The general purpose display with the seven LED's inside, generally used to indicate the integers e.g In Lifts to indicate the no. of floor, in mulitimeters, etc. is known as seven segment display.
Step 1: Parts
You need the following parts listed below:-
1) IC 4026 (Ic with the counter + 7 segment display interface)
2) A common Cathode 7 segment display
3) Resistor 470 ohm - 7 Resistors, 2.2k ohm-1
4) A digital Clock (That generates the periodic pulse)
Apart from this you need GCB, Female pins & Battery cap.
You can Buy these Parts from HERE !
Step 2: Circuit Diagram
Instead of directly soldering the display, I suggest you to use the female pins. So if there is problem in any LED of the display you can directly replace the display.
In-between the LED display & IC you need to connect a resistor of 470 ohm, which is not shown in the circuit diagram. In total 7 resistor for 7 LED's of display.
Apart from 2.2k ohm resistor you can also use a voltage regulator IC 7805.
Step 3: Working
IC 4026 contains a counter which increments by applying a pulse at pin no.1 . For giving the pulse you will need the digital pulse generator which is one of my previous instructable.
Apart from counter it contains a seven segment display decoder which operates the 7 LED s of the display.
As we apply the pulse the counter increments, decoder decodes accordingly & thus we observe the o/p on display.
This display counts from 0 to 9 if you want to count from 0 to 99 the make the same circuit & give the pin no 1 of the second display(that counts in tens) to pin no.4 of the first one. Like wise you can also go up to 999 or above.
Step 4: Applications
Seven Segment display can be used at any place wherever you want to display numbers.
Like :- In Elevators, In Digital meters, etc..