LEDs are becoming increasingly popular for home lighting. They can be used in various forms. The connection diagram of the LED strip depends on its type and power. There are many options for connecting these lights to various power supplies.
Design types of LED strips
This is a general term used to describe various types of LED devices made in the form of flexible strips (tapes). Depending on how you plan to use the LEDs, you will need one or another type of design. For example, in rooms such as bathrooms, closed waterproof tapes are best. To indicate tracks in the dark, you can choose aluminum strips with LEDs. In order to simplify installation, flexible self-adhesive tapes can be used.
But we are no longer interested in their design, but in the connection schemes of LED LED strips, which are determined by their own electrical circuits. They, in turn, depend on the number and number of types (colors) of LEDs in the tape
LED strip colors
They have a very wide range of glow colors. The most massive of them are called monochrome (English singl color strip) and glow with one unchanged hue. They are cheap, affordable, and generally easier to install.
Their second type is called RGB tapes. They can display any color obtained by mixing red, green, and blue, just like a color picture tube does. In it, for each element of the image, three closely located parts of the screen with the above three colors are used. By adjusting the beam of the kinescope, the intensity of the glow of a particular area, the color of the image element corresponding to the transmitted air is obtained.
RGB tape is built on a similar principle. It can either consist of the so-called LED triads, which are three adjacent and parallel connected red, green and blue LED strips, or from specially made combined triple strips enclosed in one housing.
Such tapes have a small controller, which allows you to control the LEDs of each color on an individual basis from the control panel, including remotely.
Monochrome LED strip device
Monochrome models are most simply arranged. Along the length of the tape laid two parallel printed copper bus tracks. One of them joins the "plus" of the power source, and the second - to the "minus". LEDs are installed between them, and all of them are oriented in the same way: to the “plus” anodes to, and the negative bus to the cathodes. On the case of each of them from the side facing the negative bus (from the side of its cathode), one of the corners is cut off, moreover, all have the same side. This makes it easier to determine the polarity of the tape power bus.
In addition, along its entire length on the tires there are groups of four contact pads with “+” and “─” signs, which serves the same purpose. Between pairs of sites in each such group, cut lines are drawn perpendicular to the edges of the tape with a symbol in the form of scissors. Connecting an LED strip with your own hands often requires cutting it into pieces, which is done along these lines.
Connection of diodes in monochrome tapes
The rated supply voltage of the tapes is either 12 V or 24 V. In the first case, all the diodes are divided into triads connected in parallel between the power buses. That is, their number between neighboring groups of contact pads is a multiple of three. Each of their triads is three LEDs connected in series through current-limiting resistors (from one to three).
For a tape with a rated voltage of 24 V, instead of triads between the buses, a larger number of consecutive diodes is switched on - up to 10 pieces.
RGB tape device
Consider it as an example of a product with combined (three in one housing) LEDs. Such an electronic element has six leads on opposite sides of its housing, with all the anodes being brought out on one side and the cathodes on the opposite. All diodes face their anodes to one edge of the tape. On the opposite side of their housings (on the cathode side, but sometimes vice versa, on the anode side), like monochrome LEDs, one of the corners is cut to facilitate polarity determination.
Along the length of the tape, groups of eight contact pads are periodically located, symmetrically on four located on both sides of the cut lines, indicated by the symbol of scissors. The RGB LED strip connection scheme often requires cutting it into pieces, which helps to implement the above lines.
The two extreme neighboring pads in each group are marked with a “+” sign, under which are the nominal voltage values, and the other three pairs of neighboring pads are marked with the letters “R”, “G”, “B”. All of them are located on the power bus of the same name. Thus, there are four such tires on the tape. At the same time, three "letter" tires run in parallel along one of its edges, to which the anodes of the diodes are facing, and a "positive" bus runs along its opposite edge, to which their cathodes are facing.
Connecting diodes in RGB tapes
If the tape is positioned so that the contact pads on the “positive” bus are on top, then the anodes of the three internal diodes of each combined LED located first to the left of the pads will be output to the common “positive” power bus. Further, when shifted to the right, all diodes of the same color are connected in series with the leftmost one until the cathode of each of them is displayed on the same right contact pad of this segment of the tape. Between adjacent devices, series-limiting resistors are connected in series.
Neighboring platforms of the same color, located between two cutting lines, are directly connected by segments of the respective tires. So the RGB LED strip connection scheme allows you to apply voltage to it from any side.
General tips for mounting LED strips
Never buy them without first specifying how you will install. Connecting an LED strip with your own hands can in some cases be as simple as plugging a portable lamp into a wall outlet. In others, it will have to be cut, removed and stripped connecting wires, install special connectors on them, or connect them to the output terminals of various power supplies.
With regard to installation, always first consider the following factors:
• Required tape length / number.
• Power consumption and supply voltage.
• The location of the LEDs on the tape.
• The degree of its flexibility.
• Does the planned LED strip connection plan need components such as connectors?
• Is there a need to program it.
LED strip power
Before buying any of them, you will need to determine the permissible power consumption. The wiring diagram of the LED strip largely depends on this parameter. First, you need to make sure that your power outlet can meet the energy needs of LEDs. It is quite simple to calculate.
Find out how much power your power supply can provide. For example, a typical power outlet is rated at 15 A. At 220 V, the line voltage reaches 3300 watts. It is recommended that you never load the source with more than 80% of its power, so do not connect more than 2640 watts. On the specification of the tape that you want to buy, you need to find power. Please note that it is sometimes indicated on the drum - the unit of delivery from the factory per unit length (ft or meter) or LED. In the last two options, you need to calculate how many feet (meters) of tape or how many diodes will be used in your overall project, and multiply by the indicated power. This will let you know if your LED strip connection scheme is safe.
Another reason to pay attention to the power of LED strips is energy consumption. Even with the low power consumption of LEDs (compared to most other types of lighting fixtures), their total number of several hundred will still increase your electricity bills.
Connecting an LED strip to a computer
This is a very common way of powering LED strips, since a typical switching power supply unit (UPS) of a PC, as a rule, has one of the voltage outputs of exactly 12 V, which corresponds to the nominal supply voltage of most monochrome models. It is important here not to make a mistake when determining the permissible load on the UPS. Each of them has a plate indicating the rated current for each output voltage. A typical UPS with a total power of 400 W at a voltage of 12 V allows a current of 16 A, which corresponds to 190 W. The specific power consumption of typical LED-strips at 12 V is in the range from 2.5 to 14.5 W / m.
Connecting an LED Strip Power Supply
The option of connecting the LED strip to the PC UPS is still, so to speak, “contingent”, adapted. Currently, the market offers a lot of different power supply devices that are connected to the mains, with an output of 12 and 24 V. Among them there are both universal application units and specialized devices for powering LED strips. When choosing them, one must take into account the above recommendations for determining the permissible power consumption of the lighting load and the correspondence of its rated power to the power source.
How to control the glow of RGB-tapes
Above, when considering the location of the diodes in these lighting devices, it was noted that they are connected in three parallel branches, in each of which only one color LED is connected in series. Accordingly, the connection of the controller to the LED strip means the connection to the supply voltage of each of these three branches through its transistor switch controlled by the controller chip.
Included is a remote control. It has an infrared LED emitting in the infrared range, and on the controller block there is a receiving infrared sensor controlled by a special microcircuit.
The connection diagram of the LED strip controller involves connecting it to the mains via a power supply with an output of 24 V.
Often, RGB tapes are sold bundled with it and RGB controllers, and their input and output connectors correspond to each other, and a connecting cable is also included.