slot-car controller - an economical power source for model car race tracks that also improves the realism by using pulse width control

29 slot-car co tro"ller Some things seem destined never to lose their appeal. Model trains, for instance, are a continuing source of fascination for many people, both young and old. Not quite in the same league, but none the less always popular, are model car racing tracks. The most common of these, called "slot-cars" after the slot used to guide them, come in many different guises with the cheaper versions being battery- powered. We all know how quickly these batteries run flat but, being "electronically minded, the solution is obvious. The problem with battery-powered equip- ment is that this power source is short- lived and expensive. Often lack of space dictates the use of batteries but in many other cases this is decided purely for economic reasons. One such situation is slot-car games. Battery-powered versions are much cheaper to make (and to buy) than those with a mains supply. After pay- ing for the twentieth set of batteries within a week, however, the cheapness of this s...