MR16 LED bulb question

[smurfy73]

Hi,

I am brand new to the forum and know only a little about electronics.
I recently purchased some MR16 bulbs that use SMD 5050 LED's and run on 12vdc. I only need the light panel and not the casing, so I popped it open and found a circuit board inside. I have pictures of it that I will try to upload, but basically it looks like some resistors, a capacitor and a few other chips. My question is ... is this necessary to run it on 12v? I have opened these from a different manufacturer and the only thing on the light panel was a few resistors and another small device that I did not know what it was.

My goal is to be able to remove this if possible and either run the lights straight on 12v or perhaps get away with putting a resistor in line if necessary.

Thanks

 

[(*steve*)]

These things vary a lot.

Some have only the SMD 505 LEDs on them and require a constant current driver (or at least external resistors)

Many of them are simply multiple strings (typically of three) each with a current limiting resistor. These are fine for a relatively constant 12V source (which a car isn't necessarily a good example of, but...)

Some have an inbuilt regulator. These are either linear or switch mode.

Due to the current and size, linear regulators will overheat badly if you use them at high input voltages.

Switchmode regulators tend to produce the same (relatively small) amount of heat regardless of input voltage.

You can tell if it's a switchmode regulator by the presence of an inductor. This is typically the largest thing on the board and is either an obvious coil of wire, or a black (square or circular) component with only 2 connections (yeah, but not a capacitor...)

Generally speaking, if it's a switch mode device, you are safe running it with a higher voltage. Typically up to a value determined by the chip's (it's normally a chip) voltage rating, or by that of other components (such as input filter capacitors).

If you can post clear, sharp images of the board we may be able to verify your conclusion as to which type it is.

 

[smurfy73]

Thanks Steve -- I think it is a switchmode type because there does seem to be an inductor on the board. I'm going to try to attach pictures. I realize now that I took the pics straight above and you can't see that the round-ish component on the left side near the capacitor is an inductor with copper wire wound around the core.

So...do I have to run this light with this device? Or could it be run with just a resistor in line? I'm assuming that this device is regulating the voltage and the current because there are two wires coming out of it going directly to the board with the LED's with no other resistors or anything.