在地震观测中广泛使用的 DD-1、DK-1地震记录仪,常常由于推动线路及同步马达的故障而中断记录,特别在夜间,一旦记录滚筒停转,就会给记录资料造成损失。为解决这一问题,笔者试做了一个停机报警装置。本装置具有原理简单、安装容易、使用方便、性能可靠等优点。它可以应用在滚筒记录的(如地震仪记录滚筒、地磁和地倾斜滚筒等)各类仪器上。1.电路结构和工作原理(1)电路结构。地震仪停机报警器的基本电路结构见图1。T_1、T_2、T_3、D、R_1、R_2、R_3、R_4、R_5、R_6及 C_1、C_2构成一个延时电路,R_7、R_8、R_9、T_4、T_5及 C_3构成一个实用电子门 DD-1 and DK-1 seismographs, which are widely used in seismic observations, often interrupt recording due to faulty circuits and synchronous motors, especially at night when recording drums stall. To solve this problem, I tried to do a shutdown alarm device. The device has the advantages of simple principle, easy installation, convenient use and reliable performance. It can be applied to all kinds of instruments recorded on rollers (such as seismograph record rollers, geomagnetism and tilt rollers, etc.). 1. Circuit structure and working principle (1) circuit structure. Seismograph shutdown alarm basic circuit structure shown in Figure 1. T_1, T_2, T_3, D, R_1, R_2, R_3, R_4, R_5, R_6 and C_1, C_2 constitute a delay circuit, and R_7, R_8, R_9, T_4, T_5 and C_3 form a practical electronic gate