Reed switches and Reed sensors in Lap counter in slot car racing tracks
Slot car racing (also called slot racing) is a competitive hobby of racing with powered miniature autos which are guided by grooves or slots in the track on which they run. The cars usually come with a pin which go into the slot. This pin is used to power the cars and also count the laps. Slot car racing tracks usually count the number of laps by having a small section of the track without power. Every time a car goes over this section, power consumption takes a dip and this is used as a lap counter. This also wears out the pins and the tracks. Instead of losing power to the tracks, reed sensors can be used on the track with all the cars having magnets. This ensures that the control circuits counts the reed switch pulses triggered by each car, as it completes a lap. This type of contact less sensing does not wear out any mechanical pins and can easily count millions of operations.