火箭发动机试验电磁阀电流隔离式测量电路
凌思睿,丁博深

(北京航天试验技术研究所,北京 100074)

电流测量; 电磁阀; 隔离; 反电势抑制; 温漂

Isolated solenoid valve current measurement circuit in rocket engine test
LING Sirui,DING Boshen

(Beijing Institute of Aerospace Testing Technology, Beijing 100074,China)

current measurement; solenoid valves; isolation; inverse voltage suppression; temperature drift

备注

火箭发动机地面试验中,需要对发动机和试验工艺系统的大量电磁阀进行控制和状态记录,要求电磁阀电流测量系统具有较高的静态精度和动态性能。为解决传统测量方法存在的问题,使用DC-DC模块和TPS717进行隔离供电,INA240放大10 mΩ采样电阻上的电压,AMC1311进行信号隔离,INA826调整增益并输出,实现了一种集成式的电流测量电路。误差分析表明电路总不可校正误差为0.144 9%。对实物电路板进行了校准测试,校准后精度优于0.025%,满量程-3 dB带宽为110 kHz,可广泛应用于火箭发动机试验等电流测量任务中。

In the ground test of rocket engine, a large number of solenoid valves in the engine and test process system were needed to be controlled and record state.The solenoid current measurement system was required to have high static accuracy and dynamic performance.Aiming at the problems in traditional application, an integrated current measurement circuit was realized.The DC-DC modules and TPS717 were used for isolated power supply.Voltage on the 10 mΩ shunt resistor was amplified by an INA240 and was isolated by an AMC1311.An INA826 was used for gain adjustment and output.In error analysis, test and calibration prove that the total uncorrectable error of the circuit is 0.144 9%.The calibrated accuracy is better than 0.025%.The -3 dB bandwidth of full output range is 110 kHz.This circuit can be widely used in the driving of various applications of current measurement such as in rocket engine tests.