4.Main Content
apparatus
Track circuit relay and signals unit
To make the relay and signals unit you need
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.
© University of York Science Education Group
Updated 24 Nov 2004