# voltage level with 7 segment

Discussion in 'The Projects Forum' started by sangebaba, Dec 24, 2012.

1. ### sangebaba Thread Starter New Member

Dec 24, 2012
1
0
hi,,,,
i want to use 7 segment in voltage level indicator instead of LEDs so what should i have to do with the circuit(circuit is given below)
i just want to show
0 for voltage < 10.5
1 for voltage > 10.5
2 for voltage > 11.5
3 for voltage > 12.5
4 for voltage > 13.5
and i want to use 0-24 volt DC supply instead of 12v lead battery so what would i do??

File size:
101.2 KB
Views:
47
2. ### spinnaker AAC Fanatic!

Oct 29, 2009
5,065
1,176
With all logic / opamp chips that is going to be a challenge with more components than you have already. Consider looking at a micro controller like something out of the PIC line of chips. One mcu a couple of resistors and capacitors is really all you need.

Then you could display any voltage you wanted over a wide range of voltages.

You could add a couple of chips for BCD to seven segment to make it easier on yourself as far as coding and wiring but one chip (the mcu) is areally all that you need as long as you want to tackle the complexity of charlieplexing.

sangebaba likes this.
3. ### absf Senior Member

Dec 29, 2010
1,493
374
Have you done the truth tables as attached. After making the truth table, you can make a simple logic circuit using NAND gates like 4011 and a BCD to 7seg LED chip 4511 or 4543 to display your result on CC LED.

And yes, the simplest solution is like what spinnaker says.....use a pic or avr. What about a PIC16F88.

Allen

• ###### SANGEBABA.PNG
File size:
3.4 KB
Views:
30
sangebaba likes this.
4. ### ScottWang Moderator

Aug 23, 2012
4,925
777
Op Amp voltage detector → Voltage limit → 74HC147(Or 74HC148) → CD4511 → 7 Segment LED (0~9)

Last edited: Dec 25, 2012
sangebaba likes this.