June 2001 Project : Count To Ten With Lights
Before we can present this months project, we will need to review the some information about the 4017 IC Chip. The actual chip that we will be using is the CD4017. It is CMOS chip, therefore it can operate on a supply voltage of 5 to 16 volts dc on pin 16. The chip is basically a decade counter or a dived by 10 counter. It has 10 outputs that can supply up to 10ma. each. The outputs will turn on one after an another with each clock pulse received on pin 14. To operate the chip the supply voltage must be connected to pin 16 and pin 8. The clock enable pin 13 must be connected to ground and the reset pin 15 must be connected to ground. A clock pulse can then be supplied to pin 14. On every clock pulse the outputs will turn on positive from Output # 0 to Output # 9 and then start over again.
The circuit presented this month is a basic configuration of the very versatile 4017 IC Chip. In the most common use of the IC, it will turn on 10 separate outputs sequentially. Typically, the circuit is used to turn on a LED for certain time cycle. In the circuit shown the VR can be adjusted so that the clock output of the NAND gate will be 1 second. With this clock at 1 second intervals, the 4017 chip will turn on output # 0 to be high which will light and LED. When clock pulse 2 is received a second later, output #1 will go high which will turn on LED2. This process will continue until all 10 outputs have gone on and then it will start all over again until you turn the power off. When building this circuit you should tie the left over pins of the other NAND gates in the CD4093 to ground. Therefore, pins 5,6,8,9, 12 and 13 should be connected to ground.
