Wiring circuit

The decade counter-barrier CD4017 has 10 outputs, for all low to climax transition next to the control input, rising skirt, the counter advances single LED. in the same way as untaken one extensive ball the the foremost LED illumination again and it goes on. You can vary the respect of R2 100K Linear potentiometer to construct LEDs run fast or else slow on the uptake. The frequency of oscillation of astable 555 is known having the status of f = 1.44 / ((R4 + 2 * (R2 + R3)) * C3)

The 10 outputs come up with 10 sour LEDs. The current thru the LED is partial by R1, the current can be there calculated like this (9V - 1.6V) / 1K = 7.4mA this is inside 20mA which is the danger limit of the CMOS output. You lack it to be sharp wear and tear transistors pro each output.

The cap C1 is a filter and C2 is to prevent racket by the side of pin 5 influencing the output like it is a control voltage item.You can cascade or else attach many extra counters with the CO or else incorporate on show pin 12 of 4017. The pin 15 reset is reserved next to low in favor of as well as, on above what is usual it wish reset the counter but is not used fashionable this circuit.