Hi, Hafi2_07 here is the circuit, I tried to upload last night but my ISP had problems.
The cct is built and tested. it counts up and down from 00-99 backwards or forwards. It keeps the count or you can keep counting while FL is displayed.
It resets to 00 if you wish. I had to use 4029's as I could not get 4510's.
i used a 555ic to develop a pulse for counting as the switch was very noisy and cused extra pulse to be counted. r 555/2 and c555/1 can be altered if your switch is extra noisy. I selected these values to give a fast reliable count. If you really are counting very fast then yo can probably lower these values. C switch delay 22UF is to allow the display to blank before displaying FL.
More experienced persons will probably find more elegant ways to do some things, but this circuit works well as it is. I have built and tested it.
Enjoy, btw what will you use it for and what does FL stand for.
As I said before the cct is reasonably simple but the construction is a "bitch".(About 140 solder joints)

Cheers RH

Attached Images

	counter4.jpg (148.5 KB, 80 views)
	counter backview.jpg (90.8 KB, 52 views)
	counter front.jpg (46.5 KB, 56 views)
	flview.jpg (64.2 KB, 44 views)

 

tnx for the great effort

what other ICs cn i use??

is it ok to use ne555n?74ls192? because the availability of these IC in my place is rare

 

thanx retiredHAL....i think u r really smart in electronics...

i'll try this circuit and then will inform u later....

thanx very much

 

to...retiredhal

-- can you help me on the crct of 74ls192
--my problem is to design crct 00-99 up down counter.....

 

Dican, sorry, I have never used a 74lsxxxx IC so I would be giving you the wrong info. However, apart from the voltages there should be no problems using 74Ics as they are basically the same (I believe). The cct using 4XXX ICs works. Substitute the equivalent 74xxxx IC (look at the data sheets) and you should be able to construct the same. OR use the the cct I supplied --- it works!!

NB, I had never used an 4000 IC before this project (up/down counter) so I learned using the data sheets. It really is not so difficult and there are any number of 555 IC tutorials to help you to "debounce" the switch.(stop it from counting noise pulses) and give the wrong count. (I used this project as a learning experience for my next project) I learned a lot. Give it a go yourself.

Cheers RH

 

hi...i need some explanation from u guys....i have attached the figure...i want to know how this circuits is working

p/s: sorry to reply at this thread...want to open new one...but i cannot open....

 

is it possible for this circuit to count up and count down depending on a varying frequency.. like when frequency increases the count increases n when it decreases the count decreases???