Fencing

Bit of fun...

We usually put up some Christmas lights on the house - some fairy lights on the metal fencing at the front, but a pain as means a cable out of a window. They are usually just normal fairy lights.

But with my new found expertise in WS2812 style LED strips, and my controllers, I decided to do better.

11m of wooden fence at the front of the house on the road. So let's do this properly. The key point is I have outside power at the end of the fence for the hot tub. So I was able to install, under cover, a 20A 5V power supply.

I then got 4 strings of fairy light style water proof 5V WS2812 LEDs.

I drilled nearly 200 holes, carefully measuring each to be level and evenly spaced. That is surprisingly hard work, LOL. James followed me poking LEDs through the holes. We were both expecting to fall off the damn wall, and James's main concern is I would fall off whilst he was not videoing!

But it is not quite so simple. Just in case you don't know, there are two common issues with LED strips.

Current limit

One issue is max current draw can be too much for power supply. To test you can either work it out, or, simply set all LEDs full white. 200 LEDs is too much for a typical small 5V USB charger plug. Hence the 20A 5V supply.

I actually also did 663 (11m) RGBW LEDs on nice 45 degree extruded trunking with diffusers for the hot tub as well, from same supply. Now that used a lot of current - just one 5m strip is too much for a USB 5V charger when white.

Voltage drop

This is slightly harder to solve. Along the strip the current draw means voltage drops as you go along. Different LEDs need different voltages. First you lose some blue making it yellow, and then some green, making red/pink. And even before that, when white still, you lose some brightness.

So with this 50 LED strip - one strip works. Two strips work but losing brightness at end. Three strips means going distinctly yellow at the end. I wanted four strips!

The solution

The solution is power feed in - the strips even have extra tails for power as well as the three wires for power and data. You feed in extra power at each strip end, so for my 4 strips I feed in at 5 points.

But how do you feed in power? In some cases you could simply power your longer strip at both ends and not have enough drop to the middle to notice. But I don't have power at the other end.

But actually it is possible to feed in even with just power from one end. The reason is the resistance of the wires, these are classic Chinesium™thin wire. If you actually have some thick good quality copper wire you can run and extra power lead the whole length and feed in at each strip end. This is what is in the WAGO boxes in the image.

Merry New year!

P.S. my son sells the controllers and stuff, https://hiwtsi.uk/