Convert Leds to 7 Segment Display - Electronic Circuits Projects Diagrams Free

Almazick · 12th August 2003, 11:59 PM

I would like to convert 6 leds to 7 segment display. What is the best way to do it? The way it works right now that LED’s lit up in a continuous style (for example: 1st will light up the 1st LED, 2nd will light up the 1st and 2nd LED, 3rd will light up the 1st 2nd and 3rd LED’s, etc. etc) I got 7 negative inputs and 1 positive signal as you can see from the picture that every led get grounded to lit up.

**kinjalgp** · 13th August 2003, 06:46 AM

How can you construct 7-segment display using 6 LEDs?
Please be more clear.

Almazick · 13th August 2003, 07:37 AM

I want to replace 6 Leds with 7 Segment display so it will display number from 1-6 instead of leds to lit up

bogdanfirst · 13th August 2003, 09:00 AM

simple solution: use a 8 to 3 priority encoder and then a converter from 4 bits to 7 segment display. the priority encoder must be active low.
i'll look for some IC's for this.

**kinjalgp** · 13th August 2003, 01:36 PM

CD4532 is a 8:3 priority encoder chip and 4511 is a BCD to 7-segment display driver.

Sebi · 13th August 2003, 01:50 PM

Or You can use diode array... and don't forget the serial resistors for segments.

**mechie** · 13th August 2003, 04:55 PM

Sebi
If input 3 is active (as I understand it) inputs 1 and 2 will also be active, so the display will show all 7 segments lit (displays '8' ).
Some priority encoding is required ?
Or is the diode matrix intended to still use the CD4532 8-to-3 encoder (and a decoder).

bogdanfirst · 13th August 2003, 05:18 PM

i think that the 8 to 3 and decoder is the only way.
the diodes would have worked better if you had only one led on for the specific number

Mosfet · 13th August 2003, 06:07 PM

His design uses several comparators.
http://www.electro-tech-online.com/v...ic.php?p=13146
With a LM3914 he could get one active (LED) output.
Are you locked in to seperate comparators?

Sebi · 13th August 2003, 06:47 PM

Mechie,

maybe with my bad english cannot understand right this sentence:
" I want to replace 6 Leds with 7 Segment display so it will display number from 1-6 instead of leds to lit up."
I think, only one input active (not two or more) and need to feed to 7segment display. In this case the diode-matrix can work.

bogdanfirst · 13th August 2003, 07:02 PM

Quote:

Originally Posted by Almazick

1st will light up the 1st LED, 2nd will light up the 1st and 2nd LED, 3rd will light up the 1st 2nd and 3rd LED’s, etc. etc)

so whatever number you have, that number of leds you have lit.
1: LED1
2: LED1 & LED2
3: LED1 & LED2 & LED3
.
.
.
.

Sebi · 13th August 2003, 07:09 PM

O.K.

......i thinking....

Sebi · 13th August 2003, 10:54 PM

Here is a possible solution, but this is only a small exercise for my brain...

Almazick · 13th August 2003, 11:54 PM

Hey Sebi! It actually looks like it might work. One more question. I get 6 negative inputs and 1 positive input to 7 segment display and as I can see from your picture that all 6 inputs are positive. Is it possible to put HEX Inverter to make it work? Thanks a lot

e · 14th August 2003, 12:49 AM

couldnt you do this...?

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13th August 2003, 06:46 AM	(permalink)
kinjalgp	How can you construct 7-segment display using 6 LEDs? Please be more clear. __________________ "There is no way to peace, peace is the way!"

13th August 2003, 07:37 AM	(permalink)
Almazick	I want to replace 6 Leds with 7 Segment display so it will display number from 1-6 instead of leds to lit up

13th August 2003, 09:00 AM	(permalink)
bogdanfirst	simple solution: use a 8 to 3 priority encoder and then a converter from 4 bits to 7 segment display. the priority encoder must be active low. i'll look for some IC's for this.

13th August 2003, 01:36 PM	(permalink)
kinjalgp	CD4532 is a 8:3 priority encoder chip and 4511 is a BCD to 7-segment display driver. __________________ "There is no way to peace, peace is the way!"

13th August 2003, 04:55 PM	(permalink)
mechie	Woops ! Sebi If input 3 is active (as I understand it) inputs 1 and 2 will also be active, so the display will show all 7 segments lit (displays '8' ). Some priority encoding is required ? Or is the diode matrix intended to still use the CD4532 8-to-3 encoder (and a decoder). __________________ I need a memory upgrade ... My head is full !

13th August 2003, 05:18 PM	(permalink)
bogdanfirst	i think that the 8 to 3 and decoder is the only way. the diodes would have worked better if you had only one led on for the specific number

13th August 2003, 06:07 PM	(permalink)
Mosfet	His design uses several comparators. http://www.electro-tech-online.com/v...ic.php?p=13146 With a LM3914 he could get one active (LED) output. Are you locked in to seperate comparators?

13th August 2003, 06:47 PM	(permalink)
Sebi	Mechie, maybe with my bad english cannot understand right this sentence: " I want to replace 6 Leds with 7 Segment display so it will display number from 1-6 instead of leds to lit up." I think, only one input active (not two or more) and need to feed to 7segment display. In this case the diode-matrix can work.

13th August 2003, 07:09 PM	(permalink)
Sebi	O.K. ......i thinking....

13th August 2003, 11:54 PM	(permalink)
Almazick	Hey Sebi! It actually looks like it might work. One more question. I get 6 negative inputs and 1 positive input to 7 segment display and as I can see from your picture that all 6 inputs are positive. Is it possible to put HEX Inverter to make it work? Thanks a lot