Solar panels for sensor nodes

Intro For a while now, I started replacing the dead AA(A) batteries in my sensor nodes with rechargeable NiMH ones. So, since these batteries are rechargeable, I thought, why not trying adding small solar panels for sensor nodes, where light is abundant. Node 27: outside sensor Purpose: outside temperature, humidity, light, pressure sensor. Powered by 2 x AAA 500mAh from Ikea. The solar cell is rated 3V, 125mA and is pointing vertically south and costs… Continue reading

Simple LED strip UPS – closed.

Update after 3 months The UPS is functioning as it should, and I think the solution is viable as a simple, low cost UPS where it is needed. It was a good mind and build exercise, but there are two reasons why I am not keeping it: First – realistically speaking, electricity fails way too seldom to actually use it.  Second, unless I build one of these for each room, I will always have to… Continue reading