My candle flicker effect
I shall try and give a little explaination of this circuit as it is one that is pretty useful as a Random Number Generator.
what is happening is that there are 2 square wave oscillators giving outputs at different rates to each other
so when both inputs of the NAND gate "accidentally" hit a logic high the output is low this in turn goes into a further NAND gate configured as a inverter ie when both the inputs are a logic low the output is a logic high.
the CD4093 is a pretty useful IC - in this one circuit we have the CD4093 configured as 2 oscillators, a NAND gate and an Inverter.
the Inverter output is then connected to a PNP transistor which switches on the LED when the logic output is low on the inverter.
using a PNP in this manner is how I included an indicator LED on my Atomic Frequency Standard as it outputs a Logic low when it locks in.
so anyway the CD4093 NAND Gate basically boils down to the following statement:
Output of a NAND Gate = 1, if any of the inputs = 0
0, if all of the inputs = 1
so anyway, boring crap aside - this little project emulates the flicker of a candle, it works best in the dark of course. As you will notice there is a second LED output, this is basically just a dimly lit LED I added to because a real candle doesn't turn on and off when it flickers, so if you hot glue them together then you get a more realistic flicker.
Today i was playing with 2 of these to create a more realistic 'random' warble and somehow ended up accidentally creating a synth.
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ReplyDeleteHey Paul, I finished putting this one together to put into a Jack-o-Lantern but I am only getting constantly lit LEDs. I'm using a 9v battery and a 78L05 regulator if that matters. Any help would be appreciated.
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