Decade counter to stop on 10 using 7-seg displays and produce a continuous drive to a buzzer?

Thread Starter

ScrotalRecall90

Joined Oct 17, 2019
5
Hi,
Please forgive me as I am new to electronics, but i want to implement continuous drive/power to a buzzer when the 7-segment displays produce 10 [1] and [0]. And either stop or continue counting when the buzzer is continuously sounding.

The following link takes you to the circuit I am thinking of using and wish to implement this:
https://circuitdigest.com/fullimage?i=circuitdiagram/Object-Counter-Circuit-Diag.gif

Many thanks
 

dl324

Joined Mar 30, 2015
9,121
Welcome to AAC!
And either stop or continue
counting when the buzzer is continuously sounding.
What controls whether or not the counter counts when the buzzer is sounding?

For future posterity - circuit in question:
upload_2019-10-17_16-43-35.png

The voltage regulator is unnecessary. Save the power it wastes and just adjust resistor values accordingly.
 

Thread Starter

ScrotalRecall90

Joined Oct 17, 2019
5
Hi, thanks for the reply.
Sorry i miss read, so i have amended.
I would like to implement a buzzer that comes on and stays on when the displays reach 10.

Apologies
 

Yaakov

Joined Jan 27, 2019
1,601
Is this just an experiment or does it have an application? If the latter, could you describe the problem it is intended to solve?
 

djsfantasi

Joined Apr 11, 2010
5,687
I’d use one decade counter and a bcd to 7 segment decoder. The carry output of the counter does three things:
  1. Stops the clock, preferably with a clock enable pin
  2. Display a 1 on the second 7 segment display (two segments with a driver if necessary).
  3. Is used as an input to a driver (BFT or MOSFET), to sound the buzzer
You need two buttons: a start button and a reset button.

The start button will be gated with the overflow output to pass to the clock enable pin of the counter or to a clock control circuit.

The reset button resets the counter. Which also clears the overflow pin.
 

absf

Joined Dec 29, 2010
1,942
4033 stp at 10.PNG
I would use two AND and a NOR to detect '0110' on the A-D segments of the tenth digit.

This is to avoid the confusion of digit "0,3,8,9" where A-D is '1111' , digit "7" where A-D is '1110'. where only A-D is '0110' needed.

The output would switch on a NPN transistor thus the buzzer.

If you want to stop the counting pulse from 555, the same output would be inverted (using one of the NOR gates) and connected to the Reset Pin of the 555. The 555 would have to tie High through a 10K resistor.

Allen
 
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dl324

Joined Mar 30, 2015
9,121
I have edited my post in response.
Don't know how you were able to edit the post and not have that reflected, but a note on forum etiquette. It's not nice to edit a post in a manner that makes a response to the original post seem clueless.

If you force the circuit to reset at power on, or are okay with using a reset switch if it doesn't, you can use the rising edge of the carry out from the first counter to trigger a flip flop. Whatever you use to reset the counter will also have to reset the flip flop.

The flip flop would also have to disable the 555 timer.
 

djsfantasi

Joined Apr 11, 2010
5,687
Update: Ok, nevermind!

Ignore this post

Don't know how you were able to edit the post and not have that reflected, but a note on forum etiquette. It's not nice to edit a post in a manner that makes a response to the original post seem clueless.

If you force the circuit to reset at power on, or are okay with using a reset switch if it doesn't, you can use the rising edge of the carry out from the first counter to trigger a flip flop. Whatever you use to reset the counter will also have to reset the flip flop.

The flip flop would also have to disable the 555 timer.
P pm

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Thread Starter

ScrotalRecall90

Joined Oct 17, 2019
5
Thank you all ever so much for your help and knowledge shared :)

And thank you for pointing that out, note taken.
Don't know how you were able to edit the post and not have that reflected, but a note on forum etiquette. It's not nice to edit a post in a manner that makes a response to the original post seem clueless.
Is this just an experiment or does it have an application? If the latter, could you describe the problem it is intended to solve?
Its for a scenario exercise that requests a that a counter with a buzzer is implemented onto pcb production line that will count any rejects that pass and sound an alarm when 10 rejected circuit boards have passed. Hence why I was drawn to the example circuit I posted above which contains IR LED's.

I really appreciate all of your help and understanding with me being new to this:)

Pat
 

dl324

Joined Mar 30, 2015
9,121
Its for a scenario exercise that requests a that a counter with a buzzer is implemented onto pcb production line that will count any rejects that pass and sound an alarm when 10 rejected circuit boards have passed. Hence why I was drawn to the example circuit I posted above which contains IR LED's.
Then you don't need the 555 timer.

What is the circuit supposed to do after 10 boards have been rejected? Stop counting, shut down the line, and send everyone home?
 
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