LED-based plant lighting is a valuable and very useful accessory for many hobby gardeners. Too bad that such a plant light is not exactly cheap in the trade. Depending on the size and design, this can quickly add up to several hundred euros. It becomes significantly cheaper if you build the LED lighting yourself. While this is work and requires some knowledge, it is definitely worth it.
Plants and light
Light is vital for plants. Without light, photosynthesis and therefore no growth can take place. Of course, not all light is the same. Sunlight, for example, covers a wide range of colors that we normally cannot perceive, but are of great importance to plants. When building an artificial light source from LEDs, this color spectrum must therefore be reproduced. The building light and the red light are of particular importance here. Blue light supports the plant in sprouting and generally in growing. Red light, on the other hand, plays a major role in the formation of flowers and fruits. The relevant wavelength range in which they emit is decisive for these so-called color spectra.
LED principle
LEDs have been turning the lighting market upside down for a few years now. No wonder: The small light-emitting diodes are not only significantly more efficient than the good old light bulb and require much less electricity, but can also be combined in a variety of forms. It goes without saying that, given these conditions, they are ideal for effective plant lighting. If you build your own LED plant light, individual solutions that are precisely tailored to your own needs are possible. In order for this to work, however, LEDs have to be specially wired, which requires at least some basic knowledge of electronics. You also need a power supply that converts the alternating current from the socket into direct current.
LED bar
The simplest construction of LED plant lighting is certainly that of the light bar or
Bar. Its shape is somewhat reminiscent of fluorescent tubes. Like these, it hangs freely in the room - as plant light, of course, directly above the plants that it is supposed to illuminate. The LEDs are arranged in one or more lines. In principle, the light-emitting diodes can be arranged according to very different principles, for example in the form of concentric circles. However, we want to concentrate exclusively on the linear arrangement here, because an LED bar can be built relatively easily even by relatively inexperienced people. The end result should be an LED bar with two parallel lines and a length of one meter.Material and tools
All the materials that we need for our self-made LED bar are easy and inexpensive in the hardware store or available from electronics retailers. We differentiate between the electronic components (LEDs, power supply, resistors, cables) and the construction elements such as the carrier strips and the suspension. You also need common tools that you normally already have.
LEDs
LEDs are the core elements of our LED bar. We use seven royal blue and 15 deep red LEDs, each of which is already mounted on a circuit board. You must meet the following requirements:
- Version: High Power LED
- Power: 3 watts
- Blue wavelength range: 490 to 450 nm
- Red wavelength range: 700 to 630 nm
The number of built-in LEDs can of course be changed individually. It is only important that significantly more red than blue are used.
Tip: The easiest way is to buy preconstructed LED chains or DIY kits and saves you the very complicated wiring, which can hardly be done without in-depth knowledge of electronics. We will therefore not go into more detail about the interconnection.
power adapter
The LEDs are supplied with power via the power supply unit. It converts the alternating current from the socket into the required direct current. The most important thing when choosing the right power supply unit is
Amperage. For our purposes it should be at least 700 mA. The voltage must be 24 volts or 48 volts.Tip: Used power supplies can be found in practically every household in this country. If such a used part is still functional and delivers the required amperage, it can of course be used. Under certain circumstances, this saves considerable costs and is good for the environment.
cable
Cables are required to connect the LEDs to each other and to the power supply unit. Loudspeaker cables, the so-called twin strands, are recommended here, for example. They should be 0.5 or 0.75 square millimeters thick.
Mounting materials
The following is required for the support structure of our LED bar:
- Wooden top or old table with a width of more than 100 cm
- two U-profile strips made of aluminum in the size 100 x 3 x 3 cm
- three square profiles made of plastic with a length of 100 cm
- two matching plug angles
- two matching mounting feet
- four chains with a length of 50 cm each
- thermally conductive adhesive pads
- two spacers or Distance screws with a length of approx. 15 cm
- Bolts and nuts in different sizes
- tool
A drill and metal drill is absolutely necessary for the construction of our LED bar. Alternatively, a cordless screwdriver with a metal drill bit can also be used. You also need a screwdriver and possibly a metal or metal screwdriver. Plastic saw.
construction
The construction of our LED bar is very easy. It consists of a plastic frame that is mounted on a wooden plate or an old table. The two aluminum profiles, to which the LEDs are attached, hang on chains from this frame. The profiles are guided parallel to each other and kept at a distance by means of the spacers. The power supply is external and not attached directly to the construction. For example, it can be mounted on the wooden plate. Of course, you can also do without the frame and hang the aluminum profiles directly on the ceiling. In this case, however, significantly longer chains are required. The advantage of the frame is that a special space can be created for the entire construction practically anywhere in the house or apartment. In addition, there is no need to drill holes in the ceiling.
Building instructions frame
First we build the frame from the plastic square profiles:
- Screw the two matching assembly feet on the left and right of the wooden board at a distance of one meter
- Put a square profile in each of the feet
- Attach an angle piece to the other end of each profile
- Insert the third square profile into the angle pieces and create a connection
- Drill two holes in this profile near the ends
- Insert two screws with nuts into these holes, to which the chains will later be attached
Building instructions rails
The second step is to build the actual bar and equip it with the LEDs. You should also know that LEDs should be cooled. This cooling is achieved by the U-shape of the two aluminum profile strips. The thighs dissipate the heat to a certain extent. The open side of the strips must therefore also point upwards. The LEDs are simply glued to the closed underside. It is best to use thermally conductive adhesive pads, which also promote heat dissipation. This is how you proceed step by step.
- First, two holes for the spacers resp. Drill spacer screws
- Equip the holes with the spacers and screw them together
- The distance between the two profiles should be about ten centimeters
Note: In principle, any number of profiles can be combined with one another in this way. As a rule of thumb, the more profiles, the larger the area that can be irradiated by the LEDs.
Equipped with LEDs
Once the aluminum rails have been prepared in this way, it is now time to equip the undersides of the profile with the LEDs. These are simply glued on using adhesive pads. Care should be taken to ensure that the distribution is as even as possible and that blue and red LEDs are mixed together. The connection cables are simply routed along the underside towards the sides and then diverted downwards or upwards from there. Since we have a completely switched LED chain or Using a DIY kit, we don't have to worry about the correct wiring. The cables then simply have to be routed towards the power supply unit and, if necessary, extended.
Tip: When mounting on a wooden plate, it is recommended that the power supply unit also be attached to the wooden plate.
In a final step, all you have to do is attach the chains and hang up the finished bar. The chains are simply installed by attaching the last chain link to the screws on the top of the frame and the aluminum profiles. It makes sense to secure them with a nut on both sides. The chain links can also be used to easily adjust the height as soon as the plants below the lighting grow larger.
Advantages of the LED bar
The LED bar that we have presented here offers an extremely high degree of flexibility. Above all, however, it can, to a certain extent, grow with you. The LED lighting is particularly suitable for bringing plants of all kinds in the apartment or in the house or to be able to overwinter them. Depending on the plant, it is also possible in this way to expose it to artificial light all year round - up to and including harvesting fruits and vegetables. The costs for our self-made LED bar vary, of course. However, you can assume that you have to invest between 50 and 100 euros. Compared to other plant lighting, this definitely pays off. LEDs use very little electricity, which of course saves a lot on electricity costs.
