One-hundred-and-thirty years ago, Thomas Edison completed the first successful sustained test of the incandescent bulb. With many incremental improvements in the process, Edison’s basic technology has lit the world ever since. This is going to change. We are on the cusp of a semiconductor-based lighting revolution that will ultimately replace Edison’s bulbs with a far more energy-efficient lighting solution. Solid state LED lighting will eventually replace almost all the countless billions of incandescent and fluorescent lights in use around the world today. Actually, as a step along this path, President Obama last June introduced new, stricter lighting standards which will support the phasing out of incandescent bulbs (which already are banned in areas of Europe).
To understand just how revolutionary Ultrathin Constant Voltage Waterproof Power Supply are along with why they may be still expensive, it is actually instructive to check out the way they are produced and to compare this for the manufacture of incandescent bulbs. This post explores how incandescent light bulbs are created then contrasts that process having a description from the typical manufacturing process for LED lights.
So, let’s start by considering how traditional incandescent lights are made. You will notice that it is a classic illustration of a computerized industrial process refined in more than a century of expertise.
While individual incandescent bulb types differ in dimensions and wattage, every one of them possess the three basic parts: the filament, the bulb, as well as the base. The filament is made of tungsten. While very fragile, tungsten filaments can withstand temperatures of 4,500 degrees Fahrenheit and above. The connecting or lead-in wires are typically made of nickel-iron wire. This wire is dipped right into a borax means to fix create the wire more adherent to glass. The bulb itself is made of glass and has a blend of gases, usually argon and nitrogen, which increase the life of the filament. Air is pumped out of the bulb and substituted for the gases. A standardized base supports the entire assembly in position. The base is called the “Edison screw base.” Aluminum is used on the outside and glass used to insulate the within the base.
Originally produced by hand, light manufacturing is currently almost entirely automated. First, the filament is manufactured employing a process referred to as drawing, in which tungsten is mixed with a binder material and pulled via a die (a shaped orifice) in to a fine wire. Next, the wire is wound around metallic bar known as a mandrel in order to mold it into its proper coiled shape, and then it is heated in a process called annealing, softening the wire and makes its structure more uniform. The mandrel is then dissolved in acid.
Second, the coiled filament is connected to the lead-in wires. The lead-in wires have hooks at their ends which can be either pressed on the end from the filament or, in larger bulbs, spot-welded.
Third, the glass bulbs or casings are designed utilizing a ribbon machine. After heating in a furnace, a continuous ribbon of glass moves along a conveyor belt. Precisely aligned air nozzles blow the glass through holes inside the conveyor belt into molds, creating the casings. A ribbon machine moving at top speed can produce greater than 50,000 bulbs each hour. Following the casings are blown, they may be cooled and after that cut from the ribbon machine. Next, the within the bulb is coated with silica to get rid of the glare the consequence of glowing, uncovered filament. The label and wattage are then stamped on the outside top of each casing.
Fourth, the base of the bulb can also be constructed using molds. It is made with indentations within the model of a screw so that it can easily match the socket of the light fixture.
Fifth, when the filament, base, and bulb are produced, they may be fitted together by machines. First, the filament is mounted for the stem assembly, with its ends clamped to the two lead-in wires. Next, the environment in the bulb is evacuated, and also the casing is full of the argon and nitrogen mixture.
Finally, the base as well as the bulb are sealed. The base slides to the end in the glass bulb such that not one other material is needed to keep these together. Instead, their conforming shapes enable the two pieces to get held together snugly, using the lead-in wires touching the aluminum base to make sure proper electrical contact. After testing, bulbs are placed inside their packages and shipped to consumers.
Light bulbs are tested for both lamp life and strength. In order to provide quick results, selected bulbs are screwed into life test racks and lit at levels far exceeding normal. This supplies an accurate measure of how much time the bulb may last under normal conditions. Tests are performed whatsoever manufacturing plants as well as at some independent testing facilities. The normal lifetime of the standard household bulb is 750 to 1,000 hours, according to wattage.
LED light bulbs are built around solid-state semiconductor devices, so the manufacturing process most closely resembles that employed to make electronic goods like PC mother boards.
A mild-emitting diode (LED) is actually a solid state electrical circuit that generates light through the movement of electrons in a semiconductor material. LED technology has been around since the late 1960s, but also for the first 4 decades LEDs were primarily found in electronics devices to switch miniature lights. In the last decade, advances inside the technology finally boosted light output sufficient for LEDs to begin with to seriously contest with incandescent and fluorescent light bulbs. Just like many technologies, as the price of production falls each successive LED generation also improves in light quality, output per watt, and also heat management.
