微震仪放大器级间耦合电路对初动的影响

EFFECT OF COUPLED CIRCUITS BETWEEN AMPLIFIER STAGES ON SEISMIC ONSET

本文通过对RC耦合电路的初动特牲进行理论推导,并对67-1和DDF-2放大器耦合电路进行验算,得出结果:DD-1地震仪初动特性不及熏烟记录地震仪,主要是由放大器级间耦合电路时间常数偏小所致。实验表明,增大DDF-2放大器的耦合电容,可以明显改善初动特性,但RC时间常数过大,因过渡过程的作用,波形失真也相应增大。

We derived theoretically the onset featurw of RC coupled circuits, calculatedand checked the coupled circuits of the 67-1 amplifier and DDF-2 amplifier.wefound that the onset feature of DD-1 seismograph is inferior to that of recordingon smoked paper because the time constant of the coupled circuits between ampli-fiers is somewhat too small. We also found that if we increased the couplingcapacity of the DDF-2 amplifier, the onset feature clearly improved, while thewaveform distortion would increase correspondingly.