probably mostly arduino, but hey… i like you guys in here!
so i’m running some ws2812b (and eventually attiny45) from a cars headlight, which the lamp is rated to 12v 55a. now i know that its AC, so what would be a nice small compact way to get the cars 11-15v down to a nice stable 5v?
do i need to worry about the 55a so much, or will my electronics just take what they need?
my project should only use negligable for the attiny45, and 960mA max for the leds, so im just going to chip on to the main beam power.
Cars use a DC system. If you aren’t drawing too much current, a simple linear regulator is fine. If you want a little less heat you can use a switching BEC for RC models. You can get them cheap.
even the front headlights? the non polarity lamps?
Unless they are hid’s and then the ballast is putting out thousands of volts lol.
Look at this on eBay http://www.ebay.co.uk/itm/272258563508
If you’re not local to the UK, there might be someone else selling them
I would get something like Castle Creations CC Bec 10A 6S Switching Regulator https://www.amazon.com/dp/B000MXAR12/ref=cm_sw_r_cp_apa_uaEyxb83B2EFP or US Ship Hobbywing 5V/6V 3A Switch-mode UBEC, Max 5A Lowest RF https://www.amazon.com/dp/B008ZNWOYY/ref=cm_sw_r_cp_apa_weEyxbP244MS8
the “car” solution is a 5 pin 12v relay, wired to the main beam, ecu and side doors… im not gonna lie, im totally lost… but in the car world there’s loads of knowitalls!
dropt the 12v down to 5v and im golden. i have plenty of lm17085’s on hand 
