CD 4001 is a quad, 2 input NOR gate IC made by Fairchild Semiconductors.  It is a monolithic CMOS transistor based IC having efficient source and sink [[wysiwyg_imageupload::]]capabilities. Circuits that use this IC can be easily operated using battery as CD4001 is a low power consumption IC. A 14 pin DIP package, this IC can work at temperatures upto 1250. The circuit in this project is built around a commonly used CD4001 IC and few more discrete components. The circuit described can be used to decorate your Christmas tree with colorful lights. The blinking of LED’s will create a festive appearance which will enhance the Christmas mood.

CD4001 is the most commonly used Complementary Metal Oxide Semiconductor (CMOS) chip.  It comes in a 14 pin Dual Inline Package (DIP). It has small [[wysiwyg_imageupload::]]notch on one side which is identified as pin 1.It consists of 4 independent NOR gate in a single chip. Each gate has 2 inputs and 1 output. Working voltage range of IC is from 5V to 15V. It can deliver approx.10mA at 12V but this can be reduced as power supply voltage reduces. IC consists of 14 pin where pin numbers 7 and 14 are connected to battery or DC power supply. Negative is connected to pin 7 and pin 14 is connected to power supply. As we know it has four gates we call it NI1, NI2, NI3, NI4. In first gate NI1 pin 1 and 2 are for inputs and pin 3 is for output.