Dodgems, or bumper cars, are small, electric- powered vehicles often found at amusement parks and fairs. Each car runs on electricity, with a motor powering a main drive wheel. How the motor receives the electric current differs across two main dodgem varieties.
The first type, and the oldest, is a conductive arena floor and ceiling array. In this setup, a metal mesh is embedded in the ceiling above the arena that supplies a positive polarity, while a series of metal strips across the floor supply a negative polarity.
A pick-up rod at the rear of the car and a brush beneath it complete the circuit – allowing an electrical current to pass into and power the motor.
The second system works in a similar way, but removes the ceiling mesh from the equation, supplying both positive and negative polarity from below. This is achieved by installing metal strips across the floor and separating them with insulating spacers, while also equipping the bumper cars with multiple pick-up brushes.
In the past, the chassis was often made from hardwood, but today they tend to be built out of plastic composites. Each dodgem is surrounded by a rubber bumper that offers passengers some cushioning from impacts.