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Multiplexing Seven Segment Display

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Here is the link to the IC
www.fairchildsemi.com/ds/74/74F579.pdf
also see this
**broken link removed**

If I could Utilize these IC as two BCD counter My problem would be solved!

hi,
I would think that trying convert the 8 bit binary counter to 2*BCD is not feasible.
There are more 'elegant' ways to get the mux method you require.
 
Since I can't find the tri-state buffers, I am trying to make my own!
Will using A bc557 NPN transistor with its base as the enable pin, work? Look at this
**broken link removed**

(sorry for this awkward drawing again. I am struggling to learn the PCB drawing program, eric gave me)
 
Since I can't find the tri-state buffers, I am trying to make my own!
Will using A bc557 NPN transistor with its base as the enable pin, work? Look at this

i suggested to use 4016, or 4066 IC as a switching multiplexer, did you check it in your local store??
 
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i suggested to use 4016, or 4066 IC as a switching multiplexer, did you check it in your local store??

I did. But the answer is negative! Actually this may sound so ridiculous to you guys, the electronic Shops here only sell ICs that are frequently used. Its difficult like hell to find ICs that are a bit off the general line.

Noone answered my question, Wouldn't using the transistor as the switch do the job?, I have lots of transistors waiting!!
 
Noone answered my question, Wouldn't using the transistor as the switch do the job?, I have lots of transistors waiting!!

hi tc,
If you have to use transistors, you could consider 'negative' logic connections.

ie: drive the bases of the transistors with say a 330R from the counter output, use only one resistor from the collectors of transistors on a common signal line. [OR'd lines]

This means that when an counter pin is high it will pull down the line down.
To each transistor base you would need say a diode which can be pulled low to inhibit that transistor,

Its an awful way to do it.:)
 
Never-mind but it would be awesome instead, just imagine of 24 transistors staying up in a line, just to make the digital clock a success. My friends would envy that beauty! lol !
I didn't quite got why would you think I would need a diode to the base, wouldn't a 330R resistor suffice?
 
the ICs i sugested are used in some TV sets too for switching Audio & vedio for input selection. there are some other ICs for similar application, let me have a look
 
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