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

 

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?

 

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?

 

Will the counter stop when I connect CPD to Gnd?

What does it say in the datasheet?

 

What does it say in the datasheet?

It says no change.

 

You must be looking at a different datasheet from mine.

 

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).

 

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.

 

Draw the truth-table of an AND gate.

 

Chill out. I am not doing his homework.

I am only asking to identify the pin which will achieve a certain result.

 

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).

Draw the truth-table of an AND gate.

Hi will this modification stop the timer?

 

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

 

Why did you start another thread? This one is for the same problem:
https://forum.allaboutcircuits.com/threads/how-to-stop-a-counter.165858/

If you want help, you need to do some work. Tell us what your proposed circuit isn't doing.

Merged:

 

Hi will this modification stop the timer?

Check your wiring. What do the connections in the red regions do?

 

You cannot drive a buzzer from a logic gate and still expect the logic voltage to be a valid logic HIGH.