4017 decade counter /eight LED's

Richard's picture


Joined: Jul 20, 2016

Replies: 0
4017 decade counter /eight LED's
July 20, 2016 - 5:42pm

I assembled the simple 4017 counter circuit for lighting LED's in sequence.  Something is amiss  When I push the button to give the 4017 a pulse,  instead of LED's lighting in sequence, all LED's light up.   I have checked,  double checked, and triple checked, and all connections seem to be correct.  The only deviation I made is using a 9 V pwr. source instead of 5V, and have not yet connected the 100uf capacitor across the pushbutton switch for "bounce" prevention.   Could either of those two deviations cause this?


Abhishek's picture


Joined: May 19, 2015

Replies: 403

Are you following this Decimal Counter Circuit, if not then please follow this circuit.

9v battery is fine, and removing capacitor can only affect the sequence of glowing LEDs, means they may glow unexpectedly, but glowing all the LEDs at the same time cant be the case. If all are correct according to the above suggested circuit, then your 4017 may be faulty, please try replacing it.

And generally 555 IC is used to give it clock pulses, you can check lot of circuits of IC 4017 and 555 here.