Signal processing unit for a trolley pole switch controller

摘要

A signal processing unit for a controller of a trolley pole switch is disclosed. The trolley pole switch switches the path of travel that an energy collector takes through the switch at a junction of catenaries at which a turn catenary and a straight catenary diverge from the straight catenary. The signal processing unit includes an input stage, a detection stage, turn and straight signal demodulation stages and an output stage. The input stage conditions modulated signals, each of which indicating a request to switch the path of travel through the trolley pole switch to the desired catenary diverging therefrom. The detection stage generates a validation signal if the conditioned modulated signal falls within a predetermined band. If the turn demodulation stage receives a conditioned modulated turn signal from the input stage and the validation signal from the detection stage simultaneously, it generates a low logic signal. If the straight demodulation stage receives a conditioned modulated straight signal from the input stage and the validation signal from the detection stage simultaneously, it generates a low logic signal. If a low logic signal is received from the turn demodulation stage, the output stage energizes a turn relay thereby supplying power to a turn solenoid for switching the path of travel to the turn catenary. If a low logic signal is received from the straight demodulation stage, the output stage energizes a straight relay thereby supplying power to a straight solenoid for switching the path of travel to the straight catenary.