flashing running light

elektor july/august 1983 21 flashing running light Roadworks are usually marked during the hours of darkness by yellow flashing lights. These may often be linked together to form a "running" flashing light. Road diversions and the like are then clearly visible. The circuit described here provides a similar effect but for use in model roadways for instante. The speed of the "running" row of LEDs is determined by the fre- quency of the clock generator Nl. Depending on the type of IC used, this frequency will be of the order of 6 Hz ± 30% when potentiometer Pl is in mid position. The output of the clock generator is fed to the Johnson counter IC1. The outputs of this counter become logic 1 in sequence. The counter is reset to the start when 04 goes to logic 1. This explains the link between pins 15 and 10 of IC1.Outputs Q0 ... 03 are connected to four monostable multivibrator circuits consisting of N2 ... N5. The multivibrators are triggered by the negative going edge of the square ...