If you race with a club or frequent a commercial slot car track, chances are you've heard racers shouting "Track!" whenever a car de-slots or some other problem arises which potentially creates a hazard. Most club and commercial tracks run some sort of race management software to keep track of lap counts and lap times as well as manage lane rotations during actual races. Many of these race management software products include a feature to control track power using one or more relays and track call buttons. At a minimum, there is usually a least one track call button at the "race director's" station. When someone yells "Track!", the race director (at their discretion...) will push the track call button. The track call button is nothing more than a momentary switch which signals the race management system to temporarily suspend power (via one or more relays) to the track. Most race management software will also suspend lap timing and lap counting. When the problem causing the track call has been corrected, the race director will press the track call button again. This signals the race management software to restore track power and resume lap counting and timing. Some layouts take this arrangement a step further and have multiple track call buttons - for example, in addition to the race director's station, track call buttons may be present at each of the driver's stations.
Wiring track call buttons is not difficult; however, a little planning can make your track call setup very flexible and easy to reconfigure should the need arise. The attached wiring diagrams show a modular approach to wiring one or more track call buttons. The modularity associated with this approach is achieved by using terminal blocks in lieu of simply hard-wiring all connections in a point-to-point fashion. Some of the advantages of this approach include:
Flexibility to "move" the track call button(s) should you change or expand your track layout.
Ease of incorporating additional track call buttons - now or in the future
Ability to "group" track call buttons and enable/disable groups as required. For example, you might have a track call button for the race director's station and track call buttons at each driver's station. During informal practice and racing (when a "race director" may not be present) you may want the track call buttons at the driver's stations to be enabled. During a formal race when a race director is present, you may want just the race director to manage track calls. By segregating/grouping the track call buttons at the driver's stations, a simple on-off switch can be used to disable all of them as a group.
Ease of troubleshooting track call wiring
The wiring diagrams are based on Trakmate for Windows (a popular race management system); however, the same general wiring approach can be used with other race management systems which support track calls. High quality track call buttons, terminal blocks, and relays are available in the Online Store.