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I am, as you may know, a sucker for watches that use older display technologies (see also Nixie tubes). For example, this cool watch by freelance engineer..
There is really not much to write about. I saw the nice freeform Annoy-o-tron 2000 and got infected. Grabbed one 555 timer as I saw a nice solar engine circuit with 555 timer chip on Instructables, some solid core copper wire and started bending wire and soldering everything together. Not much a plan, just real time design :-D Here some photos of my creation: All components are soldered together based on the 555 chip atteched to the main frame. The lower ring is negative and the upper ring...
BATTERY MONITOR A very simple battery monitor can be made with a dual-colour LED and a few surrounding components. The LED produces orange when the red and green LEDs are illuminated. The following circuit turns on the red LED below 10.5v The orange LED illuminates between 10.5v and 11.6v. The green LED illuminates above 11.6v By Collin Mitchell - 30 LED Project.