Help needed on how to preset the CD4510 BCD up/down counter to any
digits. I am looking
for a 2 digits 7 segment count down timer circuit. Please help.
You would need two of them, and some dip switches or hardwired preset
inputs to set the "count from" digit. Or if you want to get fancy -
there are decimal thumb wheel switches that read the digit 0-9 and
output the BCD code - or you can just get a ten position rotary switch
and do it yourself with steering diodes.
The outputs have to be sent to a decoder, driver (can be in a single
package usually including a "latch" to hold the count input
temporarily)
http://www.play-hookey.com/digital/experiments/counter_display.html
Gives the basics
Your display driver would depend on whether you want Common Cathode or
CA display LEDs or an LCD display.
This stuff is really easy to do - just a few data sheets and some
think time - and it has been presented in thousands of hobby articles.
Search.
