Updated: Sep 20, 2022
Ever wonder what's really happening on a strip of LED tape? Well, grab a cup of coffee and settle in because today we are going to really zoom in on what's happening on that little strip of LED tape we all love to design with.
Our good friend John Demous at City Theatrical was kind enough to send us a sample of one of the latest products in the QolorFLEX line, which we are utilizing for our deep dive today.
LED tape has become a popular tool in Lighting Design over the past few years, and recently products like the Qolorflex HiQ tape have taken the possibilities to the next level, providing vibrant colors, warm white tones and crisp cool white light all in one great product that boasts a high color rendering capability of CRI>95.
But what does it take to pack all of that punch into a LED node that is amazingly small (less than 3/16" square) and still give you all the intensity you need?
Today, JWD is going to help you discover the answer to all those questions and more. JWD has specified, installed and designed countless projects through the years, utilizing tens of thousands of feet of LED tape, customized to fit each unique design application. Over the course of those projects we have gotten to know lots of interesting details about LED tape and had the opportunity to learn from manufacturers about how their products work.
Understanding the LED Chip
Let's take a look at the LED chip responsible for creating the illumination that comes from the tape. Above, you can see a close up view of the LED chip itself. It's soldered to the tape just like a circuit board, in fact this type of tape is sometimes referred to as "chip on board". The reel of LED tape is 5 Meters long and is made up of (50) 100mm long segments, known as cut intervals. Each 100mm segment contains 6 LED chip modules like the one shown above. Each chip module is made up of 5 sections, each responsible for a different color. In this case the chip features red, green, blue, warm white and cool white. Below we will show you what part of the chip module is responsible for each color.
Above we see the location of the RED LED in the chip.
Above we see the location of the GREEN LED in the chip. Just to the right of the RED LED.
Above we see the location of the BLUE LED in the chip. Just to the left of the RED LED.
Above we can see the locations of the WARM WHITE and COOL WHITE LEDS. Notice that they take up more surface area on the chip.
Working with LED Tape
So now you know a bit more about where the light comes from, now let's look at some of the construction details you need to know in order to understand how to work with it effectively.
Above is a close up view of the cutting line on the LED tape.
We mentioned before that the the tape is made up of 100mm segments. LED tape is designed to be cuttable in the field at selected intervals, in this case they are 100mm long and designated by the dashed line. Cutting the LED tape along this line will shorten it to the length required by the design. It's important to know that the tape can be cut ONLY on the designated cut lines, cutting between the lines won't work and will ruin the cut section of tape. Notice that the cut line crosses six copper pads. This allows room to solder on wire to the tape after it is cut.
Wait - there are 5 colors. Why are there 6 solder pads and 6 wires? What's this +24V all about?
Here's the reason for that sixth wire, called the V+. V+ is shorthand for voltage positive, in this case our QolorFLEX HiQ 5-in-1 LED tape runs on 24 volts DC. A 24 volt DC system is comprised of 2 wires, positive and negative, just like a battery. And just like a battery, or any DC system, power flows from the positive to the negative to make a complete circuit. I'll leave the details beyond that to a future post.
So, if the tape is 24 volts DC it needs a positive and a negative, right? Where is the V-?
This is where LED tape has some genius engineering. The 24V+ supplies the positive to the entire strip of LED tape, but the V- is broken up into a separate wire per color . In the image above, the black wire supplies V+, but each of the other wires completes the circuit (V-) of only one color, this is what makes the tape controllable via a remote dimmer and allows you to mix and match colors to your hearts desire.
I'd like to take a moment to salute City Theatrical on their choice of wire color for this product. Black is V+, the red, green and blue wires are for red, green and blue, yellow is warm white and white is cool white. This makes perfect sense and I wish every tape was like this. Hookup is a breeze when the wire colors make sense, bravo!
Dimming LED Tape
LED tape is designed to be used with LED Dimmers. In our industry these dimmers are primarily the type that are controlled via DMX control protocol. For our deep dive we utilized City Theatricals QolorFLEX 5x8A dimmer - 5809. If you are wondering, the 5x8A indicates the dimmer has 5 control channels, each capable of 8 amps.
Above you can see the QolorFLEX dimmer. Notice that it has an XLR connector at the top to supply DMX, an LED readout on the front with buttons to easily set the DMX address and change other settings, and a set of screw terminals on the right for input voltage and output to the LED tape.
In the image above you can see that V+ and V- are supplied to the dimmer via the red/black wires on the bottom right of the picture. Once the dimmer has power, in this case 24V (although it can also be 12V if that is what your tape requires) the dimmer uses the DMX signal to determine which of the 5 outputs (RGB Ww Cw) get power, and how much power they receive, thus dimming them in any combination you like. The V+ going to the tape is always on, that never gets dimmed by the dimmer.
Above is a close up of the wires going into the dimmer. From left to right: 24V-, 24V+ (both input voltage from the power supply) then the smaller wires go to the tape: V+, red, green, blue, warm white, cool white.
Now you know some of the basics to help you understand LED tape better, but we have only scratched the surface of the technical knowledge needed to properly design and install systems that use these products. JWD has over 20 years of experience designing with light and along the way we have developed a deep knowledge of how these products work and how to use them properly to get outstanding results. We hope that this article has helped you better understand how LED tape works, and that if you have a project that needs professional design you will consult with an expert like JWD.
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