Count Down/Up Timer w/ IC's

[jmb4370]

I am trying to design a presettable count down/up timer using IC's with a 4 digit LED display, range 9.999 down to 0.000, the increment count is 0.001 seconds.

I am trying to decide whether it is better to use CMOS components like the 4029 up/dn synchronous counter into a 4511 7 segment display driver (com cathode), or the TTL components like the 7490 decade counter into the 7448 display driver? (I am not sure if the 7490 is actually an up/dn counter that can have a preset.)

What crystal would be best to use to get the clock input of the counters to be count at 0.001 second?

Michael

 

[blueroomelectronics]

I'm sure you've heard this ad nauseum in the forums. A microcontroller could do this unless of course you like wiring up a dozen or so ICs.

 

[jmb4370]

Hi Bill,

I started another thread with some different questions, and maybe you have some other input for me there. I do know the microcontroller would be way better, but I sort of want to do it both ways.

Here is the other thread:
https://www.electro-tech-online.com/threads/up-down-counter-with-relay-output.84937/#post657785

Michael

 

[blueroomelectronics]

I've not had to use TTL as building blocks for ages, since high school (and that was before PCs)