Methods of operating field emission displays are disclosed. The conversion circuit converts user data b1, b2, b3. A plunger and needle are slidable between a first position in which the plunger and needle are slidably disposed in the barrel and a second position in which the plunger and needle extend from an opening in the end of the barrel. The rails can be pivoted down to divert patties for clearing jams. A method of manufacturing a vehicular horn system includes connecting a prong to a base, connecting a steering wheel to a steering column that extends through the base, and positioning a carbon-based contact at an end of the prong to be in electrical contact with the steering wheel.