# 7 segment circuit help

Discussion in 'General Electronics Chat' started by Xufyan, Apr 17, 2011.

1. ### Xufyan Thread Starter Member

Aug 3, 2010
114
0
i need help regarding this circuit,

I have designed this circuit but i want to connect eight 7 segments (each at the input switch) that shows 0 or 1 , how can i do this ??
I mean if first switch is off then 7 segment show '0' on its screen if it is on then it must show '1' on the screen , similarly i want to do this for each switch with different 7 segment connctd,

i just need a little logic about it because i don't know how to show 0 or 1 on 7 segment, if you can tell me how to show 0 or 1 on 7 segment i can proceed further by myself.

Thankyou-

2. ### SgtWookie Expert

Jul 17, 2007
22,194
1,761
Here is your basic 7-segment display:

Note that each of the segments has a letter assigned, clockwise from the top, "A" through "F", and "G" is the horizontal bar in the center.

So, if your output is a logic 1, then you want just segments B and C illuminated.

If your output is a logic 0, then you want segments A through F illuminated.

So, you always want segments B and C on regardless of the output, and segments A and D through F illuminated when the output is a logic 0.

There are two basic types of 7-segment displays; CA (common anode) and CC (common cathode). For your purposes, a common cathode display may be easier to work with.

Each segment requires its' own current limiting resistor. You cannot just use one resistor on the common anode or cathode, as the display will require different current levels depending upon the number of segments lit.

• ###### 7-Segment Display - Basic.png
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3. ### jt6245 Member

Feb 18, 2011
21
4
Very good and clear explanation above !!.
Usually I will check 7 segment display with DMM under diode checking range,and it lights on one segment clearly.

4. ### Xufyan Thread Starter Member

Aug 3, 2010
114
0
done...! Thanks for the help
i have designed the circuit