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A lot of modern cars only have a single LED bulb that provides normal headlights and high beams. In the past with halogen headlights they'd either have two sep
by Merad 4y ago
A lot of modern cars only have a single LED bulb that provides normal headlights and high beams. In the past with halogen headlights they'd either have two separate bulbs or a single complex bulb with two different filaments for normal and high beams. I would assume LED + PWM lets them have a single bulb whose brightness can be controlled by software, so the choice is probably more about cost savings and reducing complexity than energy usage.
- akira2501 4y agoIt does seem entirely overkill to not just install a second LED. That's how bulbs have worked for years. So instead of just adding _one_ additional LED we're going to oversize that LED and then use a high frequency driver to turn it on and off really fast?
- wolpoli 4y agoI don't have a car with LED bulb so I can't check, but I wonder how would one bulb works when normal and high beams have different beam pattern. One might be able to accomplish that with one LED bulb if it switches on/off certain LEDs in the module or the bulb is movable, but then no PWM is required.
- rootusrootus 4y agoA typical pre-LED solution is a projector and a mechanical plate that moves (very quickly) to block or unblock the part of the light that makes up the high beam coverage. LEDs can be done similarly, but an LED matrix headlight just controls which rows of LEDs are lit up (e.g. the Samsung PixCell light that Tesla uses on the Model 3/Y). This is where we'll maybe see adaptive headlights, too, though in the case of Tesla I don't believe they've ever been used anywhere in the world, legal or not. Just to write "TESLA" on the wall when you do the Light Show.