The supervision and inspection of 25Hz phase detecting track circuit broken rail or track lead have been affecting the operation safety of railway for a quite long period.

Through summarizing and classifying the faults of 25Hz phase detecting track circuit,fault processing methods were introduced systematically.

25Hz Series Track Circuit Receiver Design Based on DSP;

A new_style electronic receiver of 25Hz series track circuit is introduced, which replaces the old 25Hz track relay.

Software design of track circuit frequency shift signal detection system;

The fault analysis,judgment and maintain of 25Hz microelectronic phase-sensitive track circuit;

Software design on Automatic Test System of ZPW-2000A track circuit;

Using digital logic circuit to control the parallel network of analog switches and resistances ,the voltage to ground is automatically regulated to reach equilibrium tested by phase sensitive circuit,and so the measurer takes an automatic measurement of ground resistance.