Your computer sector is well suited to manufacture LED lighting. The process isn’t a lot distinct from making a computer motherboard. The businesses making the LEDs are generally not in the lighting business, or it really is a minor a part of their business. They tend to be semiconductor houses which are happy cranking out their product, which is why prices on high-output LEDs has fallen a lot during the last fifteen years.
LED bulbs are expensive to some extent because it takes a number of LEDs to get wide-area illumination instead of a narrow beam, and the assembly cost adds to the overall price. Furthermore, assemblies consisting of arrays of LEDs create more opportunities for product defects.
An LED light includes four essential components: an LED circuit board, a heatsink, a power supply, and a shell. The lights start off as bare printed circuit boards (PCB) and high luminance LED elements arrive from separate factories which specialize in making those components. LED elements themselves create a bit of heat, and so the PCB utilized in lighting fixtures is special. Rather than the standard non-conductive sandwich of epoxy and fiberglass, the circuit board is laid out on the thin sheet of aluminum which acts as a heatsink.
The aluminum PCB utilized in LED lights are coated having a non-conducting material and conductive copper trace lines to make the circuit board. Solder paste will then be applied in the right places and then Surface Mount Technology (SMT) machines position the tiny LED elements, driver ICs, along with other components to the board at ultra high speeds.
The round shape of a traditional bulb signifies that most LED printed circuit boards are circular, so for ease of handling a lot of the smaller circular PCBs are combined into one larger rectangular PCB that automated SMT machinery are designed for. Consider it just like a cupcake tray moving from a single machine to another along a conveyor belt, then in the end the individual cupcakes are snapped clear of the tray.
Let’s have a look at the manufacturing steps for any typical LED light bulb meant to replace a regular incandescent bulb having an Edison Screw. You will see that this is a very different process through the highly automated processes used to manufacture our familiar incandescent bulbs. And, despite everything you might imagine, folks are still very much an essential element of manufacturing process, and not merely for testing and Quality Assurance either.
After the larger sheets of LED circuit boards have passed via a solder reflow oven (a hot air furnace that melts the solder paste), they are broken up in to the individual small circuit boards and power wires manually soldered on.
The tiny power source housed in the body in the light experiences a comparable process, or could be delivered complete from another factory. Either way, the manufacturing steps are similar; first the PCB passes through SMT lines, this goes toward a manual dual in-line package (DIP) assembly line where a long row of factory workers add one component at any given time. DIP refers back to the two parallel rows of leads projecting from your sides from the package. DIP components include all integrated chips and chip sockets.
While Leds burn many times longer than incandescent or CFLs and require not even half the vitality, they require some type of passive heatsink keep your high-power LEDs from overheating. The LED circuit board, which is made of 1.6-2mm thick aluminum, will conduct the temperature through the dozen approximately LED elements towards the metal heatsink frame and therefore keep temperatures under control. Aluminum-backed PCBs are occasionally called “metal core printed circuit boards,” even though made of a conductive material the white coating is electrically isolating. The aluminum PCB is screwed in position inside the heatsink which forms the reduced half of the LED light bulb.
After this, the energy connector board is fixed in place with adhesive. The little power supply converts 120/240V AC mains power to a lower voltage (12V or 24V), it suits the cavity behind the aluminum PCB.
Shell assembly contains locking the shell in position with screws. A plastic shell covers the power supply and connects using the metal heatsink and LED circuit board. Ventilation holes are included to permit heat to escape. Wiring assembly for plug socket requires soldering wires to the bulb socket. Then shell is attached.
Next, the completed LED light is sent to burn-in testing and quality control. The burn-in test typically will last for 30 minutes. The completed LED light is then powered up to find out if it is functioning properly and burned in for half an hour. There is also a high-voltage leakage and breakdown test and power consumption and power factor test. Samples from the production run are tested for high-voltage leaks, power consumption, and power factor (efficiency).
The finished bulbs pass through one final crimping step since the metal socket base is crimped set up, are bar-coded and identified with lot numbers. External safety labels are applied and the bulb is inked with information, such as brand name and model number. Finally, all that’s left is to fix on the clear plastic LED cover which is glued in place.
After a final check to make certain all the different areas of the LED light are tight, then it is packed into individual boxes, and bulbs are shipped out.
So, if you have wondered why LED lights are extremely expensive today, this explanation of how they are manufactured and exactly how that comes even close to the manufacture of traditional bulbs should help. However, it jrlbac reveals why the cost will fall pretty dramatically within the next several years. Just like the expense of manufacturing other semiconductor-based products has fallen dramatically as a result of standardization, automation and other key steps along the manufacturing learning curve, the same inexorable forces will drive on the costs of LED light bulb production.