Device for supplying a track-release or track-occupancy indication for a track section

摘要

A device for supplying a track-release or track-occupancy indication for a track section is disclosed, in which an alternating voltage input into a track circuit at a feed-in point (E) is tapped off at an extraction point (A), fed to an adder circuit (AD) and added there to a counter-voltage of the same frequency which is phase-shifted with respect to the fed-in alternating voltage by 180 DEG , the level of the counter-voltage being dimensioned such that, when the track is released it is lower but when the track is occupied it is higher than the voltage tapped off at the extraction point. In order to obtain a track-release or track-occupancy criterion, the phase shift of the output voltage (UM) of the adder circuit is compared with the phase shift of a comparison voltage (UV) derived from the fed-in voltage, in that pulsating direct voltages derived from the two voltages are fed both to an equivalence element (AE) and to an antivalence element (EO). Depending on the selected phase position of the comparison voltage, a track-release indication is issued at the output of the equivalence element and a track-occupancy indication is issued at the output of the antivalence element or a track-occupancy indication is issued at the output of the equivalence element and a track-release indication is issued at the output of the antivalence element. IMAGE