A very short history of the controller. In the early days of slot racing the first sets were equipped with simple on-off switches (the button style controllers) but for the tight corners a more sophisticated controller was needed.
Too hot to handle
Hobbyists tried to make a controller with a volume knob of a radio. The English firm Model Road Racing Cars offered the first controller that was operated by the thumb by pushing down on a plunger.
The first devices were very small and became very hot. Jim Russel of the American Company Russkit developed the first pistol-grip controller. With this type of controller the enthusiast did not feel the heat anymore, because the resistor is not positioned in the grip of the controller. Other companies copied the design. The companies promoted their products in the slot track magazines. In the add of Testor it was written that the modern ari-flo design of the T3X controller kept the giant resistor out of the hand and keeps the controller cool and comfortable. The slogan of Testor: When you’re racing a lot, the controller gets hot…not this one!
The trigger of a pistol-grip controller is moved by the index finger. The trigger wipes across the ceramic wire-bound resistor inside. The trigger type controller is standard offered by almost all manufacturers in current race sets. You have better reflex action with the index finger than the thumb, according to the designer of the pistol-grip controller. But nature has its own rules. It is interesting to see that children who get a pistol-grip controller in the hand they automatically change the grip and operate the trigger with the thumb.
Dynamic braking system
Dynamic braking system was the next development. A dynamic brake is an open circuit across the motor brushes that forces the motor to act as a generator (the motor tries to stop turning) as it slows down. A third wire is needed to get the motor in that full “off” position. In the early days the track was not wired for controllers with a dynamic braking system. Nowadays all track sets feature this system.
The electronic controller is widely used nowadays. Some manufacturers offer this type of controller, but many home racers prefer the mechanical controller. The inexpensive Parma controller, originally designed by Russkit, is very popular around the world.
The latest development in controller technology is Digital racing. Each car receives an individual signal. With this technique it is possible to run with more cars in one lane. Digital racing could be the future of slot car racing.