How to power headlights?

[Mr305worldwide]

Just want to start off by saying that I have very little electronic knowledge. I'm a headlight geek and been wanting to mess around with headlights from cars, say the HID system that I pull off of headlights or LED headlights. I recently found an entire LED headlight from a car wreck. The thing is, I want to provide power to DRLs and main beams but I have no clue how to start. I want to remove the DRL and hang it up on my wall and have it work in a low power setting.

 

[littlespark]

most car headlights work from the 12v battery (14.4 usually) and more modern cars work through an on board computer, so it might not be as simple as power supply - switch - lamp.

Old filament lamps… if you put less than 12v in, you can get a dimmer lamp. But LEDs are different. They either work full bright or not at all.

You could experiment with the lamp cluster on a bench, and a 12v power supply…. Which might have to be quite heavy… check each lamps wattage (total) against what the power supply can push out.


(Ps. Too early on a Saturday… 7am in UK…. Trying to be clever and then realising I’m getting Pitbull and Flo Rida mixed up. )

 

[Lucien Nunes]

If you have complete headlight assemblies with a ballast that runs from the car's (nominal) 12V system, then all you need is an alternative source of 12-14 volts DC. There are many off-the shelf power supply units (PSUs) that will produce this from 120V AC outlet power. Some are completely enclosed power bricks that take a regular power cord e.g.

12V 20A 240W AC/DC Power Adapter, Black | LEDwholesalers

Others are designed to build into equipment and might have exposed live parts that must not be left accessible to the touch, but in the larger sizes will give you the most choice e.g.

Website Temporarily Unavailable

The power rating in watts or current rating in amps of the PSU needs to be comfortably greater than the demand of the lighting system. E.g. a 12V 20A PSU will power any device up to 240W but if the device has a starting surge of 350W then a 30A PSU is needed otherwise it might shut down. I don't know exactly what the starting requirements of car HID lamps will be, so all I can say is leave a margin of spare current capability. E.g. many headlamps will have a demand in the range 4 - 8 amps, so if you wanted to power two lamps at 8A each you might choose a unit rated at 25-30A to allow for some start-up surge.

 

[Mr305worldwide]

Ok so it looks like I'll have to start by repurposing an computer PSU into a bench PSU. Lets see how it goes from there.

 

[mainline]

Just want to start off by saying that I have very little electronic knowledge. I'm a headlight geek and been wanting to mess around with headlights from cars, say the HID system that I pull off of headlights or LED headlights. I recently found an entire LED headlight from a car wreck. The thing is, I want to provide power to DRLs and main beams but I have no clue how to start. I want to remove the DRL and hang it up on my wall and have it work in a low power setting.

Get yourself a car battery instead of a power supply to begin with.

DRL is usually just a few leds in a strip.
A DRL controller just dims those leds by around 30%

Hid lights need a starter and ballast but use less power, around 70 watts for around 3 times the brightness of a halogen type one.

If you want to be able to dim, then led is probably the easiest route.

 

[Mr305worldwide]

Would a 120v to 12v power adapter work? I just want to provide power to the headlight unit so I can tinker with it.

Also, how can I dim the DRLs with a knob?

 

[mainline]

Would a 120v to 12v power adapter work? I just want to provide power to the headlight unit so I can tinker with it.

Yes

Also, how can I dim the DRLs with a knob?

Buy yourself, a 25-30 amp variable power supply, 0 to say 15 volts dc.

There are plenty of 12v dimmers that would do what you want.

 

[Mr305worldwide]

I see. I don't think I need a variable power supply then. I just want to provide power to the headlights using the original specs. I'm going to pick up the 120 to 12v power adapter and see how it goes. Its also the cheapest route if it works.