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Tom McCurdy
Nov17-04, 08:27 AM
We currenlty have a circuit that takes a pulse from a 555 chip and goes through two divide by ten 7490 switchs to create a binary counter that counts up to ten. We are trying to figure out how to convert this binary which we have displayed in regular leds into a 7 segment LED - (LN514rk)

any help would be great.
Averagesupernova
Nov17-04, 09:47 AM
Don't remember the number but there is a seven segment driver made specifically for this. If you cant find this, set it up using gates to get 10 separate outputs and then diode or those to drive the 7 segment display.
dduardo
Nov17-04, 11:47 AM
You'll need to convert the binary number into BCD and then use a 7447 to convert BCD to 7 segment.

The easy way to convert binary to BCD is to find a 74185 but it has been discontinued. If you can't find that chip you can always program a ROM to do the conversion.
NoTime
Nov17-04, 12:07 PM
The easy way to convert binary to BCD is to find a 74185 but it has been discontinued.
You could set up the 7490 to do a carry-reset on A(hex).
Tom McCurdy
Nov18-04, 06:45 AM
How would we set up the 7490 to do a carry-reset on A(hex)?
Tom McCurdy
Nov18-04, 06:46 AM
So the 7446 isn't the way to go on this circuit? We were debating between it and the 7447
Tom McCurdy
Nov18-04, 07:38 AM
Alright So what would I need to do if I can't find the 74185 circuit--- Right now again I have a 555 going to two 7490 integratded divide by 10 circuits--- and then I have access to 7447 and 7446 chips is there anything I can do with those to hook up to a 7 segment LED (LN514rk).
NoTime
Nov18-04, 08:32 AM
How would we set up the 7490 to do a carry-reset on A(hex)?
Use an AND gate or two. There are a few ways to wire this, depending on the specific behavior you want.

The 7447 should be ok. IIRC the 46 takes a higher output.
The two numbers are much the same. Look up the specs.
Averagesupernova
Nov18-04, 01:09 PM
BTW, is this counting 0-9 or 1-10?
GENIERE
Nov18-04, 06:00 PM
BTW, is this counting 0-9 or 1-10?

You can display a "10" on the 7 bit display if you mentally rotate it. A 0 to 11 sequence is possible. I learned this by laying down on the job.:biggrin:


..
NoTime
Nov18-04, 09:08 PM
BTW, is this counting 0-9 or 1-10?
Laying down on the job :rofl: :rofl: :rofl:
10 can be just about any value you can imagine.
Depends on the base you select. :biggrin:
Tom McCurdy
Nov18-04, 10:33 PM
ok i just now got acess to a 4511 integradted circuit so I am trying to figure out how to use it...