaxial generator technology based on the principle of a line discharge by means of a high-pressure gas switch in a simple transmission line arrangement is described. In the first stage of the process, the coaxial generator was charged by a high-voltage direct current source. Interesting results were obtained, but due to the jitter of the discharge formative time, the reproducibility of the output pulses was not sufficient. To improve the performance, a pulsed source was developed in order to apply an overvoltage to the gap switch and thus reduce the jitter of the discharge formative time. The characteristics of the pulsed source are defined. A thyristor Marx generator and a pulse transformer using magnetic properties of ferrite cores were combined in order to produce this pulsed source. The main performances of this source are a pulse amplitude of 60 kV, a rise time of 250 ns, and a maximum frequency of 900 Hz from a 1-kV dc supply. Finally, the complete generation system is able to generate pulses with 25-kV amplitude and 70-ps rise time through a 50-Omega impedance from the single shot mode up to 900 Hz. The output pulses reproducibility obtained is better than plusmn5%

Solid-State LTD Module Using Power MOSFETs

Abstract: It is proposed that linear transformer driver (LTD) concept can be applied to compact repetitive pulsed-power generation. For experimental demonstration, a table-top LTD module has been constructed by using power metal-oxide-semiconductor field-effect transistors (MOSFETs) and film capacitors. It consists of 24 basic circuits and a magnetic core, contained in a cavity case having a diameter of 32 cm and a height of 1.1 cm. All MOSFETs can be turned on and off synchronously, controlled by a single optic fiber. This LTD module has been tested with operation voltage of 900 V for single shot and 700 V for repetitive operation at 500 Hz. Near-rectangle waveforms were obtained on a resistive load of 3.2n , with pulsewidth of 200 ns, rise time of 20 ns, and fall time of 40 ns. The overall system efficiency was obtained to be 76%.