Programmable instrumentation for high repetition rate experiments providing control in real time and acquisition of a train of pulses

Abstract

An automated, low-cost programmable instrumentation system which solves many of the problems associated with the data acquisition and control of high repetition rate experiments is described. The system can monitor and control experiments on a pulse-by-pulse basis while digitally storing consecutive pulses which occur in the train. The system compares well with manual test equipment and commercial transient diagnostic systems which cannot provide the high-speed control and data acquisition available here. The oscilloscope used to store the train of pulses can digitize at a maximum rate of 100 MHz, and has 32 kbytes of acquisition memory that can be subdivided into a sequence of as many as 250 separate segments. In order to reduce the system software reinitialization time to acquire each successive sequence within the total train, a novel IEEE-488 compatible microprocessor system is used in conjunction with a host personal computer. The microprocessor controls triggering of the experimental equipment based on digitally acquired waveform information. This information is also used to coordinate the reinitialization of the oscilloscope by the host computer. The system can acquire each and every pulse at repetition rates up to 40 Hz. Above this rate, the probability of acquiring a particular pulse in the train falls slightly below unity due to the finite time required to reinitialize the oscilloscope. The maximum synchronously controllable pulse repetition rate of the microprocessor is 20 000 Hz. Minimum performance specifications are provided which are significantly better than other approaches. The system is employed in high-voltage, dielectric breakdown experiments. For the example given, there are 62 segments in the acquired sequence, with a 100-MHz digitizing rate during the 5-μs acquisition time for each segment. The breakdown pulse in the train and as many as 61 pulses preceding it are obtained.

An experimental investigation of repetitive nanosecond-pulse breakdown in air

“…This time duration is referred to as the repetitive stressing time (RST). Generally, the number of applied pulses, with a microsecond or millisecond pulse width, can be counted using a digital counter or specially designed equipment with automated data acquisition and control functions [12,23]. In the experimental investigation, the number of applied pulses was calculated by measuring the time duration, t RST .…”

Measurement and control for a repetitive nanosecond-pulse breakdown experiment in polymer films

“…Generally, the pulse number can be counted by a counter connected with the trigger modulator. [6,14] In this case, the number of applied pulses can be calculated and it is about the product of TBD and PRF. For the case in Fig.…”

“…For example, for a repetitive µs-pulse breakdown, a programmable instrumentation system was needed to solve the problem of data acquisition. [14] It was found that the system could miss some pulses at a repetition rate above 40 Hz and the maximum applicable pulse repetition frequency (PRF) was 20 kHz. [14] Moreover, the instrumentation system needs some specially designed circuits which cannot be used in the measurement of repetitive nanosecond-pulse breakdown experiments directly.…”

“…[14] It was found that the system could miss some pulses at a repetition rate above 40 Hz and the maximum applicable pulse repetition frequency (PRF) was 20 kHz. [14] Moreover, the instrumentation system needs some specially designed circuits which cannot be used in the measurement of repetitive nanosecond-pulse breakdown experiments directly. In the experimental investigations of repetitive nanosecond-pulse breakdown in gases, [8−10] a high-power resistor was connected in series with the test chamber to avoid damage when breakdown occurred, and the power supply was turned off manually.…”

Low-Cost Measurement for a Secondary Mode S Radar Transmitter

“…So, this verification is performed without any dependence with the radar manufacturer. In short, for timing requirements, a global positioning system (GPS) disciplined oscillator (GPSDO) is used [13], and for sampling and storing the signal for proper automatic processing, a high-frequency sampling oscilloscope is used [14]. In addition, a computer is used to get the data from the oscilloscope for analysis and signal processing.…”