Joined: Jan 31, 2010 Posts: 302 Location: Denver, CO
Posted: Mon Jan 14, 2013 3:10 pm Post subject: A Complete Idiot's guide to make an LED lighting unit
As always I am writing this for people who have no prior experience with LEDs, electrical and electronics works just like I never had before I did this. I will be posting a lot of pictures here and going into a lot of detail about making connections, wiring etc. So the people who know how these things are done may find it boring and unnecessary, but please bear with me.. it’s for the newbies.
In order to understand LEDs and what kind best serves your needs go to my previous post – An Idiot's guide to understand LEDs
It contains all the theoretical aspects of LEDs and in very simple language. Once you have a good understanding of what you need, read this post.
Before starting this thread I would like to thank Milad, who helped me a lot throughout this tedious process. He is an awesome guy.
I ordered the following things for Lighting from LEDGroupBuy.com:
water proof cable connectors
two pin plugs
extra wire (in case needed)
make sure to make a rough sketch of how you would assemble your LEDs on the Heat sink. It is very helpful to refer to it when making the circuit. Without it there will definitely be a lot of confusion and chaos. A blueprint of this is available on LEDgroupBuy.com- Blueprint And here is mine for reference –
People in India might be a little disappointed because it’s not available there. But I am sure you can speak to Milad if you really want it and can work something out. Check out "Contact Us" page of www.ledgroupbuy.com
1. To start, test each of the LEDs if they are working. For testing I ordered a Multi-meter from LEDGroupBuy.com. Connect the red and black wires (with pins on the end) to the multi-meter body as shown below. Now turn the knob to point to (diode) symbol. Gently touch Red wire pin to positive and black-wire pin to negative of the LED you are testing as shown below. If there are no defects on the LED, it should light up. In case it doesn’t light up, check the connections to the multi-meter again and whether its knob points to symbol.
An alternative way of testing (without the multi-meter) is to use two AA size batteries and connect the positive of the batteries to positive plate and negative of the batteries to negative plate of the LEDs.
2. You must have received a no. of nuts, bolts and washers. Join them in as shown in the picture. Now place them into the grooves of the heat sink as shown below. For every LED you will require 2 sets of nuts, bolts and washers. Arrange these bolts in the same way as you have made in your blue print. This gives you a rough
idea of the positioning of your LEDs.
The Nuts and Bolts-
You have to put them together in this way-
They send many extra pieces-
Then put them into the groves of MakersLED heat sink-
3. Pick up one LED and put a tiny bit of thermal grease on its back. Gently put the LED on its respective position on the heat sink and press it. Once in place, tighten the nut-bolt pair on the grooves. This holds the LED in its position. Do this step for all LEDs. Now all your LEDs are fixed on the heat sink on their respective
positions. Make sure that you have placed all the LEDs in a way that you are able to connect all of them in series (- of one LED is connected to + of the other -- - + - + - + - + - + ….- +)
Dont worry about the mess (I'm sure it the grease will mess up the heat sink). It can be wiped by a tissue later.
4. Now to wire all LEDs first pre-tin the connecting points of each of the LEDs. Pre-tinning is nothing but putting a small layer of soldering material on your connections.
• Heat your soldering iron. When it’s hot gently bring it in contact with one end of the soldering wire. The soldering wire immediately melts leaving a drop on the hot tip of the iron. Gently place this drop on the small connecting plates of the LED you are connecting. Let it cool. It takes about 3-5 seconds to cool off. Do this for all the LEDs.
This step makes it faster to connect wires to all twenty LEDs.
5. Now, take the wire and cut it into pieces of appropriate length. If you like you may use red wires for positive and blue wires for negative. The wire should not be too long, it should not sag or touch other LEDs (because otherwise it will be damaged due to the heat of that LED). Scrap off insulation from both ends of all of these wires (about 2-3mm). Once you have cut all the pieces and scraped off their ends start soldering them.
• For this bring the hot tip of the soldering iron in contact with the pre-tinned connection plate of an LED very briefly. This will melt the shiny tin layer. As soon as this happens hold the wire with a pair of tweezers and gently push its end into the melted metal and let it cool. Once cool, it holds the wire firmly. As you make connections for each LED you can test them with the multi-meter or a battery as mentioned earlier. Repeat for all LEDs.
6. In my case, I have also used DIM4 circuit which produces the day-night dimming effect. I have made power connections in the following manner. You may connect them in any other way you like.
• Out of 20 LEDs, 15 are connected to an LED Driver (I have used Inventronics 40W driver – 700 mA) An LED driver converts AC to DC on which all LEDs run.
The driver has 3 sets of connections – AC in (2wires - black and white), DC out (2 wires – red+ and black-) and Dimming Controls (3 wires – green -, purple+ and yellow x).
