lazarus2405 wrote:parabellum wrote:granolaboy wrote:Could one skip the step-down module if one already has a dc-dc converter putting out 12v?
Yes, they initially are designed for 12v vehicle application, there is limiting resistor inside the light casing.
As in, you looked in and found one? If it's just a dumb ballast resistor, that's awfully disappointing. The description states "with High precision constant current drive, make
sure that the brightness is same under any input voltage." That sounds like to me an actual buck LED driver instead of a simple voltage step-down. Are you willing to open up all the guts and post pictures?
I hope you read carefully and look all pictures before asking. Anyway, if you look the product picture and description, you will see external step down module which brings the voltage to 12V so it is CV (I doubt it is also CC) , now "inside the light casing" is what you call "dumb ballast resistor" and it looks like all chips are connected in series to it. All this makes me think, they took ordinary car/motorcycle light and attached step down module to it
Also, I can't find specs for the actual emitters. Going on "USA BrigeLux 45mil chip" leads me to this data sheet, but that product is much "bluer" than I'd expect this light to look. (Dominant wavelengths all right around 450nm is really blue, not white with a blueish tint.)
You know that you are linking to "BRIDGELUX BLUE POWER DIEBXCE 24 x 24 mil" which is totally different product, right?
Wish I knew more. From the measurements you listed it's almost certain that the LEDs are wired in series and are getting 1amp.
It would be really nice to be able to put a knob on it to dim the light as needed. Many drivers have an adjustable current limit with a 0-5v pin or leads for a 0-5k pot. Barring that, if it's a constant current LED driver, it's got to be using some resistor to sense current. Tap a pot onto that and you're golden. Worst case, this is a steal for a lamphead with emitters, optics, and proper heatsinking. I'd buy a couple and attach my own drivers at that price.
www.recumbents.com wrote:I just received my 12-90V light today. It looks like a resistor inside the light, but it is really a thermal switch (labeled ZH KSD-9700, 250V 10A 65 degrees C). That's 150 degrees F. I think the in-line DC-DC converter is performing the current limiting duties. Mine did not even have a back on the light, so the thermal switch is in plain view. I'll post some test results later.
lazarus2405 wrote:www.recumbents.com wrote:I just received my 12-90V light today. It looks like a resistor inside the light, but it is really a thermal switch (labeled ZH KSD-9700, 250V 10A 65 degrees C). That's 150 degrees F. I think the in-line DC-DC converter is performing the current limiting duties. Mine did not even have a back on the light, so the thermal switch is in plain view. I'll post some test results later.
Thanks, that makes a lot more sense. So the driver is an actual CC LED driver - it just has a wide input range. That also means that you really can't run the light off a 12v source without the driver module.
If anyone can tell more specifically which actual LED emitters are in this thing, I'd be interested. Close-up pictures might help. Thanks.
www.recumbents.com wrote:Though I haven't actually looked at the flamethrower end of the light while it is on, it appears to have smaller LEDs between each large LED, can anyone confirm that those light up too?
johnrobholmes wrote:Here is a light I saw on another moped forum. DX special http://www.dealextreme.com/p/10w-800-lu ... 26v-101461
I hear the beam is funky and square, but for that price it is hard to beat.
NeilP wrote:I will at least try and post a beam shot of these against a know lamp
NeezyDeezy wrote:FYI geoman gear has the 1000 lm magic shine on sale this month -- it's better IMO because it ships from the US.
Good, since I have a remote switch on my recumbent bike. One more question - is it relatively white or has the bluish tint ?NeezyDeezy wrote:When it's plugged in it by default comes on high, without buttons, so depending on what you want to do a switch would work.