The MD-004 auto signal module provides automatic signalling for your model railway that simulates a real life block signalling system without any complex interlocking wiring.
The MD-004 module has a detection circuit, two timing circuits and an output circuit to provide the automatic operation on a single circuit board assembly. It uses a light dependent resistor to sense the passing of a train.
The MD-004 is designed to work with signals that have Light Emitting Diode (LED) lamps fitted. It also provides the voltage required for operation of the LEDs in the signal without the need for separate resistors.
The module requires an external regulated and filtered power supply of 12 to 14 V DC.
In operation the signal is normally set to green. When a train passes the signal a sensor fitted in the track between the rails detects the presence of the train and sends a signal to the MD-002 module. The signal is then set to red. After a predetermined time the signal automatically reverts to green in readiness for the next train to pass and start the cycle again.