Do you have a tight or low budget but you need some good quality LED for your indoor plants?
A DIY LED grow light is an inexpensive and environmentally reliable way to give your plants the much-needed PPFD. It is a low-priced alternative to buying a new LED grow light. A DIY project allows you to select the light spectrum range.
The best thing about this project is that you’ve got many DIY ideas to choose from, and none of them will cost you too much. Here are our best do-it-yourself ideas you can try out today.
How to Make LED Grow Light – Step by Step Instructions
What You Need for this DIY Project
- Two starboards
- Fifty LEDs
- A pair of tweezers
- Soldering iron and solder
- A solder paste
- A reflow station
- A heatsink
- A specifically designed power supply unit for LEDs
- A multimeter with a built-in diode tester
You will need a few things for this project, including a soldering iron, soldering wire, soldering paste, thermal compound, starboards, and LEDs.
Step 1: Spreading Solder Paste on the Starboard Pads
Place starboard on a flat surface. Then warm the solder paste to room temperature. Spread your solder paste over your starboard pads. It is okay if there is bridging across the pads. When you are done with the solder paster, don’t forget to cap it and put it back in your fridge.
Step 2: Pulling Your LEDs Out of the Package
Now it is time to pull your LEDs out and get ready to populate your starboards. The LEDs usually come out messy when you pull them out of the package. You can use a pair of tweezers to turn all the LEDs upright.
Step 3: Checking the Polarity of the LEDs
Confirm the polarity of the LEDs. If you are unsure about the polarity of your LEDs, you can check the manufacturer’s product datasheet. That information is available on the manufacturer’s website. Some LEDs have a marking on top of them, which represents the polarity. You can use a multimeter to check the polarity. Most modern multimeters have a diode test installed. Just switch the multimeter dial to the diode symbol and switch the mode.
Step 4: Placing LEDs on the Starboard Pads
Once you know the polarity, you should make mental notes to avoid making any mistakes when populating your starboards. Place your LEDs on your starboard pads in the correct orientation. Standard starboard usually has twenty-five pads, which means you will be populating twenty-five LEDs on every starboard.
Step 5: Reflowing and Poking the LEDs
When you are done installing the LEDs, transfer the starboard to your reflow station. Alternatively, you can use a portable inductive cooktop with a heat transfer plate for reflowing.
But you could use an old pan on a regular stove provided you can set the temperature. The standard reflow temperature is normally about 240 degrees Celsius (460 degrees Fahrenheit). Make sure the board gets uniform heat transfer throughout. You may want to press down on the center with a pair of tweezers to expedite the reflow.
Once the solder reaches its melting point, gently poke each LED on the top. The poking will help push any excess solder from underneath the LED pads onto the surface of the starboard. Don’t poke too much, you might end up pushing the LEDs out of the pads. Move the starboard to another flat surface to cool down.
Step 6: Repeating the Above Steps with a Second Starboard
Use the above steps to populate and reflow another starboard.
Step 7: Assembling the Lighting Circuit
The next step involves assembling your lighting circuit. Before assembling your lighting circuit you should test your populated starboards with a multimeter. Use a pair of tweezers to remove any excess solder on the sides of the starboards. This makes the final product look neat.
You will need a heatsink for this step, preferably a one-inch by one-inch aluminum square tube cut to length. Drill holes into the heatsink and tape them. You will use the holes to fasten the starboards with non-conductive screws (this will help avoid short circuits). You should also consider using thermal epoxy as an alternative for fastening your starboards to the heatsink.
One thing you must ensure when you are fastening your starboards down is to make sure that they are all in the same orientation. Once you have secured your starboards in place, it is time to heat your soldering iron. Put some solder on the pads before you begin soldering the wires. The solder flows better around the wires when there is already some solder on the pads.
Solder your wires to the starboards. Make sure you always start on the positive lead and end on the negative lead. You don’t want to reverse bias any of your LEDs. Always keep a pair of tweezers nearby for bending the wires if they are too long and hold them down to the pads while you are trying to get them fastened.
In DC circuits, black is usually the color that represents the ground, while red is the color that represents the positive terminal. Use your diode tester on your multimeter to confirm that all the LEDs are working properly.
Step 8: Choosing a Power Supply
The next step involves hooking up the LEDs to a power supply. There are two things you need to take into consideration when choosing a power supply. These include the maximum drive current of the LEDs as well as their nominal operating voltage. You can easily find these two on the product’s datasheet.
Typical LEDs will have a maximum forward voltage of 3.1 volts and a maximum drive current of 1 amp. A few things you need to remember about LEDs. They are current control devices, and their current changes very quickly with slight changes in voltage. As they heat up, they tend to be less efficient, and their voltage demand decreases as the drive current remains constant.
To avoid damaging your LEDs, you need a special power supply that is uniquely engineered for LED lighting. This is usually called a constant current power supply. This special power supply will maintain a constant current over a large range of possible voltages. For this project, you have eleven LEDs in series with a maximum forward voltage of around 3.1 volts each.
The LEDs are wired in series. So, all you have to do is add all of their operating voltages to get the total voltage of the circuit. In this case, it is about 34.1 volts. You will be driving all your LEDs at 700 milliamps, which is less than their maximum drive current.
Step 9: Hooking Up the Power Supply
Hook up the power supply. Take a standard wall plug and carefully strip off the jacketing to expose the wires. You can use a soldering iron and some solder to cover the ends of the wires. When working alternating current, you don’t have to concern yourself with polarity because the current is alternating any given AC terminal. But be careful not to accidentally connect the earth ground to one of the terminals. This will trip the breaker in your home.
Step 10: Finishing Up the Setup
Finally, be careful to connect your DC lines to your LED circuit and the right orientation. Negative to negative and positive to positive. Don’t plug the supply into your wall socket until you have checked that your AC lines are connected properly. Once everything is hooked up and secured, you can try plugging in your supply. The LEDs should be working properly.