基于自动亮度控制模型的门控型微光像增强器荧光屏亮度研究

为研究三代像增强器在强光环境下的有效保护措施,设计了一种基于荧光屏电流反馈来实现高照度环境下的自动亮度控制模型,并对该模型进行了仿真分析。制作了荧光屏亮度测试系统,对依托高照度自动亮度控制模型制作的门控电源像增强器进行了测试实验。通过测试像管响应时间和稳定时间,对像增强器门控电源在突发强光下产生理想控制效果的速度以及荧光屏亮度稳定的速度进行了分析。实验结果表明,荧光屏亮度变化趋势与仿真结果基本吻合,并且实验得到的荧光屏亮度曲线可以准确的反映门控电源的工作状态,为后续像增强器门控电源的性能测试提供了技术支持。     

Design of high-repetition frequency gating circuit for cathode of image intensifier北大核心CSCD

According to the requirements of high repetition frequency, fast edge speed and small pulse width for cathode gating signal by range-gated technology, a cathode high repetition frequency gating circuit using period and multi-stage acceleration was proposed. By combining the RC circuit and the high-speed gate circuit, the time bias circuit unit was cascaded to generate logic pulses with different time sequences, which could respectively control the intermediate stage drive MOSFET to generate three phased drive signals, and the output of the intermediate stage drive was used as input of the output-stage MOSFET to control the acceleration and retention of its on-off process. It was verified by software simulation and board-level test. The test results show that the proposed gating circuit can increase the edge time of output pulse from μs level to 2 ns, and can provide +50 V/−200 V cathode off/on voltage, so as to achieve a repetition frequency ranging from 0~350 kHZ, a duty ratio of 0~100%, a minimum pulse width of 3.7 ns, and a pulse output delay time jitter of about 0.1 ns. It has important guiding significance for improving the minimum pulse width performance of high-speed and high-voltage gating power, the highest working repetition frequency and reducing the power loss of the device. © 2022 Editorial office of Journal of Applied Optics. All rights reserved.