How to stop a counter?

Thread Starter

alvinteoo

Joined Dec 21, 2019
9
Hi people

I need to create a count up timer from a preset count 40. It will display the remaining time on two 7 segment display PCB. It will sound the buzzer when the count ends. The timer will stop when the time is up. However, I am not too sure how do you stop the timer when the time is up.

Please help me!!!
Thank you :)
 

Attachments

djsfantasi

Joined Apr 11, 2010
5,913
If you are counting things, how do you know when to stop counting? This may sound like a silly question, but humor me... and answer it.

I can think of two different answers and I’ll give you one. Someone tells you to stop counting. What pin on the 74192 tells the chip to stop counting?

There is another obvious answer. Can you figure out what it is?
 

Thread Starter

alvinteoo

Joined Dec 21, 2019
9
If you are counting things, how do you know when to stop counting? This may sound like a silly question, but humor me... and answer it.

I can think of two different answers and I’ll give you one. Someone tells you to stop counting. What pin on the 74192 tells the chip to stop counting?

There is another obvious answer. Can you figure out what it is?
Will the counter stop when I connect CPD to Gnd?
 

djsfantasi

Joined Apr 11, 2010
5,913
Another obvious answer is to stop the clock.
Which means that if I ground the 555’s pin (x), it will stop.
From the datasheet, identity pin (x).
FYI, this is NOT “Homework Done for You”. Members should NOT provide a solution, but lead the TS to his/her own conclusions. Compare your post to mine. We were both saying the same thing.

Update: my eyesight misread his post. I thought he had identified a specific pin.
 
Last edited:

Thread Starter

alvinteoo

Joined Dec 21, 2019
9
Hi people

I need help regarding the below-attached circuit design. I am not too sure if my modification of the circuit will make the timer stop when it reaches the last count. Please help me!! Thank you :)


Problem Statement:

To build a count-up counter that counts from 40 - 99. At the end of the count, the buzzer will sound off and the timer will stop.

Components:
74192 IC
7 Segment PCB Display
Push Button
Resistor
NAND Gate
AND Gate
NOT Gate
555 Astable timer
 

Attachments

Top