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An easy to make, cheap and simple LED-blinky circuit with CMOS 74C14

Picture of An easy to make, cheap and simple LED-blinky circuit with CMOS 74C14
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Sometimes you need simply some blinky LEDs, for chrismas decoration, blinky artworks or just to have fun with blink blink blink. I'll show you how to make a cheap and simple circuit with up to 6 blinking LEDs.

Note: This is my first instuctable and i'm not a native english speaker - so please excuse my mistakes.


Step 1: Parts you need

Picture of Parts you need
So you need some cheap electronic parts, here we go:

- 1 CMOS 74C14 - its a small and really cheap microchip, we use it to create oscillators to make our  LEDs blink
-  some jumper wires
- a breadboard to stick the parts on it
- a 9V block battery with batteryclip
for further experiments a potentiometer around up to 1 M

for every LED-Circuit (you can add up to 6 to one chip) we need
- an LED ;-)
- a capacitor (around 4,7 µF, you may vary the value to get different blink frequencies)
- a resistor 100k-200k
- a resistor to limit the led current, around 1-3k

 
mathews5 years ago
Good little circuit. If you wanted to expand it, you could replace the LED with a transistor, and use that to source a few more LEDs (which could be placed in amongst other sets of LEDs operating at different frequencies).

You could also replace the resistor between pins 1 and 2,  with a pair of resistor and diodes in series. You can use this to adjust the mark/space ratio of the oscillation.

          R1      Diode
   |---===----|<|----|
--|                          |-----
   |---===----|<|----|
          R2      Diode

Combining these two will allow you to make a more random twinkling pattern for xmas lights.
Lapin15 years ago
Neat little circuit. Your link to Drawdio! does not explain the theory so well.
I personally prefer Fairchild application note: www.fairchildsemi.com/an/AN/AN-118.pdf.
Thanks for writing.

mischka (author)  Lapin15 years ago
Thanks for the link. There's a video of that japanese fountain that describes it very handy and simple. But your link of course provides more information.
lucas_m5 years ago
Great project; I've been looking for something like this for some time now... I just have one question: Can you replace the CMOS chip used with a TTL version of the 7414?
mischka (author)  lucas_m5 years ago
I think it would be possible with any CMOS Hex Schmitt Trigger Inverter chip. If you have one just try it out ;-), think you cant destroy something.