newbie needs help with presetable count down timer 7 segment

[zenton]

Hi,

I am trying to build a electronic scorer for Judo competitions.

I need a circuit diagram for a single super bright 2.3 inch 7 segment display (each segment is 2.5 V) that is to count up once each time a button is pressed and then reset to zero using another button. (I will need to repeat this circuit 8 times for different scores and penalties)

I also need a circuit diagram for a count down timer using three 2.3 inch 7 segment displays first display in minutes the other 2 for seconds. The timer needs to be preset to either 5 minutes, 4 minutes, 3 minutes or 1.5 minutes. The timer also has to have the ability to be paused (during a delay in the competition) and at end of fight reset to zero. (This is for the the main match time)

I also need a circuit diagram for a count down timer using two 2.3 inch 7 segment displays both for seconds. The timer needs to be preset to either 25 seconds, 20 seconds or 15 seconds. The timer and at end of hold down to be reset to zero. (This is for hold downs that occur during the main fight time)

I know nothing about programming PIC's or have the equipment to do so.

Any help no matter how small would be a great help.

Thanx zenton

 

[hotwaterwizard]

How about this circuit?
Complete Project Located at this Website

**broken link removed**



**broken link removed**

 

[mechie]

Count-down timers

Have a look at ...


This is a down-counter with 4 digits - you could simply miss the 10-minutes bit out of the logic and fit single colour LED displays (this circuit changes the colour of the display if you freeze (pause) it.

If you follow the link and then go back through the thread there are some photos of the circuit working on a breadboard, it is a tested, proven circuit.
8)

 

[zenton]

Thank you Mechie and hotwaterwizard

Mechie and hotwaterwizard the circuits you posted are exactly what I was looking for.

Thanx heaps zentonT