Can someone give me a rundown on LED versus halogen headlight bulbs, especially output and life? Stock halogen bulbs using 55 watts have a 4000K output, and I notice the Chinese imports’ output is 3200-3500K. Does that translate into less bright?
Also, the windshield wipers shudder across the windshield a lot unless there’s a huge amount of rain–changing to new blades didn’t make any difference. Any ideas? Many thanks.
No, the temperature number relates to the color of the light. 400K is bluer than 350K (K indicates Kelvins).
The shuddering could be caused by the blades hitting the glass at the wrong angle. Search google for “windshield wiper angle” to find some info on how to check and correct that.
Regarding the wiper blades, I have two suggestions:
The shuddering could be the result of a thin film of oil or other contaminant on the glass.
Frequently, a good cleaning of the windshield and the blades with isopropyl alcohol will improve wiper performance.
There are a LOT of wiper brands nowadays that are just poor quality, right out of the box. If you want really good performance from your wipers, I suggest buying Bosch Icon wiper blades. Yes, they are quite pricey, but they really are better. And, Wal-Mart carries them, at a lower price than Auto Zone and its peers charge for the same items.
Those K numbers for lights are sort of confusing. Scientists use them to compare the color of the light emitted from the bulb to the light emitted from something really hot. You know if you look inside your toaster when it is on the element there appears sort of orange-red? That’s b/c the temperature of the nichrome wire is less than 3000 degrees Kelvin . Kelvin is just another way to measure temperature, F, C, and K are the common ones. If your toaster heated up more the element would start to glow a little more white-red, then if even hotter, adding in a little blue-white color.
George, good explanation of color temperature.
Temperature is actually a way of measuring atomic activity.
Centigrade is based around a scale wherein Zero C is where water freezes and 100C is where water boils, both at set conditions of ambient pressure.
Fahrenheit’s scale has an unclear origin, a few different “origins” having been suggested.
The Kelvin scale is a scientific way of measuring that starts at the point wherein all atomic activity ceases.
It gets complicated where Kelvin is used to measure color and noise. Here’s a link to an attempted explanation, but in its attempt to simplify the definition it probably illustrates the complexity of it.