I am lost ,, plz help : Design a digital circuit ?!

[ee-28]

hi,
i am from dubai university , our professor gave us a project that no one can solve.
maybe you gays can help me ?!

Design a digital circuit that can be attached to a school bill which can work automatically
from 7:00 AM to 12:45 PM, and it has the following features
1- Rings for 5 seconds.
2- Start ringing 7:00 AM to announce for the field gathering.
3- Rings 7:20 for going to class.
4- Rings for the start of the first class period at 7:35 AM.
5- Rings for end of each period after 40 minutes from its start.
6- Rings for break after 10 minutes from the end of the previous period to announce for
the next class period.
7- After the third period, a break of 30 minutes.

thankx

 

[ericgibbs]

hi,
i am from dubai university , our professor gave us a project that no one can solve.
maybe you gays can help me ?!

Design a digital circuit that can be attached to a school bill which can work automatically
from 7:00 AM to 12:45 PM, and it has the following features
1- Rings for 5 seconds.
2- Start ringing 7:00 AM to announce for the field gathering.
3- Rings 7:20 for going to class.
4- Rings for the start of the first class period at 7:35 AM.
5- Rings for end of each period after 40 minutes from its start.
6- Rings for break after 10 minutes from the end of the previous period to announce for
the next class period.
7- After the third period, a break of 30 minutes.

thankx

hi,
Look at this School Bell circuit for a previous Thread.

As its a School project, you work out the changes required and post your circuit for checking.

 

[ee-28]

thank you so much ,

Seems a little complicated
I think there is a better way to design by IC 72555 ! am I right ?!

 

[JimB]

Seems a little complicated

A complicated problem often needs a complicated solution.

I think there is a better way to design by IC 72555 !

Then show us your solution using a 555 timer.

am I right ?!

No, you are totally wrong.
For one thing, a 555 is not suited to time periods greater than about 1 minute.

JimB

 

[ljcox]

You need the design a modulo 60 counter for the minutes & a modulo 24 counter for the hours.

Then design gating to detect the times of each event and provide appropriate outputs.