- Published in issue 7/1996 on page 73
This circuit enables a model train to shuttle continuously between two tracks. When the train travels from left to right across the track in the lower part of the diagram, the lower rail D is connected to the positive supply line. After it has passed diode D(B), the train will stop. Since the locomotive short-circuits the diode when it passes the break in the rail, a short positive pulse is generated on rail section B.