hi..i'm working with the counter project now..i'd like to design up/down counter circuit with number 0-99....the circuit must have up switch and down switch...

ex: initial zero...push switch up...display '1'....and push again, displays '2' and continuous.....then whwn i push down switch....the counting should be decrease...say that i'm at 30 now..when i push it..the counting will be '29' and the process countinous....

another switch is when we push it..the 7seg will display 'FL'.....

any circuit..??plz up if you have....also up the thread/link/website with the similar project..tq

 

hi,
Your project could be solved by using a small PIC controller, something like a 16F628A.

If you are able to use a PIC, let us know and we can link you to a thread.

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PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

You can also make an U/D counter using a 74LS192, a synchronous binary U/D counter. If you don't need the preset values just don't wire them. Keeping "up" input high and clocking "down" input it will count down and it will count up keeping input "down" high and clocking "up". They can easily be cascaded by using "carry" and "borrow" outputs to clock the next stage.

A 74LS47 will decode the 4bit binary outputs to seven segement common cathode displays, using a 74LS48 the sixes and nines will have tails.

 

hi,
Problem is, the OP wants some non numeric symbols displayed.
As you say, the rest is fairly easy to do.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Hafi2 . You said you only wanted to count 00 - 99 and display "FL" .
That means you only use TWO 7 segment displays. The BCD/Decadic counters will do the counting for you. Displaying of "FL" is probably most easily achieved by making your own matrix of diodes to address the required segments. Eg F would require to address segments A,F,G,E and L would require segments F,E,D . If you require more letter combinations eg LS or HC it will become much more difficult (lots of diodes) and be aware that you cannot display all characters with a 7 segment display. EG an A will be the same as an R. And a Q or T is impossible, but you probably already thought of that.
A 4510 will do the counting in BCD up/down and a 4511 will decode the the BCD to drive the segments in the display.
More experienced members can probably suggest easier ways.
Cheers
RH

 

Supposedly he is not an egytian and wants the display in hyroglyphes. What about counting up to "29" as posted and then reverse the direction to count down?

 

hi boncuk,
No problem with the decimal up/down, 00 thru 99, its the 'alpha' characters where he will need extra decoding to light the LED segments for 'FL' etc.

Why dont you post a circuit diagram for him..?
For glyphes, I would use a 8 * 8 LED matrix.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Hi Eric,

I must admit that I didn't understand completely what was meant "using another switch". The way I understand it the extra switch has to take care of the letter indication. If it's just that there isn't a problem to post a circuit.

That one uses one common current limiting resistor. If he has more money to spend he might use separate resistors for each LED.

 

my project still not working.....i've construct the circuit using multisim....but not working...anyone else could help me..???i have little knowledge in electronix....so complicated explanation sometimes i not understand.....

 

hi
i just wana ask that,if i want to design up/down counter till 1,000....then how is it possible......then should i cascade 74LS47 ICs?....please reply as early as possible

 

ei,..anyone please HELP me,.i need a schematic diagram of counter 00-99 7segment display,.please pm me or email me at eiluj_872001@yahoo.com,.tnx,...,.
,.i need it asap,..

 

download simulator first and install
http://my.ece.ucsb.edu/bobsclass/2C/...cuit_maker.htm
then download
attach file " counter.txt " and rename to "counter.ckt" open with simulator(circuitmaker).

Counter.txt

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Hafi2 07
I have a cct for you, sorry I took so long Ive been on holidays but I wanted to build it so that I would not give you a cct that did not work. It counts up and down from 00 to 99 and has a reset to 00. Tomorrow I will get on the FL part. The question is do you require to keep the count when you display FL? or do you display FL and do a reset to 00?
By the way although the cct is reasonably simple. the actual construction is quite difficult, roughly 100 -120 connections to solder depending on which way you route the connections.

Cheers RH

 

thanks retiredHAL.... i am require to keep the counting....and not reset to 99...thank u for replying....

for others..thanks also....i have try out foe several circuits....unfortunately they are never works....

retiredHAL...thanks foe helping me...

 

counter schematic
counter.PNG

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