7 Segment Display Using 555 Timer and 4026 Decade Counter

This circuit diagram is for a seven-segment display driven by a 4026 decade counter, which receives the clock signal from a 555 timer IC. If you made the previous circuit to this, which used a push to make (PTM) switch to generate a clock pulse, then this circuit is a step forward and uses a 555 IC in astable mode to generate a slow clock pulse. If you made the previous circuit, then this is simply an addition of some more components.

If you are a GCSE student, then the 555 Astable Flashing LED article should be of interest, because I have also shown how to calculate the period. All that we are doing in this circuit is taking the output from pin 3 of the 555 IC and feeding it to the clock input of the 4026 chip. This should be very useful practice because you never know when such a circuit could come up in the exams. In addition, you are learning about two ICs at the same time!

Experiment

If your panel has a decimal point (dp) segment, then we can connect it to various places to see the output. If you connect it to the output pin 3 of the 555 timer, then it should blink in sequence to the changing numbers. However, if you connect it to the "Carry Over" pin 5 of the 4026, then it should blink once at the end of the tenth count.

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