One-hundred-and-thirty years ago, Thomas Edison completed the initial successful sustained test of the incandescent light bulb. With some incremental improvements along the way, 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 which will ultimately replace Edison’s bulbs with a a lot more energy-efficient lighting solution. Solid state LED lighting could eventually replace almost all of the numerous huge amounts of incandescent and fluorescent lights in use around the world today. In fact, as a step along this path, The President last June unveiled new, stricter lighting standards that will support the phasing out of incandescent bulbs (which already are banned in parts of Europe).
To understand precisely how revolutionary led driver ul are in addition to why these are still expensive, it is instructive to look at the way they are made and to compare this to the creation of incandescent bulbs. This article explores how incandescent bulbs are created and after that contrasts that process having a description of the typical manufacturing process for LED lights.
So, let’s begin by examining how traditional incandescent lights are manufactured. You will see that this is a classic illustration of a computerized industrial process refined in more than a century of experience.
While individual incandescent light bulb types differ in dimensions and wattage, every one of them have the three basic parts: the filament, the bulb, and also the base. The filament consists 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 manufactured from nickel-iron wire. This wire is dipped in to a borax means to fix make the wire more adherent to glass. The bulb itself is made of glass and contains a blend of gases, usually argon and nitrogen, which boost the lifetime 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 can be used on the outside and glass utilized to insulate the inside the base.
Originally produced by hand, bulb manufacturing is now almost entirely automated. First, the filament is manufactured utilizing a process known as drawing, by which tungsten is blended with a binder material and pulled by way of a die (a shaped orifice) into a fine wire. Next, the wire is wound around a metal bar known as a mandrel in order to mold it into its proper coiled shape, and then its heated in a process called annealing, softening the wire and makes its structure more uniform. The mandrel will be dissolved in acid.
Second, the coiled filament is linked to the lead-in wires. The lead-in wires have hooks at their ends which can be either pressed over the end of the filament or, in larger bulbs, spot-welded.
Third, the glass bulbs or casings are produced employing 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 within the conveyor belt into molds, creating the casings. A ribbon machine moving at top speed can produce greater than 50,000 bulbs each hour. After the casings are blown, they may be cooled and after that cut off of the ribbon machine. Next, the inside of the bulb is coated with silica to remove the glare the consequence of glowing, uncovered filament. The label and wattage are then stamped onto the outside top of each casing.
Fourth, the bottom of the bulb is additionally constructed using molds. It is produced with indentations inside the form of a screw so that it can easily match the socket of any light fixture.
Fifth, once the filament, base, and bulb are created, these are fitted together by machines. First, the filament is mounted to the stem assembly, using its ends clamped towards the two lead-in wires. Next, the air within the bulb is evacuated, as well as the casing is full of the argon and nitrogen mixture.
Finally, the base and also the bulb are sealed. The base slides onto the end in the glass bulb such that not one other material is needed to keep them together. Instead, their conforming shapes allow the two pieces to be held together snugly, with the lead-in wires touching the aluminum base to make sure proper electrical contact. After testing, bulbs are positioned in their packages and shipped to consumers.
Light bulbs are tested for lamp life and strength. So that you can provide quick results, selected bulbs are screwed into life test racks and lit at levels far exceeding normal. This gives an exact measure of how long the bulb can last under normal conditions. Testing is performed in any way manufacturing plants as well as at some independent testing facilities. The typical life of the standard household bulb is 750 to one thousand hours, according to wattage.
LED light bulbs are made around solid-state semiconductor devices, therefore the manufacturing process most closely resembles that used to make electronic products like PC mother boards.
An easy-emitting diode (LED) is a solid state electrical circuit that generates light from the movement of electrons in a semiconductor material. LED technology has been around since the late 1960s, but for the first forty years LEDs were primarily used in electronics devices to change miniature bulbs. Within the last decade, advances within the technology finally boosted light output sufficient for LEDs to begin to seriously contest with incandescent and fluorescent bulbs. Just like many technologies, as the cost of production falls each successive LED generation also improves in light quality, output per watt, and heat management.
The pc industry is well suited to manufacture LED lighting. The process isn’t a great deal diverse from building a computer motherboard. The companies making the LEDs are generally not in the lighting business, or it really is a minor part of their business. They are usually 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 partly as it takes a number of LEDs to get wide-area illumination rather than a narrow beam, and also the assembly cost enhances the overall price. In addition, assemblies consisting of arrays of LEDs create more opportunities for product defects.
