LEDs that can be driven from a 12v source

[clint357]

I thought we could compile a list of LEDs and how they can be driven from a vehicles' power supply. Here's a couple to start with.

SSC P7 - Kaidomain P7 driver
Bridgelux C2000 - CCHIPO

 

[ecotack]

I was thinking any LED with the correct resistor. Remembering cars can spike to 15v. I usually calculate resistor for 14v to be on the safe side.

DX do a few 12v drivers for 1W and 3W LEDs. I've used SKU:13557 for 3W and SKU:26110 for 5W (e.g., Cree XR-Es). A nice small two level driver for Stop/Tail applications is what I need.

 

[clint357]

I was thinking any LED with the correct resistor. Remembering cars can spike to 15v. I usually calculate resistor for 14v to be on the safe side.

DX do a few 12v drivers for 1W and 3W LEDs. I've used SKU:13557 for 3W and SKU:26110 for 5W (e.g., Cree XR-Es). A nice small two level driver for Stop/Tail applications is what I need.

Resistors drop the voltage by turning it into heat, which sucks. Also, an led needs to be driven with a specific current, not a stable voltage so a resistor on a vehicle's power supply would not work well at all.

 

[tay]

For just plain superflux LEDs, people have gotten good results with LDO regulators, and brightness control via PWM. I wouldn't consider running any serious LED setup beyond a few diodes off of a resistor. You want lights that work with a 12v supply, and with a 15v supply. If you spec it out for 12v, it will overdrive them at 15v. If you spec it out for 15v, they might not light up at 12v.

better way is to just get a LDO regulator that will give you a stable voltage. still not as good as a constant current driver, but probably fine for low-power applications.

 

[TorchBoy]

Re: LEDs that can be driven from a 12 V source

I thought we could compile a list of LEDs and how they can be driven from a vehicles' power supply.

I thought this might be a list of LEDs that could be driven from 12 V directly, without a need for external current limiting. For suitable drivers, would a filter for automotive use on my driver list be of any help?

Resistors drop the voltage by turning it into heat, which sucks. Also, an led needs to be driven with a specific current, not a stable voltage so a resistor on a vehicle's power supply would not work well at all.

For low power (ie, 5 mm) LEDs a resistor is certainly the most cost effective way of driving them, and driving three LEDs of any power in series may be no less efficient than a buck driver, which means the same amount of "waste" heat to be dissipated. (I put "waste" in quote marks because it's really a necessary cost, not simply wasted.)

The resistor provides current limiting - a resistor resists current flow. Resistors work well in many automotive LED situations and the variable input voltage is often not enough to be a problem (the amount of light produced doesn't change by as much as feared). There are pros and cons to resistors, and there are pros and cons to the different types of drivers.