preset the binary counter cd4516

Thread Starter

ouafae

Joined Jun 11, 2019
52
hello,

I am in internship, my mission is to build a generator, I need to preset the binary counter cd4516.
I know how to make it count from any value. But I don't know how I can stop it at any value !!!???.

Please, can someone help me?
 

ericgibbs

Joined Jan 29, 2010
8,755
hi o,
Please post a drawing of your attempt to solve the problem, we can then guide you.
What range of count values do you want it to stop..?
E
 

ericgibbs

Joined Jan 29, 2010
8,755
hi,
You said you know how to preload the 4516 to a count of 4.??
Look at this clip from the datasheet of the 4516, you know its a Binary counter, so which Qn output pins will add up to Decimal 10.?
E
4516.PNG
 

Thread Starter

ouafae

Joined Jun 11, 2019
52
I didn't quite understand your question.
yes I know how to preset the counter to start for example at 4, i. e. I receive a count from 4 to 15 (4 5 6 ... 15) at the output
I want me to stop at 10. I thought about adding a NAND but I don't know if I'm in the right direction
 

ericgibbs

Joined Jan 29, 2010
8,755
hi,
OK.
Look at this image of the 4516 Qn outputs as it counts, I have highlighted the Decimal 10 count, which Q outputs are Logic High and which are logic Low for the 10 counts.
When you know which Q's are High and Low for 10, then we can look at AND/NAND gates.
E

4516_outputs.PNG
 

ericgibbs

Joined Jan 29, 2010
8,755
OK,
The Binary Weighting for that 1010 is 8 4 2 1
So what would you get, if you connected a two Input NAND gate to the Q outputs for Decimal 10..???

Edit: changed the Bin 10 to Deci, 10 in case it confused you.
 
Last edited:

Thread Starter

ouafae

Joined Jun 11, 2019
52
it depends on what I choose as an entry.
if I choose Q1 and Q2 as NAND input I will get 1 at the output
 

ericgibbs

Joined Jan 29, 2010
8,755
if I choose Q1 and Q2 as NAND input I will get 1 at the output
hi,
You have already said Q2 and Q4 are High when you posted 1010 Binary.
Which is:
Q4=1
Q3=0
Q2=1
Q1=0
Equals Decimal 10

So why would you want to use Q1 and Q2.???

E
 

ericgibbs

Joined Jan 29, 2010
8,755
OK,
So which Q outputs will you connect to the NAND gate input.?
I guess you know that when a NAND has all its inputs High =1, the Output is Low=0.?

E
 

Thread Starter

ouafae

Joined Jun 11, 2019
52
if I take Q4 and Q2 I will get 0 at the NAND output.
if I connect this output to branch 1 of the circuit it will stop the counting !!!!??
 

ericgibbs

Joined Jan 29, 2010
8,755
hi,
The Q4 and Q2 are correct.
I do not know what you mean when you say 'branch 1' of the circuit.??

You should have a simple diagram or photo you could post, so that I can see the remainder of the circuit.
E
 

ericgibbs

Joined Jan 29, 2010
8,755
OK,
You would use the NAND gate output into another gate which has the clock on one input and the NAND gate output gate on the other, this would stop it counting.
So when the count gets to 10 and it stops counting, what do you want to happen next.?
 

Thread Starter

ouafae

Joined Jun 11, 2019
52
my goal is to vary the frequency with a specific step. to do this I need this counter to preset cd4059 to have N=034, 134, ..., ..., 1034.
when it stops counting, I switch to another frequency range. That's all to do EMC tests.
 

ericgibbs

Joined Jan 29, 2010
8,755
hi,
Would recommend that you check out the free LTSpice simulation program, it can simulate Digital circuitry, it could be useful in your project.
E

EDIT:
Added a simple/basic LTS example.
 

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