An LED light contains four essential components: an LED circuit board, a heatsink, an electrical supply, along with a shell. The lights start off as bare printed circuit boards (PCB) and high luminance LED elements arrive from separate factories which focus on making those components. LED elements themselves create some heat, and so the PCB utilized in lighting is special. Instead of the standard non-conductive sandwich of epoxy and fiberglass, the circuit board is organized over a thin sheet of aluminum which behaves as a heatsink.
The aluminum PCB found in LED lighting is coated having a non-conducting material and conductive copper trace lines to form the circuit board. Solder paste is then applied in the right places and after that Surface Mount Technology (SMT) machines position the tiny LED elements, driver ICs, and other components to the board at ultra high speeds.
The round model of a conventional light implies that most LED printed circuit boards are circular, so for easy handling some of the smaller circular PCBs are combined into one larger rectangular PCB that automated SMT machinery can handle. Consider it just like a cupcake tray moving in one machine to another along a conveyor belt, then in the end the individual cupcakes are snapped free of the tray.
Let’s have a look at the manufacturing steps for any typical LED light bulb intended to replace a standard incandescent bulb with an Edison Screw. You will find that it really is a completely different process from the highly automated processes employed to manufacture our familiar incandescent bulbs. And, despite whatever you might imagine, people are still greatly an essential part of manufacturing process, and not merely for testing and Quality Assurance either.
When the larger sheets of LED circuit boards have passed via a solder reflow oven (a heat furnace that melts the solder paste), they are split up in to the individual small circuit boards and power wires manually soldered on.
The small power supply housed in your body from the light bulb experiences an identical process, or might be delivered complete from another factory. Either way, the manufacturing steps are the same; first the PCB passes through SMT lines, this would go to a manual dual in-line package (DIP) assembly line where a long row of factory workers add one component at a time. DIP refers back to the two parallel rows of leads projecting from the sides in the package. DIP components include all integrated chips and chip sockets.
While Leds burn several times over incandescent or CFLs and require less than half the power, they require some type of passive heatsink keep the high-power LEDs from overheating. The LED circuit board, which is manufactured out of 1.6-2mm thick aluminum, will conduct the heat through the dozen or so LED elements for the metal heatsink frame and thus keep temperatures under control. Aluminum-backed PCBs are sometimes called “metal core printed circuit boards,” and though manufactured from a conductive material the white coating is electrically isolating. The aluminum PCB is screwed in place within the heatsink which forms the low one half of the LED bulb.
After that, the energy connector board is fixed in place with adhesive. The small power supply converts 120/240V AC mains capacity to a lower voltage (12V or 24V), it fits in the cavity behind the aluminum PCB.
Shell assembly contains locking the shell in position with screws. A plastic shell covers the energy supply and connects with the metal heatsink and LED circuit board. Ventilation holes are included to enable hot air to avoid. Wiring assembly for plug socket requires soldering wires to the bulb socket. Then shell is attached.
Next, the completed LED light is delivered to burn-in testing and quality control. The burn-in test typically can last for thirty minutes. The completed LED bulb will then be powered up to see if it is actually in working order and burned set for thirty minutes. There is also a high-voltage leakage and breakdown test and power consumption and power factor test. Samples from your production run are tested for high-voltage leaks, power consumption, and power factor (efficiency).
The finished bulbs pass through one final crimping step as the metal socket base is crimped in place, are bar-coded and identified with lot numbers. External safety labels are applied and the bulb is inked with information, such as brand and model number. Finally, all that’s left is to fix on the clear plastic LED cover that is glued in position.
After a final check to make certain all the different areas of the LED light are tight, then its packed into individual boxes, and bulbs are shipped out.
So, in case you have wondered why LED light bulbs are really expensive today, this explanation of how they are manufactured and exactly how that comes even close to the creation of traditional light bulbs should help. However, it jrlbac reveals why the price will fall pretty dramatically on the next several years. Just as the price of manufacturing other semiconductor-based products has fallen dramatically because of standardization, automation along with other key steps across the manufacturing learning curve, the identical inexorable forces will drive on the costs of LED bulb production.