running light and decade counter

here is a very interesting circuit . this circuit uses a 555 timer chip and a decade counter CD4017.

here the timer ic 555 is configured as astable multivibrator. ie the output of the timer ic gives continuous pulse. about timer. the 555 timer ic is the very popular ic. in short it has two mood of working. one is called monostable mood and another is called the astable multivibrator mood. monostable gives the logic high output only once. but the astable multivibrator gives square wave or the high- low pulse several times. about decade counter the decade counter is an ic that count the input pulse and it gives output sequentially. when first input logic high is sent from the timer ic to the input of the counter, the first output led glows. when second logic high is sent to counter ic then first output put out and the second will glow. in this way the running light work. note: for timer 555 -> 8 pin is +ve suppply -> 1 pin - ve supply for 4017 -> 16 pin is +ve supply -> 8 pin is -ve supply. if you have any difficulties and question about this circuit, dont hesitate to post the comment