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Member
nilly
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How to connect using 7447N to 7 segment display?

As i'm new to multisim,i have no idea how to make the circuit works.Can anyone help me troubleshoot ?

Member
Tom__Sedlack
Posts: 139

Re: How to connect using 7447N to 7 segment display?

When using digital parts (the 7447), you need to use a digital ground (DGND).  Also, never assume the logic state of open pins.  Pull them high or ground them as required.  It's good engineering practice.

Member
nilly
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Re: How to connect using 7447N to 7 segment display?

Hey thanks for the fixed but can i ask is it possible to add in NAND gate into it? Cause i need to display digit 0 to 5 with the least number of NAND gate.


"Using multisim,design  an octal-to-7-segment common cathode decoderfor digits 0 to 5 using the least possible number of NAND gates only. You are to assume that only octal digits 0 to 5 are applied to the inputs of the decoder, i.e. combinations for digits 6 and 7 arenever applied."

 

Please help i'm stuck with this assignment  

Member
nilly
Posts: 5
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Re: How to connect using 7447N to 7 segment display?

Hey thanks for the fixed but can i ask is it possible to add in NAND gate into it? Cause i need to display digit 0 to 5 with the least number of NAND gate.


"Using multisim,design  an octal-to-7-segment common cathode decoderfor digits 0 to 5 using the least possible number of NAND gates only. You are to assume that only octal digits 0 to 5 are applied to the inputs of the decoder, i.e. combinations for digits 6 and 7 arenever applied."

 

Please help i'm stuck with this assignment  

Member
Tom__Sedlack
Posts: 139
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Re: How to connect using 7447N to 7 segment display?

You can add as many NAND gates as you want, however, I have no intention on doing your homework for you.  Create your K-map, minimize it, then wire it.  Check with your Professor ot T.A. to see if the can point you in the right direction.

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sam6113
Posts: 3
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Re: How to connect using 7447N to 7 segment display?

i m making circuit of stopwatch, can any one plz help me out, this circuit is correct but neither of seven segmnt display is working....:smileysad:

Member
Tom__Sedlack
Posts: 139

Re: How to connect using 7447N to 7 segment display?

Where to start.....

 

74LS48 are designed to drive common cathode (CK) displays. Change the 74LS48 to 74LS47 (Common Anode Drivers) or change the display to common cathode.

 

Read the other posts in this thread on how to wire LT, RBI, and BI/RBO. NEVER leave an input un-terminated.

 

Speaking of un-terminated, you need to connect the CK/CA pin on the displays to ground/VCC.  

 

In the simulation world, you can get by without the current limiting resistors on the LED inputs. In the real world, 100 ohms or so on segments a through g should be added.  Get in the habit now.

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sam6113
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Re: How to connect using 7447N to 7 segment display?

in this case of above attchd circuit, where to connct RBI,RBO,..... pins?  can u attach a edited/reformd circuit which works as a stopwatch?

Member
sam6113
Posts: 3
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Re: How to connect using 7447N to 7 segment display?

in this case of above attchd circuit, where to connct RBI,RBO,..... pins?  can u attach an edited/reformd circuit which works as a stopwatch?

Member
Tom__Sedlack
Posts: 139
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Re: How to connect using 7447N to 7 segment display?

The second post in this thread shows you how to connect them. You can also search for "7447" in this forum and find more examples.