When the optimal inductance and resistance of the piezoelectric shunting circuit are obtained, the peak of the first order vertical bending vibration peak can be reduced obviously.

Aim at the problem of the pressure small, easily test error of adoption shunting line test residual press, develop a new track circuit shunt-residual press fix tester.

Based on the analysis of short circuit process, the principle to select relevant parameters when applying short circuit shunting protection is introduced.