Two wires positive+ and negative – of the dimming control on the LED driver will go to a channel of DIM4.
In case of this particular driver, purple is positive, green is negative and yellow is not used anywhere. Remember it like this – purple – P- positive; green-is mean-hence negative and yellow-is a dirty fellow- therefore not used.
•3 Royal Blue LEDs are powered by Channel 1 of DIM 4 Circuit.
•One OCW (ocean coral white) is connected to Channel 2 of DIM4
•One OCW to Channel3 of DIM4.
For people who are not using DIM4 circuit can connect all the LEDs to the LED driver and they are good to go.
7. Now place the optics you ordered. These optics are nothing but special lenses that concentrate light. I have used the ones that concentrate at a 60? angle; you may choose what every suits you. In order to stick them to your LEDs you can use a hot glue gun. I was not sure what to use so I ordered a thermal adhesive from LEDGroupBuy. If you are doing the same, you will receive two small tubes, combine a very small amount of both in equal proportions and use it to glue the optics. A word of caution – it smells terrible. This glue dries very quickly, so mix very small proportions every time. DO NOT USE SUPER GLUE. When heated, super glue produces fumes which clogs the LEDs and damages them. You can again test all LEDs here.
This is how the 'shades' look under my LED unit
8. Now you can cover your LEDs with the splash guard. This is nothing but an acrylic sheet. Place 4 Upper T-slot plugs and Plastic-end Caps on each of the sides of the heat sink. On top of the heat sink place the fan along with its circular frame and fix it with nuts and bolts. Your LED unit is ready.
9. Now, let’s talk a little bit about drivers and dimmers.
This is necessary to understand and helps you make the right connections. Dim4 has 4 channels (CH1, CH2, CH3, CH4) Two relays (R1,R2) and Power supply-in.
Each of the channels of the DIM4 is capable of lighting up to 3 LEDs and 0,1 or more drivers. Let’s consider two cases here –
• CASE I : Using DIM4 to control Drivers that are connected to LEDs:
Each channel of DIM4 can control dimming options of at least one driver. In this case DIM4 will command the Driver to dim, giving the sunrise and sunset effects. If DIM4 is connected to drivers, it will require only 500mA current.
• Case II : Using DIM4 to control LEDs directly (no LED driver):
Each channel of DIM4 can light up exactly 3 LEDs at a time. DIM4 will directly command all LEDs to give the sunrise-sunset effect. If all LEDs are connected directly to DIM4, it will require more current – (I've used 5A). Hence you will need to use – THIS
• My Case:
I have used –
i) Channel 1 for my LED Driver. This driver lights up 15 LEDs.
ii) Channel2 for OCW1 (Ocean Coral White), which is a set of 3 LEDs of color red, blue and green.
iii) Channel3 for OCW2 which again is a set of 3 LEDs – red, blue and green
iv) Channel4 for 3 Royal Blue LEDs.
• Relays: There are two relays R1 and R2 in the circuit. Relay R1 fires up as soon as Channel 1 goes live and Relay R2 fires when Channel3 goes live. Both relays give a power supply of 12V. Now these relays may be used to control your fans. I used R1 to start my fan which sits on top of theheat sink. As soon as my Channel1 goes live, it controls my LED driver connected to 15 LEDs; at the same time, relay R1 fires, turning on the fan over the heat sink to cool down the heat sink.
10. If you are using DIM4 to light up your LEDs directly, it will produce a lot of heat. In order to cool it down you will need another small fan. For my device, I placed both my LED Driver and DIM4 inside a plastic container and attached a fan on top of it by making a circular hole on top lid right under the fan blades. I made holes on sides of the plastic box from where wires can go inside as well as for air circulation.
When I was doing my final test-
11. Now make all the remaining connections – the ones to driver, DIM 4 etc. Make sure you don’t leave any loose ends. Cover all the connections with electrical connectors/insulation tapes. Do not leave the soldering iron ON unattended.
12. Install the hanging kit. And you are good to go.
[size="5"]Note-[/size] If you are one of those (well, I was) who "overthink", there are pretty fair chances that you can do this-
[SIZE="4"]DO NOT DO THAT[/SIZE]. OCW (Ocean Coral White) has already been soldered in series. You DO NOT have to connect it in the series.
[SIZE="4"]THE PROPER WAY IS THIS[/SIZE]-
Disclaimer [SIZE="4"]This post is just how I did it and my . You may have other options and ideas. I wrote it because I didn’t find any similar post to help me when I did it. If you follow this and incur any losses/damages, then I am not responsible for it. I am also not responsible for your safety around electrical items.[/SIZE]
Thank you for reading and watching It was a [color=#FF0000]Superman presentation[/color] (never mind, lol).
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