• GCSE:
• 4017
• Sequence
• Chaser
• Mini Project
• Controller
• Traffic Lights
•  

GCSE

Example Application - LED Sequence

• This 4017 chip is clocked using a 555 Astable running at 2.5 Hz.
• It will count repeatedly from 0 to 9.
• When the count is 1, the first LED turns on.
• When the count is 3, the second LED turns on.
• When the count is 5, the third LED turns on.
• While the chip counts from 6 to 9, no LEDs come on.
• When the count is 0, 2, or 4, no LEDs come on.

Electronic Die

• The circuit above could be modified to make an electronic die.
• Six LEDs would be needed, connected to the outputs 0 to 5.
• Output 6 would be connected to the master reset pin so the chip would never count from 6 to 9.
• The astable should run so fast that the LEDs flash in a blur.
• To throw the die, the counter is stopped by switching a switch.
• As this happens at an unpredictable time, the dice throw will be random.
• LED 1 is connected to the chip output 0.
• LED 2 is connected to the chip output 1.
• LED 3 is connected to the chip output 2.
• LED 4 is connected to the chip output 3.
• LED 5 is connected to the chip output 4.
• LED 6 is connected to the chip output 5.

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