Circuitron 800-5522 BD-2HD Current Sensing Block Occupancy Detector

Detects current drawn by a locomotive or lighted piece of rolling stock. Unpowered equipment can be detected by using metal wheelsets with resistors connected across the insulator.

Works in any scale and with most track power, systems including most forms of carrier control.
Will directly drive 2-color lamp (red and green) LED-type block signals.
250 ma. output (500 ma. for BD-2HD).
Circuit boards are designed for easy daisy-chain wiring of multiple blocks and will snap into a section of Printed Circuit Mounting Track
Requires 10-18V DC.
6 amp capacity.