介绍了一种用于主动减小NQR探头恢复时间的Q值变换电路,它利用MOE-FET控制变Q电路与探头电路的耦合,并通过变压器增加与电感线圈串联的阻抗值以达到改变Q值的目的.此电路不会产生新的振铃也不会对接收NQR的分辨率造成损失.实验结果表明,电路能有效缩短探头的恢复时间,同时还可以提高信噪比. A Q-value conversion circuit is proposed for actively reducing the recovery time of an NQR probe. The MOE-FET is used to control the coupling between the Q-switching circuit and the probe circuit. The impedance of the inductor in series with the transformer is increased to change the Q value This circuit will not generate new ringing nor will it cause loss of resolution of the receiving NQR.The experimental results show that the circuit can shorten the recovery time of the probe and improve the signal to noise ratio.