Hall Effect Sensor and gain circuit
Hall effect sensor with op-amp gain circuit to facilitate DC and DCC current detection
Schematic
Arduino
Because we have a DCC/DC mixed environment, we need a micro controller to monitor track voltage and no when voltage drops to zero, yet a DC trains is occupying the block. The controller will latch the "busy" signal for a set amount of time, or when voltage is above a threshold value to return to normal operation.