Welcome to practical physicsPracticle physics - practical activities designed for use in the classroom with 11 to 19 year olds
 

Track circuit relay and signals unit

Diode, IN4004 (Maplin QL76H) 
Miniature relay, 6 V/10 A (Maplin JM66W) 
Socket, 4 mm, (red) (JPR 705-205) 
Socket, 4 mm, (black) (JPR 705-206) 
Socket, 4 mm, (yellow) (2) (JPR 705-207) 
LES lamp holder, domed, red (Maplin RX78K) 
LES lamp holder, domed, green (Maplin RX77J) 
LES lamp, 6 V, (2) (Maplin WL74R) 
Plastic downpipe, square piece of, sawn in half (DIY store) 
Glue (Araldite Rapid or similar)
 
 
Construct unit as shown in the diagram.

Track circuit relay and signals unit

© University of York Science Education Group.