Welcome - Please Read

Welcome. I wanted to provide stripboard layouts I've made to help people new to electronics and even the more experienced get into different aspects of electronics.

I verify the layouts before I post them.

My Facebook Group: www.facebook.com/StripboardLayouts - Please Add For Updates!
My Twitter Thing: @InSonicBloom

Wednesday, 20 June 2012

Candle Flicker Stripboard Veroboard Layout

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.


  1. Today i was playing with 2 of these to create a more realistic 'random' warble and somehow ended up accidentally creating a synth.

  2. This comment has been removed by the author.

  3. Hey 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.