12.5 Volt Battery To 11 Volt LED Fixture
Brand new 28 watt fixture given to me free. Originally 120 VAC. Stripped the regulator out for pure DC operation, emergency lighting off a smaller car jar battery. I am going to power it off the batte...
Forum Discussion
Hello,
I'm an engineer with some semiconductor physics experience:
The diodes that are at the core of the LED are actually current devices- they drop a narrow range of voltage across the junction that is controlled by the current forced through them. The voltage drop is highly dependent on the junction temperature of the diode and the materials used to build it. If you directly drive that junction with a low impedance voltage source without a regulation device, the current will be way too high and the metals and doping in the semiconductor will migrate around and ruin the diode.
Low power LED's usually use resistors as current control devices, but lighting devices actually use a current regulator. By removing the regulator you risk frying the LED's in short order, or at least changing the color spectrum and lowering the light output. If you are going to change the power supply, make sure you actually design it to regulate the current instead of shooting for some nominal voltage.
I'm an engineer with some semiconductor physics experience:
The diodes that are at the core of the LED are actually current devices- they drop a narrow range of voltage across the junction that is controlled by the current forced through them. The voltage drop is highly dependent on the junction temperature of the diode and the materials used to build it. If you directly drive that junction with a low impedance voltage source without a regulation device, the current will be way too high and the metals and doping in the semiconductor will migrate around and ruin the diode.
Low power LED's usually use resistors as current control devices, but lighting devices actually use a current regulator. By removing the regulator you risk frying the LED's in short order, or at least changing the color spectrum and lowering the light output. If you are going to change the power supply, make sure you actually design it to regulate the current instead of shooting for some nominal voltage.
