Digital Clock Working Circuit

[caption id="attachment_383" align="aligncenter" width="655"]

Made by Ali Zain Ul Yasoob[/caption]

All resistor with 7-Segment-Display are 330 or 220 ohms.

There are different combinations available for resistors and Capacitors with 555 IC. Some of which are following for this general circuit diagram:(Pin 3 is output)

C₁	R₁	R₂	Period	Frequency	Duty Cycle
100 µF	3.3 KΩ	5.6 KΩ	1.0049 sec.	0.9952 Hz.	61.4 %
100 µF	5.1 KΩ	4.7 KΩ	1.0049 sec.	0.9952 Hz.	67.6 %
10 µF	100 KΩ	22 KΩ	0.9979 sec.	1.0021 Hz.	84.7 %
10 µF	8.2 KΩ	68 KΩ	0.9993 sec.	1.0007 Hz.	52.8 %
10 µF	33 KΩ	56 KΩ	1.0049 sec.	0.9952 Hz.	61.4 %
10 µF	51 KΩ	47 KΩ	1.0049 sec.	0.9952 Hz.	67.6 %
10 µF	120 KΩ	12 KΩ	0.9979 sec.	1.0021 Hz.	91.7 %
4.7 µF	10 KΩ	150 KΩ	1.0097 sec.	0.9904 Hz.	51.6 %
4.7 µF	4.7 KΩ	150 KΩ	0.9924 sec.	1.0076 Hz.	50.8 %
4.7 µF	5.1 KΩ	150 KΩ	0.9937 sec.	1.0063 Hz.	50.8 %
4.7 µF	5.6 KΩ	150 KΩ	0.9954 sec.	1.0047 Hz.	50.9 %
4.7 µF	6.8 KΩ	150 KΩ	0.9993 sec.	1.0007 Hz.	51.1 %
4.7 µF	8.2 KΩ	150 KΩ	1.0038 sec.	0.9962 Hz.	51.3 %
4.7 µF	68 KΩ	120 KΩ	1.0032 sec.	0.9968 Hz.	61 %
4.7 µF	270 KΩ	18 KΩ	0.9967 sec.	1.0033 Hz.	94.1 %
2.2 µF	1 KΩ	330 KΩ	1.0078 sec.	0.9923 Hz.	50.1 %
2.2 µF	220 KΩ	220 KΩ	1.0062 sec.	0.9938 Hz.	66.7 %
2.2 µF	120 KΩ	270 KΩ	1.0062 sec.	0.9938 Hz.	59.1 %
1 µF	1 MΩ	220 KΩ	0.9979 sec.	1.0021 Hz.	84.7 %