I get called every time someone in town needs
LED strips for some sort of
effect. A friend of mine who works with a local design-build staging company gave me a ton of leftover strips and several controllers like
this (Amazon). 3 outputs, 3 addresses, no muss, no fuss. Since 90% of what I do is community/volunteer
theatre, I make good use of the stuff gifted to me (being an engineer helps too -- in the attached photo,
LED strips frame the whiteboard and both transom windows).
Important things to think about:
1) There are common
anode strips (most common) and common
cathode strips. Controllers are one or the other. The link above is a common
anode controller which means that the
LED anodes (+ terminals) are common and the controller connects them to
ground -- so you distribute +12V to the strips and the controller handles the 0V (
ground). I can provide a diagram if you'd like (I presented this at
USITT a couple of years ago).
2) There are different kinds of strips that operate at different voltages. The most common is 12V (common
anode). They are usually referred to as "5050 LEDs" because the pixels are 5mm square. Beware of WS2812 strips, they are not simple
RGB LEDs, they require a more complicated controller because you provide them with +12V/Gnd and
send a data stream to them telling them what colors they should be. They are super fun to work with and I have a
universe of them doing St. Patrick's colors in front of my
house wirelessly via
SACN right now.
3) You can estimate your
current requirements pretty easily: each
LED chip has an R, a G & a B
LED in it -- fully illuminated, they each draw about 20mA each, or 60mA per "
pixel" -- If your stairs are 1m wide, that will be (for example) 30 LEDs x 60mA = 1.8A -- scale appropriately and remember that the 60mA happens when the LEDs are full (100%) white (255-255-255).
4) Since the
power supplies are made of Chinesium (thanks
@Jay Ashworth), I
fuse the input and output of each
power supply I use. Simple in-line cartridge fuses work fine. The
power supplies you buy on EBay or Amazon will *usually* self-current-limit so the
fuse on the output protects you against a
power supply overcurrent protection failure. NB: I've done this lots of times and never had a Mean Well
power supply fail on me but I
fuse anyway.
5) Don't mount your
power supplies on anything flammable (like wood). Find something inflammable to go between the
power supply and the plywood (because it's almost always plywood, right?). If my
power supplies are under a
riser or something, I get a
stage weight and put the
power supply on it -- keeps things cool.
6) Be careful of your
wire terminations. Use
crimp fork lugs to connect to the
power supply. And never (never ever) "tin" (as in with a soldering
iron) a twisted stranded
conductor before clamping it under a screw
terminal or
crimping it into a ring/fork lug. Solder is a weird substance and will "flow" under pressure, reducing the contact force and increasing resistance to the
point where things can get hot and cause a hazardous condition.
Crimp connections are your friend.
Good luck! I love playing with LEDs. They are full of Glowy Goodness.
--Jeff