0 99 counter circuit (74157 with timer)

Thread Starter

balkan

Joined Dec 20, 2017
10
hi guys i need help


I made the circuit in schematic again and again but it doesnt count.
i use 10uF instead of 1uF and I took the wave I wanted .

I dont know where to put the 5th entry (CLCK)on 74192 i try the 1, 0, and 3th entry on 555(Pulse output ) but it doesnt work.

I wanted to ask if there is a problem I cant notice.
 

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dl324

Joined Mar 30, 2015
16,846
Welcome to AAC!

For homework, you need to show your best effort before members can try to guide you to a solution.

What isn't working and what have you tried to do to fix the problems?

How much current can a 7404 source and how much are you expecting it to provide?
 

Thread Starter

balkan

Joined Dec 20, 2017
10
Welcome to AAC!

For homework, you need to show your best effort before members can try to guide you to a solution.

What isn't working and what have you tried to do to fix the problems?

How much current can a 7404 source and how much are you expecting it to provide?


555 192 192 157 7447
7404

this is how my board looks like i know its messy but im new and try to fix this for a days and im tired .

im sure my board and the schematic %100 same but it doesnt work.

i think 555 need for just 1 and 0 pulse . and looks like i got what i wanted .

and 5th entry of 192 and the 3rd entry of 555 should be connected(its upper counter input and every wave must be ++1 )

at least it finally gets stuck at 01 lol.

edit:not %100 i use 10uF instead of 1uF
 

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MrChips

Joined Oct 2, 2009
30,720
OK, I see the problem.
Your wires are too long.
I don't see any power supply decoupling capacitors.
What are you using as a power supply to power the circuit?

Disconnect the 74157, 7447 and LEDs from the circuit for now.
Use discrete LEDs and current limiting resistors and confirm that the 74192 counters are working correctly.
 

MrChips

Joined Oct 2, 2009
30,720
Put a 100μF capacitor across the power supply lines, i.e. from +5V to GND.

Put one 10μF capacitor from pin-8 to pin-1 on the 555-timer IC.

Put one 0.1μF capacitor from pin-16 to pin-8 on each of the 74192 ICs.
 

Thread Starter

balkan

Joined Dec 20, 2017
10
Put a 100μF capacitor across the power supply lines, i.e. from +5V to GND.

Put one 10μF capacitor from pin-8 to pin-1 on the 555-timer IC.

Put one 0.1μF capacitor from pin-16 to pin-8 on each of the 74192 ICs.
ok i will try tomorrow i hope its done.
if it fix i will post here.
Thanks for everything
 

absf

Joined Dec 29, 2010
1,968
What clock device are you using for the 'clock' input of the first 74192? Is it properly debounced?

Is the chip location in this picture correct?
20171221_021341_crop.jpg


Allen
 

Thread Starter

balkan

Joined Dec 20, 2017
10
7
What clock device are you using for the 'clock' input of the first 74192? Is it properly debounced?

Is the chip location in this picture correct?
View attachment 142138


Allen


sorry for flooding but there is a problem on my phone i cant edit msg

in the picture clck input was at gnd but i think it muat be connected with 3th output of 555 for debounce problem as u sayy
i tryed the all ways i think but it doesnt work


and yes locations correct.
the lamp on the ledt bottom for just the control the 555 cureenc
 

absf

Joined Dec 29, 2010
1,968
I dont know where to put the 5th entry (CLCK)on 74192 i try the 1, 0, and 3th entry on 555(Pulse output ) but it doesnt work.
in the picture clck input was at gnd but i think it muat be connected with 3th output of 555 for debounce problem as u sayy
i tryed the all ways i think but it doesnt work
You use very different terms to describe the pins on the ICs. We normally use Pin 5 of 74192 or Pin 3 of LM555. But you use 5th output or 3rd entry of the ICs. That's why it was very difficult to understand what you're saying.

Actually, what I was asking is this.....

balkan circuit.PNG
Allen
 

Thread Starter

balkan

Joined Dec 20, 2017
10
You use very different terms to describe the pins on the ICs. We normally use Pin 5 of 74192 or Pin 3 of LM555. But you use 5th output or 3rd entry of the ICs. That's why it was very difficult to understand what you're saying.

Actually, what I was asking is this.....

View attachment 142159

Allen
its connected to the 3th output of 555


as i say i dont know where it must be connected thats one of what im asking
i think it must be there
 

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absf

Joined Dec 29, 2010
1,968
Based on the 555 astable calculator in AAC here. The signal is very fast (about 7.2 Hz) using R1=150, R2=10K and C=10uF.

So the number is rolling and passing very rapidly causing unstable display.

You can either use another 555 and configure it as a 1 Hz astable oscillator OR just use a push button with a 10K connected to +5V as an input to Pin 5 of 74192 and see if that will work better.

Allen
 

absf

Joined Dec 29, 2010
1,968
I simulated your circuit in proteus and it worked ok but as someone in post #11 has indicated that you should not leave pins 4 & 11 of the 74192 floating.

balkan cct.PNG

Allen
 

Thread Starter

balkan

Joined Dec 20, 2017
10
I simulated your circuit in proteus and it worked ok but as someone in post #11 has indicated that you should not leave pins 4 & 11 of the 74192 floating.

View attachment 142161

Allen
i use another 555 to get 1hz and chech the 192's 4th and 11 it works.

but another problem its count only odd numbers count
to 11-99 only odds.

edit : s
when i restart the supply its change. right one count 1 3 5 7 9 left one sometimes count odd sometimes stuck at 4 not stable
 

Thread Starter

balkan

Joined Dec 20, 2017
10
when i plug power cables in and out its stuck.

but if i both 192's 11th cables gnd to 5v adnf after again gnd it work.but still count only odd numbers and i checked cable connections are correct.
could there be another problem maybe with the jumper cables or i missed someting else again
 
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