# 4040 12-bits Counters

Discussion in 'General Electronics Chat' started by Olakunle, Mar 13, 2011.

1. ### Olakunle Thread Starter New Member

Mar 12, 2011
3
0
Dear sir,
I want to read a frequency counter values with visual basic.
I need 1s i.e 1hz from a 4mhz crystal and I have 2 4040 12-bit counters.
I can divide each counter by 4096. The problem is that I need to divide one
4040 by 4000 and the other by 1000 to get 1s.How should I divide by 4000 and 1000
using AND Gates etc with the Counters?

2. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
Have you got data sheets? CD4020, 4040, and 4060 can all give shorter than maximum counts.

3. ### Ron H AAC Fanatic!

Apr 14, 2005
7,050
657
But they can't divide by any number that is not a power of 2. You can use a 4.096MHz crystal, or a 1.024MHz crystal, or 32768Hz crystal, or... any crystal whose frequency is a power of 2.

4. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
1000 = 1024 - 24. 24 = 16 + 8.

4000 = 4096 - 96. 96 = 64 + 32.

5. ### Ron H AAC Fanatic!

Apr 14, 2005
7,050
657
I forgot about decoding and short-cycling the counter.
You can divide by 4000 with a CD4020, an 8-input AND gate (CD4068), and a couple of inverters from a CD4049.

6. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
Ah, but can the OP see the way to decode with the least logic?