Hello All,
I'm new to the forum and I'm having trouble with a university project. I am using a 555 timer, four 74192 up/down counter chips, four 7447 displays, and four 7 segment displays to function as a 24 hour clock. The part I'm stuck on is I've never used these chips to count up to a certain number and reset back to zero before. What I'm used to is starting at a preset number and counting down to zero.
So this is how I imagined it would work:
1. 555 pulses every minute and sends a signal to the first 74192
2. The first 74192 chip is preset to 9 and the 1 minute pulse is sent into the Up clock pin
3. While the 74192 chip is counting up it sends the data to 7447 and seven segment display
4. When the 74192 chip hits reset after 9 it sends a carry pulse to the second 74192 chip
5. The second 74192 chip starts at zero and counts up to 5 then resets to zero.
Similarly the other 74192 chips will be preset and connected through carry. Max readout should be 24:00 and min should be 00:00
So far, I have the first 74192 chip counting up to 9 and pulsing to the second 74192; However, the second 74192 is going 0 1 2 3 4 5 6 7 8 9 on the first cycle and then 5 6 7 8 9 0 on every cycle afterwards. Why is it not working like the first 74192?
I'm new to the forum and I'm having trouble with a university project. I am using a 555 timer, four 74192 up/down counter chips, four 7447 displays, and four 7 segment displays to function as a 24 hour clock. The part I'm stuck on is I've never used these chips to count up to a certain number and reset back to zero before. What I'm used to is starting at a preset number and counting down to zero.
So this is how I imagined it would work:
1. 555 pulses every minute and sends a signal to the first 74192
2. The first 74192 chip is preset to 9 and the 1 minute pulse is sent into the Up clock pin
3. While the 74192 chip is counting up it sends the data to 7447 and seven segment display
4. When the 74192 chip hits reset after 9 it sends a carry pulse to the second 74192 chip
5. The second 74192 chip starts at zero and counts up to 5 then resets to zero.
Similarly the other 74192 chips will be preset and connected through carry. Max readout should be 24:00 and min should be 00:00
So far, I have the first 74192 chip counting up to 9 and pulsing to the second 74192; However, the second 74192 is going 0 1 2 3 4 5 6 7 8 9 on the first cycle and then 5 6 7 8 9 0 on every cycle afterwards. Why is it not working like the first 74192?