I got these from China for my GTI's cornering lights. They were cheap as chips so worth the risk. BUT they are bright, headache inducing bright if you look directly at them. LED is the future and they have come on incredibly over the last year.
Headlight bulb?
- Thread starter danlightbulb
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Caporegime
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Philips xtreme vision+ are worth a punt.
After also having the same problem with Nightbreakers, I switched over to Philips Xtreme Vision+ and they have been in my M3 now for 2.5 years (with a lot of use), and in my girlfriends/parents/sisters car for similar time and they're going as well as ever.
Soldato
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"A flame that burns twice as bright burns only half as long".
After switching from standards to ultra bright I got tired of only getting about a year to 18mths out of a bulb. Once one went the other was sure to go shortly after.
Switched to "high mileage" bulbs which are only standard brightness but have thicker filaments and didn't have a headlight failure for the last four years of owning the car.
After switching from standards to ultra bright I got tired of only getting about a year to 18mths out of a bulb. Once one went the other was sure to go shortly after.
Switched to "high mileage" bulbs which are only standard brightness but have thicker filaments and didn't have a headlight failure for the last four years of owning the car.
Soldato
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Are they any good though? I've read up on LED bulbs for headlights and the reviews always seem to state that they're bright, but don't have the right beam patter or throw for headlights. eg http://www.candlepowerforums.com/vb...Yes-another-LED-Headlight-conversion-question
Gone for those. I noticed that lifespan advertised as 450h. The listed lifespan of Nightbreakers unlimited is 150-250h only.
From Wiki
Incandescent lamps are very sensitive to changes in the supply voltage. These characteristics are of great practical and economic importance.
For a supply voltage V near the rated voltage of the lamp:
- Light output is approximately proportional to V 3.4
- Power consumption is approximately proportional to V 1.6
- Lifetime is approximately proportional to V −16
- Color temperature is approximately proportional to V 0.42
The relationships above are valid for only a few percent change of voltage around rated conditions, but they do indicate that a lamp operated at much lower than rated voltage could last for hundreds of times longer than at rated conditions, albeit with greatly reduced light output. The "Centennial Light" is a light bulb that is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb emits the equivalent light of a four watt bulb. A similar story can be told of a 40-watt bulb in Texas that has been illuminated since 21 September 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, and was moved to an area museum in 1977.[124]
In flood lamps used for photographic lighting, the tradeoff is made in the other direction. Compared to general-service bulbs, for the same power, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as two hours for a type P1 lamp). The upper temperature limit for the filament is the melting point of the metal. Tungsten is the metal with the highest melting point, 3,695 K (6,191 °F). A 50-hour-life projection bulb, for instance, is designed to operate only 50 °C (122 °F) below that melting point. Such a lamp may achieve up to 22 lumens per watt, compared with 17.5 for a 750-hour general service lamp.[61]
Lamps designed for different voltages have different luminous efficacy. For example, a 100-watt, 120-volt lamp will produce about 17.1 lumens per watt. A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens per watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt.[61] Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.
The wires used to support the filament make it mechanically stronger, but remove heat, creating another tradeoff between efficiency and long life. Many general-service 120-volt lamps use no additional support wires, but lamps designed for "rough service" or "vibration service" may have as many as five. Low-voltage lamps have filaments made of heavier wire and do not require additional support wires.
Very low voltages are inefficient since the lead wires would conduct too much heat away from the filament, so the practical lower limit for incandescent lamps is 1.5 volts. Very long filaments for high voltages are fragile, and lamp bases become more difficult to insulate, so lamps for illumination are not made with rated voltages over 300 volts.[61] Some infrared heating elements are made for higher voltages, but these use tubular bulbs with widely separated terminals.
TL;DR
Brightness in a filament bulb is achieved at the expense of service life. However the relationship is far, far, more aggressive than 2 for 1/2.
WRT vehicles, the really important bit is the relationship between life and supply voltage.
High brightness filament bulbs are likely to be unsuitable for more modern vehicles with