根据线性微分方程理论重新表述了一种普适的电路起振条件判据，据此推导出三个典型电路起振时的元件参数的取值范围，通过仿真试验加以验证。-According to the theory of linear differential equations re-expression of a universal criterion for the circuit start-up conditions, which are derived three typical circuit components at the time of start-up parameters range, through the simulation test to verify.