In this setup, the noble gases and metal salts are actually used as part of the lighting processes instead of as a buffer (as with halogens). The HID capsule is filled with a rich mixture of noble gases as well as alkali earth metal salts. This ballast has two main purposes One, to fire up the gas discharge process, and as a control unit to regulate a steady power flow after ignition. The ballast is an electronic module that has a circuit board lined with several small high current capacitors, transistors, and resistors. These two leads to are connected to an electronic HID ballast. HID uses a capsule (bulb) with two adjacent electrodes positioned in close proximity to each other. HID technology also known as gas discharge or xenon is quite different from old school halogens. Halogen bulbs can also be broken by a forceful jolt strong enough to fracture the filament, or by overpowering the bulbs to a degree that flash-boils the tungsten. The reason why xenon-filled halogen bulbs don't work indefinitely is because tungsten is a smaller atom and still manages to escape the xenon, redepositing itself somewhere else on the filament, which still thins the filament where the atom originally evaporated from. Xenon is most commonly used because it is the heaviest of the inert gases and is also tied to HID lighting therefore an opportunity for marketing deception arises. Once a tungsten atom leaves the surface of the filament, it is immediately blocked by giant xenon particles that are crowding it and pushing it back towards the surface of the filament. The sole purpose of these heavy gases is to create a level of pressure within the bulb that deters tungsten evaporation. Because tungsten evaporates away rather quickly, researchers learned to fill the bulbs with inert gases like argon, krypton, and yes even the infamous xenon. Now stepping back to the gas filling as mentioned earlier. In simple terms you have a dead light bulb. Sooner or later the filament will evaporate enough tungsten particles that it snaps in two pieces and breaks the electrical circuit. When the tungsten evaporates, it deposits itself on the relatively cool surface of the glass bulb (this is why dead light bulbs are often black), and the filament becomes thinner and more brittle. Secondly, as the halogen bulb is used, tungsten atoms begin to evaporate from the filament due to the extreme heat. It is a very simple technology fundamentally, but there are flaws in the halogen mostly relating to efficiency of power.įirst of all, halogen bulbs produce more heat than they do actual light (incandescence), which translates to an inefficient usage of potential energy. Fog lights operate at around 35 watts to 55 watts, and high beams at 55 watts to 85 watts. Halogen low beams will normally operate on 55 watts of power. This is essentially the same principle of operation as fire: intense heat used to produce light. It is this high resistance that produces heat and ultimately light as a byproduct. When electrical current is supplied to the positive lead wire in the halogen bulb, it crosses a path of tungsten wire, which has very high electrical resistance. The bulb itself is also filled with a noble gas of some sort, which we'll get into later. On some bulbs, like the 9006/HB4, the glass bulb that encases them is capped at the end with a nickel-plated brass film. The filament is held up by two chemically-treated, copper-coated steel (or molybdenum) lead wires. The bulb itself houses a filament commonly made of tungsten metal, which is basically a very delicate loose coil of exotic wire. Halogen lighting involves a conventional direct-current direct-circuit setup. Halogen is what has been used in automotive lighting for the last 50 years or so and has peaked in its technological advancement. Before there was HID technology, there was halogen lighting. First a background of automotive lighting technology.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |