## Introduction: 556 Time Provides Clock Input to 2 Decade Counters Which Will Drive 20 LEDS

This Instructable will show how a 556 timer will provide clock inputs to 2 decade counters .The decade counters will drive 20 LEDS .The LEDs will blink in a sequence of 10 .

## Step 1: The 556 Timer

he 556 timer is a dual version of the 555 timer. (see image)

In other words, there are two 555 timers operating separately. The two timers operate independently of each other. They use the same voltage source and ground Each Timer is provided with its own threshold, trigger, discharge, control, reset and output pins. The 556 can give clock inputs to the decade counter

### Attachments

The decade counter is the long chip named 74HC4017 It is in the first image .The IC outputs are in the second image .

A Decade counters are an unique counter .Most digital counters are binary .They count in a base 2 system of 0 or 1 . The Decade counter does too, but count up to 10 in a sequence . The outputs are Q 0-Q9. These outputs will be connected to resistors (440 ) and LEDS ,The LEDS will register the outputs and light up(LEDS) in a sequence from left to right . You can count form 1 to 10 by looking at the LEDS light up in a sequence .

## Step 3: The Parts

2 ;74HC 4017 chip

20 ;440 ohm resistors

20 LEDS

Arduino Uno

The 556 circuit

Wires
2- 0.01uf Capacitors

2- 10 uf electrolytic capacitors

1;-556 timer

4 -1 k resistors (brown, black .,red)

2- 5k resistors (green,black ,red)

2-10 k resistors (brown,black,orange)

2 -25k ; potientometers

Arduino uno and wires(same as above)

## Step 4: Conclusion

This Instructable shows how you can use a 556 timer to provide a clock input to 2 Decade counters .The decade counter will count and the 10 LEDS will blink .The potientometer in the 556 circuit will control the rate at which the LEDS blink .

This was a fun circuit to make . I made it on Tinkercad .