Heathcote Electronics MAS-4 3/4 Aspect Signal Sequencer Module
The MAS-SEQUENCER-4 operates a signal in the following way: The signal is normally at green. As a train passes the signal it will reach the MAS SEQUENCER-4 which detects the train by its built in infra detection, Detecting a train causes the signal to change to red. Once the train is clear of the MAS-SEQUENCER-4 s detector a timing sequence begins. This gives 3 equal timing intervals. The signal stays at red for the first interval, the signal changes to yellow for the second interval and for the third interval the signal changes to double yellow. At the end of which the signal changes to green. If another train arrives during this sequence then the signal will change to red and the sequence restart. The MAS-SEQUENCER4 can be used on its own to control a single signal. If more than one signal is on the same line the extra signals can be operated by IRDASC-4 units a connection from the MAS-SEQUENCER-4s "send" terminal to the following IRDASC-4s "receive" terminal tells the IRDASC-4 which aspect the MAS-SEQUENCER4 is at. For example if the MAS-SEQUENCER-4 is at yellow then the IRDASC-4 will set its signal to double yellow. Versions of the IRDASC-4 are also available for 2 and 3 aspect signals. For a full instruction sheet please go to our downloads tab.
Optional extended wiring is available from the drop down menu opposite. This extends the IR detectors by approx. 18 inches.