Help with 555 + 4017 Circuit

Hey everyone,

I'm new to this forum and an Electronics student. We're trying to make a board-game timer using a 555 IC timer. I wanted something different compared to my peers, therefore i went on google and searched up the 4017 Decade counter. However using crocodile clips 6.0 I couldn't get it to work the way I wanted it to. I tried changing the push to make switch that lead to pin 2 into a signal generator to provide constant signals so the LEDs would light like a countdown from 10 seconds to 0. This did not work. Any thoughts to help fix this?

Thank you, sorry If my question was a little amateur (I'm only a freshman)
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μZiQ said:

to provide constant signals so the LEDs would light like a countdown from 10 seconds to 0. This did not work. Any thoughts to help fix this?

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you mean, you need a devide by 10, or 9 or 8...counter? for above configuration of 4017 providng a 1Hz input will make the LEDs to light from out-0 to out-9 then back to 0. if you need a devide by operation for example divde by 8 then connect out-7 to reset, now you will see all of the out puts goes high every 8 sec.

if your requirement is different, explain little more...

Yeah I would like the LEDs to light from out 0 to out 9 with a one second delay. Which pins should I connect to and why? Crocodile clips just does not label the pins clearly and I need to design this circuit on this program.

First: This is a 555 Timer data sheet.


Second: This is a 4017 decade counter divider data sheet.

Those links should help you with the pin out.

You are using the 555 as a clock running it as an astable multi-vibrator. If you want to increment the 4017 up one count every second you want the 555 to run at 1 Hz. The question now becomes exactly what you want the 4017 to do? The 4017 will increment 1 count for each input pulse 0 through 9 (10 counts). Do you want it to count to 9 and halt or count to 9 and recycle?

Ron

A pushbutton contact bounces each time you push it and each time you release it. Then its output is many pulses, not just one. You need a "switch debounce circuit" for a pushbutton to be used as a clock signal.

You have the 555 wired as a monostable. Instead you should wire it as an astable oscillator for it to clock the 4017 by itself without a signal generator and without a pushbutton.

You need to plan how to stop the 4017 when it finishes a countdown (using the enable pin).

Per AG if you plan to have switches other than on/off for power you need to use switch debouncing. I have attached what I think you are after using a 555 with adjustable frequency configured as a free running astable oscillator and what the results would look like with LEDs. Also, in your posted circuit you do not need a resistor to limit the current to each LED. Using a 4017 there will only be a single LED on at any given time.

Anyway, I think the attached is what you are looking for.

Ron