Friday, 2 August 2013

Positronic Brain Sim requires no MCU?

Costume Idea for Halloween

A Diamond Flashing LEDs Update I

D1 to D35 are diamond flashing LEDs. D36 and D37 are multicolor cycling LEDs. 

Just a quick update to the diamond flashing LEDs. I hacked a USB cable and attached this as the power source. I also added some two lead colour-cycling LEDs (not shown on video).

A bit of fun and very pretty. It might be good as a baby mobile or a calming mood light - it's quite relaxing and almost hypnotic. I decided to make it as a "pick-me-up project" for those long winter nights in 2012.  I'm now looking to use this idea to look like a positronic brain for halloween 2013 [positronic brain] inside a model of a human head.

The video speaks for itself. A very simple circuit with no MCU - the arrangement of led's makes the flashing pattern. I think it's the slightly different power requirements of the different colours that makes the pattern work.

I reasoned that blue and green need more power before they switch on, so red goes first. The red and yellow ones are last to go off as I gradually drop the power using a variable PSU.

Slowed down the video shows that red and yellow come on first before the pattern stabilizes. I'm not sure if this explanation of the pattern is correct. Please comment if you agree or not, or have any more ideas.

The design is copyright of Craig Turner 2012, 2013. But feel free to make some PCBs for personal use and enjoy them. No PCB copies should be made for sale or any commercial use.

You can get the led's here:


  1. Thanks Ian. Glad you liked it. Some may say: well he didn't do anything but solder a few leds, but in my view this hack is about thinking through the design, not adding superfluous components. However I enjoy doing those things too ! :)

  2. Great work man, it's beauty is in it's simplicity. I know what to do for next Christmas :)

    1. Thanks techraptor. Old saying: "less is more". I wanted a simple flashing array using these diamond cut LEDs which have a special quality light and come in cool colours. It reminded me of a positronic brain. The next task is to embed it in a model of a Human head. I agree you could use it for celebrations such as Christmas. Why not go large - 50 x 50 array anyone?