The finished lit frame works well, with the backlight colour correctly matching the air pressure. However, the effect was not quite as expected. First, I was expecting the colour to vary a lot, which is not really what happened. Air pressure doesn’t just go up and down every day. In fact, some values only occur…… Continue reading The birthday present 3: Done!
I had an idea. I wanted the backlight to change colour, and in an interesting way, so it occurred to me to change the colour according to the weather outside – red for bad, green for ok, blue for good. Air pressure is a good indicator of weather (low for bad, high for good) and…… Continue reading The birthday present 2: Electronics
A friend of mine gave me some art for my birthday. It was made of coloured acetate sheets sandwiched between slightly frosted plastic sheeting. I liked it, but couldn’t really just paste it to a window, it seemed to need something more. So I set to to create something. Basically, I wanted a light box…… Continue reading The birthday present 1: Frame
So, we have the frame, with its electronics, all ready. We just need to finish the shade. This piece of tubing is sold as a tumble dryer vent pipe. It’s really cheap, and just the right size. The only problem is that the ends are not cut with art in mind, they’re just chopped roughly,…… Continue reading Uplighter 5: Done!
The original purpose of this lamp was as a dawn simulator. So, at alarm time the light would very slowly fade in, like a sunrise. However, as the remote control has four buttons, I got a bit carried away assigning functions! Here’s the plan: Button “A” Press for full brightness (two white LEDs and the…… Continue reading Uplighter 4: Software
LEDs There are four 10 Watt LEDs – red, yellow and 2 x white. They are screwed to the top of the heatsink, so they point upwards. I added a tiny amount of thermal paste between the LEDs and the heatsink so that the heat is conducted across any gaps between the two. [Originally I…… Continue reading Uplighter 3: Electronics
Choosing a heatsink The lamps will each consume 10 Watts (about 1 Amp at 10 Volts). These LEDs use about 30% of the electrical energy to produce light, with the remaining 70% converted into heat. So the four lamps will create 40 x 0.7 Watts, or 28 Watts, of heat. Generally, heatsinks are rated as degrees…… Continue reading Uplighter 2: Heatsink / frame