Pulse coded warning system for racetrack

Claim 1

A race condition alerting system for use on a race course to signal racing conditions to all of a plurality of racing motor vehicles proceeding around a closed loop race course, in which a race official monitors race course conditions and signals one of a plurality of conditions including a yellow flag or caution condition and a green flag or safe race condition, to be observed by the operators of said racing motor vehicles with one of said conditions being in effect at any time during a race, comprising: transmitter means transmitting a carrier which is modulated with a pulse coded racing condition signal to indicate a selected one of said conditions, including manually actuable means permitting the race official to select between said conditions according to the observed race course condition, radiating means for radiating the carrier over a range that encompasses the entire race course, an encoder that pulse encodes the modulated carrier according to an appropriate one of a plurality of preset codes corresponding to said race conditions, and timer means for supplying said pulse coded race condition signal to said radiating means for a predetermined transmission time; and a plurality of receiver units each including means for mounting in a respective one of said racing motor vehicles; antenna means to receive said carrier at all positions on said race course; a demodulator for demodulating said carrier; signal processing means following said demodulator for eliminating stray noise and passing the demodulated signal as a pulse coded signal; decoder means corresponding to the encoder of said transmitter, which includes presetting means preset with said plurality of codes corresponding to said race conditions and providing a plurality of output race course conditions signals when and only when the demodulated pulse coded signal matches an associated one of said preset codes; indicating means providing the operator with respective visible indications corresponding to at least said green flag and yellow flag conditions; and means for actuating said indicating means in accordance with said decoded output race course condition as provided from the decoder means, and maintaining the respective visible indication to the respective operator at least until another said output race course condition signal is provided thereto from said decoder means so that the operator is continuously presented with a positive visible race course condition indication at all times during the race.