6 results about "Pulse rise time" patented technology

The invention discloses a multi-objective optimization design method for a high-voltage nanosecond pulse adder, and aims to solve the problem that the prior art depends on experience trial and error and is difficult to consider multiple objectives such as fast leading edge, high efficiency, portability and reliability. The method comprises the following steps: firstly, building a simulation and experiment platform, and acquiring output waveform data for changing topological parameters; constructing a physical model of the influence rule of the parasitic parameters on the pulse rising edge time and the voltage gain, and establishing a power supply efficiency prediction model based on a deep neural network; taking the minimization of the pulse rising edge time and the maximization of the voltage gain and the energy efficiency as targets, constructing a particle swarm optimization multi-target optimization model in combination with the model, and obtaining a Pareto optimal solution set under the constraints of portability and parasitic parameters; and finally, carrying out experimental verification iteration to obtain an optimal scheme. According to the invention, the design period is obviously shortened, the multi-target conflict is effectively balanced, the rising edge time is shortened, the energy efficiency is improved, the voltage gain is improved, the portability is enhanced through the modular design, and the wearable application is compatible.

This invention discloses a high-voltage nanosecond pulse shaping device and method based on magnetic devices. The device includes: a first magnetic transmission line and a second magnetic transmission line, with their input ends connected in parallel and connected to an initial pulse source; the output end of the first magnetic transmission line is connected to a load terminal; the output end of the second magnetic transmission line is short-circuited to ground; the first magnetic transmission line includes a first magnetic ring arranged along the axial direction and an outer magnetic field coil; the second magnetic transmission line includes a second magnetic ring arranged along the axial direction. Based on the current-dependent nonlinear permeability effect of the magnetic ring, this device simultaneously achieves pulse rise time compression, fall time truncation, pulse width shortening, and suppression of pre-pulse and tail oscillations through the rising sharpening effect of the first magnetic transmission line and the falling truncation effect of the second magnetic transmission line. This overcomes the limitation of single nonlinear transmission line or magnetic switching technology, which can only optimize single pulse parameters, and can obtain high-quality pulse waveforms at the load terminal.

A pulsed laser system includes a laser that delivers a light pulse to an optical shutter configured to transmit, of the pulse: (a) a first transmitted portion having a rise time of less than 20 ns and a first portion peak power, then (b) a second transmitted portion having an initial power less than the first portion peak power, and then (c) a third transmitted portion having an energy of at least 100 nJ and a duration of less than or equal to 200 ns. A low voltage driver (to control transmission of the first transmitted portion) can be connected to an EOM in the optical shutter in parallel with a high voltage driver (to control transmission of the third transmitted portion), with electrical isolators positioned the outputs of the respective voltage drivers to protect the low voltage driver.

The application provides a magnetic blow-by treatment method, device and welding system. The method comprises: after the start of a first pulse period, performing pulse welding with first welding parameters; obtaining an actual pulse base value voltage; determining whether magnetic blow-by occurs based on the actual pulse base value voltage and a first preset pulse base value reference voltage; if magnetic blow-by occurs, increasing the pulse rise time and the pulse fall time in the next pulse period of the first pulse period, and reducing the pulse peak current, so as to perform pulse welding based on the adjusted pulse rise time, pulse fall time and pulse peak current in the next pulse period, thereby improving the anti-interference ability of the pulse arc to magnetic blow-by, ensuring the one-pulse-one-drop droplet transfer state, enabling the arc to maintain good stability during welding, and thereby reducing or eliminating the influence of magnetic blow-by on the pulse welding efficiency and the pulse welding effect, so that the pulse welding efficiency is higher and the pulse welding effect is better.

This invention discloses an online dose monitoring and alarm system and method for boron neutron capture therapy, belonging to the field of radiation dose monitoring technology. It includes at least one set of integrated wireless monitoring probes and a central monitoring platform. The system highly integrates a radiation detection module, a photoelectric conversion module, a high-speed analog-to-digital / digital-to-analog conversion module, an FPGA module, a wireless communication module, and a built-in lithium battery. The FPGA executes a shape discrimination algorithm based on the difference between pulse rise time and / or decay time at the probe end using hardware logic to distinguish neutron / gamma events and calculate the count rate and dose rate in real time. When the monitored value exceeds a preset safety threshold, the high-speed digital-to-analog conversion module drives an LED indicator and / or a buzzer to issue a local audible and visual alarm. Compared with existing technologies, this invention achieves synchronous real-time monitoring of neutron flux and gamma dose, improves alarm response speed, facilitates flexible deployment near the treatment head or patient irradiation field in space-constrained locations, and enhances the safety and accuracy of treatment.

The invention provides a complex pulse signal pulse parameter metering calibration device, which comprises an AD sampling device for acquiring a measured signal and performing AD sampling on the measured signal to generate a sampling signal; the calibration module is used for carrying out metering calibration on the sampling signals at a digital end so as to measure pulse parameters, and the items of metering calibration comprise filtering, feature recognition, pulse envelope monitoring, automatic time window taking and pulse parameter measurement; the traceability module is used for tracing the metrological characteristics of the calibration module at the digital end according to the measurement information of the calibration module; wherein the source is traced to a time frequency parameter based on frequency measurement information, the source is traced to a time interval based on pulse width and pulse delay measurement information, the source is traced to a standard pulse rise time based on pulse rise / fall time measurement information, and the source is traced to a standard square wave amplitude based on pulse top fluctuation measurement information. According to the invention, the pulse parameter metering of the complex coded modulation pulse is completed through a digital means, and the metering efficiency and accuracy are improved.