i have designed this to count from zero to 10 up and down ,

so i connected it to another stage ,

my problem is : what if i need to adjust it to stop at "60" and then count down ,

please tell me how to do that

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Put a binary 6 on D0, D1, D2 and D3 of U2. It looks like you leave pin 11 normally open but ground it to load the 6. Then open again to count.

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i did as you told me ,

D0 and D3 to GND ......D1 and D2 to 5v .......so i have 0110 = 6

whan i connected pin 11 to GND second U2 , the seven segment the second one showed 6 all the time , and the counting process doesn't work.... the first stage is working well.

current state U1 pin11 to 5v
U2 pin11 to GND ( what's wrong )


thank you

 

I think that the counter that you have counts up from 0 to 99 and then resets to 0, or counts down from 99 to 0 and then resets to 99.

Do you want to count up to 59 like the seconds counter?

If so, you need an AND gate and a NAND gate.

The NAND gate detects "9" on the output of U2 and preloads it to 5. Connect the inputs of the NAND gate to Q0 and Q3 of U2. Connect the ouput of the NAND gate to the NPL line (pin 11). Connect D0 and D2 to high, and D1 and D3 to low.

When the count reaches 9 it will be immediately forced to 5.

The AND gate detects "6" on the output of U2 and forces it to 0. Connect the inputs of the AND gate to Q1 and Q2 of U2. Connect the output of the AND gate to the MR line (pin 14).

When the count reaches 6 it will be immediately forced to 0.

 

thank you , i did that , it works very well