Blog – LED transformers – Power Supplies for LED Lighting

Beginner’s guide to powering up and controlling the brightness of your LED lighting products

The terms LED transformers and power supplies for LED lighting are used interchangeably. This is not to be confused with constant current LED drivers which are very different and will be discussed at another time. Most of the LED products we offer to operate at low voltage and are designed to be powered by an AC to DC transformer with a regulated voltage output of 12 or 24 VDC. That simply means that you are able to convert 120-240VAC household voltage, and in some cases, up to 277VAC, to a stable low voltage suitable to operate your LED strips and fixtures. So how do you decide which LED transformers you need? It’s relatively simple. Let’s take our 30 LED per meter flexible LED strip for an example. The product page for flexible LED strip has all the information you need to determine the proper power supplies. First, you will see that this product operates at 12VC, so obviously, you will want a LED transformer with a 12VDC output. Next, you will need to know what your total power consumption will be. Flexible LED strip is sold in lengths as small as 3 feet and as long as 5 meters which are approximately 16 feet. Power consumption is as follows in Milliamps: o 3′ – 600mA o 6′ – 1200mA or 1.2 Amps o 9′ – 1800mA or 1.8 Amps o 12′ – 2400mA or 2.4 Amps o 16′ – 3000mA or 3 Amps Now, let’s have a look at our LED transformers page. The power supplies for LED lighting are listed on this page in order of the smallest capacity to the largest capacity. It is important to note that LED transformers should be de-rated. That means you do not want to push a transformer to its maximum capacity. For safety and durability sake, utilise only 80% of the transformer’s capacity. o TX1-A is a 1 Amp transformer with 800mA maximum load. o TX5-A is a 5 Amp transformer with 4000mA (4 Amp) maximum load. o A-PS100 is an 8.5 Amp transformer with a 6800mA (6.8 Amp) maximum load. So, if you were considering the purchase of 3 feet of flexible LED strip and do not intend to add more strip later, you can safely use our smallest transformer, TX-1A. You would need to go up to a TX-5A if you were going to operate up to 1 full reel. And if you were going to run two reels, you’d need to step up to the A-PS100. There are larger power supplies available for larger projects up to 20 Amps capacity. If you need something even larger, we can help you with that. And, it doesn’t hurt to use a larger transformer. So if you think you may add a more flexible strip, later on, choose a larger power supply. The Transformers listed above are all for use in dry locations only. Further down the page, you’ll see that we have waterproof power supplies for outdoor use such as landscape lighting or billboard lighting. Dimming 12 or 24 VDC LED lights follows the same principle. There are two ways to dim LED products: with dimmable transformers for LEDs or with low voltage dimmers for LEDS. Dimmable transformers for LEDs are found at the bottom of the Transformers page. These allow you to use a standard household 120VAC wall dimmer on the line voltage side. These also come in different capacities and do not need to be de-rated: o 60W 12VDC 4 Amps o 150W 12VDC 10 Amps o 200W 12VDC 16.7 Amps o 300W 12VDC; 25 Amps So if you wanted to dim 2 full reels, you’d have a power consumption of 6 Amps and can use the 150W 12VDC dimmable transformer. The second method is to use low voltage dimmers for LEDs. In these installations, the dimmer will go in between the transformer (12VDC) output and the product input. The simplest of these are the Zane control products. You’ll see that the maximum load on the dimmer with wall plate is 4 Amps. These do not need to be de-rated. There is also a mini-dimmer with a capacity of 8 Amps. These are particularly useful when you are working with a control box or control panel. There are also low voltage remote control dimming devices. At TheLEDLight.com, we’re all about customer service. If you need help determining the proper power supplies and dimmers for your LED products, use our ‘call me back’ form or give us a call at 775-841-4490. If you haven’t purchased the particular LED product you need to control from us, please be sure you know what the operating voltage and power consumption of your product are. Flexible LED strip, for example, does come in both 12 and 24VDC and some of it even operates at line voltage. It can be produced with a variety of different LEDs in different densities, and all of that is relative to selecting the proper controls. Thank you as always for coming to TheLEDLight.com. We look forward to hearing from you.

By: Mary Wecker