# LED Christmas Lights Circuit

Have your already set up a Christmas tree in your house and decorated it with traditional lights? Build a couple of these led lights to enhance the Christmas mood. The coloured LEDs blink in a seemingly random sequence and rate and create a festive appearance that is perfect for these special holiday.

The led Christmas lights circuit has a very simple design. It is based on a type 4060 digital counter(IC1). This IC has a built-in oscillator with a frequency set by the combination of resistor R1 and capacitor C1. The oscillator frequency is approximately 5 kHz with the component values shown here. The oscillator signal is divided by various factors by the internal digital circuitry of the IC.

The division factors are designated by ‘CT’ in the IC drawing symbol. For instance, the signal on the CT3 output (pin 7) is a square wave with a frequency equal to 5 kHz divided by 23, which mean (5 kHz : 8) = 625 Hz.

The oscillator signal is divided by 24 (16) on the CT4 output, by 25 (32) on the CT5 output, and so on. The signals on each of the outputs thus change at different rates. Eleven LEDs are connected in three groups between six of the counter outputs, with the result that the group of LEDs flash in an apparently random pattern.

## LED Christmas Lights Decoration Circuit Schematic

To assemble the led Christmas lights circuit, first solder the IC socket (mind the polarity), the two resistors, the capacitor, and the battery clip to the triangular circuit board. Then fit the eleven LEDs. Pay attention to the polarity of the leads: the short lead is the cathode lead. After a final inspection, you can connect a 9-V battery to your Christmas LED decoration>. It should produce a festive blinking pattern!

## Related Tutorials

• John

Is it possible to have a circuit with more LED’s? I was thinking in the region of 80-100.

• spa2036

Maybe I missed something. According to the datasheet of the CD4060 the frequency is calculated as follows: 1 / (2.2 * R1 * C1) which means 1/(2.2*10000*0.000000001) = 1 / .0000022 = 45454.54 Hz ( 45.5kHz). Maybe there is a typo in the schematic or I did not make the right calculation. It puzzles me…..

• Elcid534

And on further inspection pin 8 IS ground, so lol, it’s pin 12, which is the reset line that’s being held to ground, which is actually a good idea, convention and all

• Elcid534

On inspection of the data sheet curtesy of Texas Instruments, pin 8 is unconnected, and so really what’s he has drawn is connecting it to ground, which is just some convention where you don’t leave pins floating, otherwise,circut operation “should” remain unaffected, else I missed the part about pin 8 in the data sheet
-elcid534

• ctwistedpair

On the left side of the ic, pin 12 is tied to pin 8 below and what above? I cant tell if it’s a one or a typo… On the right side of the ic, there are lines like 7,8 and 9 that have a number next to them. Does this mean that they are tied to those pins?
You can tell I’m new at this. Thank you for your help and thanks for posting this.

• Johnny

Plz sir can hi used IN4148 for high speed switch..helpp

• Christmas Lighting in Orlando

Driving around and seeing houses lit-up with Christmas Lights always brings me into holiday spirits.

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