multiply circuit?

I have a /3 then /5 circuit (4017, 74HC90) for reading Rev/S on a pump shaft. Now I have a new indicator which cannot be changed, that must see 4 signals per revolution. The exciter is 35-1 teeth. Can I multiply by four? I apologize, I have not had formal training in this field.

Thank you very much

 

[nbucska]

Yes, you can, using e.g. 7497 rate multiplier.
If I understand, you divide the output by 3 and then by 15
-- i.e. alltogether by 15 --.

In this case you could get more evenly distributed pulses
by taking the signal before dividing by 5 and skip
one of five pulses.

Do you get 35 pulses/rev ? in this case you must divide by
7 and 5 -- i.e.35 -- not by 3 and 5. In this case it would
be better to divide by 9-9-9-8.

If you need more, E-mail more info <nbucska@pcperipherals.com>

 

It is indeed /7, not 3. My fault. I thank you very much for your help. I will look into the rate multiplier. Thank you.

 

[nbucska]

It is better to use input/7 and do a divide by 9-9-9-8.
This will give to you allmost evenly spaced pulses.

Want a sketch? Send FAX#. <nbucska@pcperipherals.com>

 

I sent you an email. Let me know what you think. My fax is in there so if you have time, a sketch would be great.

Thank you