A 3 digit Counter

[marwiz]

Hey guys
i want to make a counter that counts down from 470 to 0 whenever the
switch is activated

where do i start????
i'm clueless??

email me
[email protected]

 

[Lou]

Hi

You could use 3 presettable U/D counters in the down mode. You preset
them at 470 or whatever value and you clock them at the rate you want
as soon as the preset enable input is released. If you need to display
the counting, you have to add decoders and a display.
Example ICs:
Counters: CD4510
Decoder driver: CD4511