the display just blinked 8. is it correct to put inverters after the 74LS47? and why does the count starts at 8?Originally Posted by ericgibbs
Use ICM7217 from Maxim.
download the dts from www.maxim-ic.com and u will get what u wanted.....
hi,
No invertors are required with the 7447, the outputs are active low for driving Common Anode LED's.... you are using CA LED's ????
When you press the up/down switches does the counter count and the LS192 output change?
If the LS192 outputs change, does the LED display change?
Do you have an oscilloscope or a voltmeter??
If Yes, then use them to measure the output voltages of the LS192.
The LT 'lamp test' pin on the LS47 will light ALL 7segs [#8] if the BI and RB etc are connected as shown.
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/
Link to my Articles: http://www.electro-tech-online.com/a...icgibbs-55450/
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?
as i've posted earlier, we specifically need to do it with the given IC, which is 74LS192. but thanks for the suggestion.
using ICM7217 would not help us, because we don't have money to buy one. i'm from the philippines, and i'm pretty hard up on my finances since i'm only a student.same goes for my teammates.
here's the circuit.
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.
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/
Link to my Articles: http://www.electro-tech-online.com/a...icgibbs-55450/
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.
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/
Link to my Articles: http://www.electro-tech-online.com/a...icgibbs-55450/
we're almost there... =) tnx for the help mr. gibbs!!! i'l just post if something comes up again...
whats the news about the circuit?
ty
tnx for evrything
to the newbies, read the specification sheets very well. =) that's all you need.
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.
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.
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/
Link to my Articles: http://www.electro-tech-online.com/a...icgibbs-55450/
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