Thursday, 18 May 2017

Lighting your garden with LED lights and the sun: a DIY project, part 2.

Some time ago I wrote a short article on a small circuit I made to power on and off my garden lights using only a handful of components and some patience. Since then, however, I’ve dug deeper and found out some other good solutions to the problem.

A quick recap of the problem: At dusk and dawn I’d like my garden lights (powered by 12V DC batteries) to switch themselves on and off without me doing anything: a first step towards total automation ;)

Image 2

My first try at accomplishing this task was using a simple BJT with a voltage divider specifically design to allow a certain bias current when it gets dark. See here for more information on this first raw trial.

Tuesday, 2 May 2017

Current sink: one of my first experiences with Eagle

I’ve learnt a few things the hard way while messing around with electronic circuits, here is a basic summary: