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Decade Counter

Elk

May 11, 2017
3
Joined
May 11, 2017
Messages
3
Hye everyone!
I was just exploring how a decade counter works.
Here is this simple circuit where I am giving the signal using a switch, and am using 6 LEDs. The reset has been connected to output 6 so that after the sixth LED, the counter re-initializes.
However, this circuit which looks alright to me, isn't even working.

I have already rewired the circuit twice, checked the connections, but nothing seems to work.

This is the link to the circuit picture:
https://drive.google.com/open?id=0B0X-NIVr5TsRenJPZ1BmaW9GSjQ

Sorry for the amateurish wiring! I have started electronics only recently.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Do you have a circuit diagram?

Presumably that's a 4017?

What is your power supply and which of the wires are positive and negative?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Do any LEDs light?

A problem that you will have is that a single press of the button may cause the counter to count anything from a few to dozens of pulses as keybounce from the button causes lots of transitions. Also, you need to pull the input to a definite voltage level via a resistor rather than leaving it float when the button is not pressed. The same is true of other inputs (of course, assuming you've got a CMOS 4017 chip.)
 

Elk

May 11, 2017
3
Joined
May 11, 2017
Messages
3
Do any LEDs light?

A problem that you will have is that a single press of the button may cause the counter to count anything from a few to dozens of pulses as keybounce from the button causes lots of transitions. Also, you need to pull the input to a definite voltage level via a resistor rather than leaving it float when the button is not pressed. The same is true of other inputs (of course, assuming you've got a CMOS 4017 chip.)

None of the LEDs light up. Gonna try your suggestion though. Thanks!
 

Audioguru

Sep 24, 2016
3,656
Joined
Sep 24, 2016
Messages
3,656
The circuit is too simple.
1) Pin 14 is floating but it MUST have a resistor to GND.
2) When power is applied, the counter can begin at any count. Maybe it begins at count 7, 8, 9 or 10 then your button will seem like it does nothing. Add a "power-up reset" circuit with a capacitor and resistor.
3) I agree that the button contacts will bounce many times when you push it and the counter will count all the bounces. Add a "debounce" circuit.
 
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