Often in ac circuit by air damping model time relay, it is to use the principle of air through orifices throttling to obtain delay action.
在交流电路中常采用空气阻尼型时间继电器，它是利用空气通过小孔节流的原理来获得延时动作的。
2
The analysis of step signal action on coupled resonant circuit is a difficult part in circuit analysis.
阶跃信号作用于耦合谐振电路的分析是电路分析中的难点。
3
This paper conducts a thorough research to the problem of short circuit override trip and inaccurate leakage protection action mainly existing in HV flameproof switchgear comprehensive protection.