3 digit up down counter

[frenchneco]

here's the circuit.

 

[ericgibbs]

yes! we finally figured it out. we were just so stupid to see it. the voltage in the display is just high. the preset voltage drop in the multisim program is 1.66V.

we also got the other digits figured out, which came easy since you helped me. we were just laughing at ourselves after, since it was not hard at all. but the only problem is the starting count is not "000". it would either display "999" or "001". we're thinking of connecting it first in the reset? any suggestions?

hi,
Looked at your circuit, as you switch ON, the 555 is probably putting one count into the 1st LS193. Do a manual RESETafter power up or add a Resistor/Capacitor RESET to clear the counters on power up.

 

[Roomi]

Hi frenchneco, U can get free samples of ICM7217 from MAXIM......

 

[ericgibbs]

Hi frenchneco, U can get free samples of ICM7217 from MAXIM......

hi,
I have used the 7217 and 7227 many times, they are fine devices, BUT he has to use the 74LS192 for his project.

 

[frenchneco]

we're almost there... =) tnx for the help mr. gibbs!!! i'l just post if something comes up again...

 

[motherhugger]

whats the news about the circuit?

 

[kittyvade]

ty

tnx for evrything

 

[frenchneco]

to the newbies, read the specification sheets very well. =) that's all you need.

 

[steph_nugent]

just need a little help please

hey guys, you all seem to know what your talking about and i dont really know much, i can read a basic circuit, and solder, thats about it. i am planning to design a 3 digit display counter, with an extra bit. i need to fit something to the F9 key on a standard key board to count how many times the button is pressed. if anyone can help me, of design me a circuit, that would be soooo helpful and aprechiated.

i have an idea of how to do the F9 bit, but dont know where to add it in. could someone help please.

Thanks guys.

im steph by the way, and i live in wales, uk.

nice to meet you all.

and thanks again.

 

[ericgibbs]

hi,
When the F9 key is being pressed I'm assuming the keyboard is plugged into PC.

If so, it would be simple program for the PC to log/save the F9 operations.

 

[steph_nugent]

yes the computer will be on, how ever it is not possible to access the function which tells me how many times it has been pressed as it is in a call centre, and the computer is only functioned to do the job. I personally cant get any other information, plus this is needed as a visual aid for a project. thanks.

 

[steph_nugent]

i was think for the F9 bit, i could get a metal bit stuck on the key and a bit underneath, so when you press the button, the two bits of metal touch and that counts as one on the counter.
Told you i know nothing, lol.

 

[ericgibbs]

i was think for the F9 bit, i could get a metal bit stuck on the key and a bit underneath, so when you press the button, the two bits of metal touch and that counts as one on the counter.
Told you i know nothing, lol.

hi steph,
Look at miniature micro switches.

Something like this, it may need a debounce Res/Cap before the counter.
HONEYWELL S&C|BZ-2RW53-A2|MICROSWITCH, WIRE HINGE LEVER | Farnell UK

 

[steph_nugent]

just had a look, they dont seem to be what i am looking for. thanks though.

i basically want to make a circuit with 3 digit display, and a button for the counter, i can do the button bit i think.

 

[besoy]

PLS HELP ME TO CREATE A CIRCUIT 2MINUTES UP COUNTER UNSING (3) 7segment display, 74LS192, 74LS247 and LM555.

 

[MrDEB]

thanks a bunch!! on the heads up the ICM7217. Yesterday went to the gym and owner has an old basket ball game that has two LED readouts (need to investigate further) but the unit as no electronics, just a backboard and LED displays. Owner wants to resurrect it. The ICM7217 looks easier than using a PIC that I was contemplating.