4011 Dual Led flasher

 

This simple circuit uses NAND Gates to alternately flash two led’s. The two 47uF capacitors determine the flash frequency. It is a good idea to use a decoupling capacitor across the power supply. I made this circuit using the components shown and it worked fine. The IC that I used is the 4011 Quad
2-input NAND Gate.
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Source:http://www.geocities.com/electronics3456/4011.html