Beamshots and analysis added. MR16LED for "low cost" caving lamps.

I have been involved lately into MR16 and GU10 LED market and performance analysis and I can say I have been more than surprised with the results. There are out there many crappy products with poor performance -near 95% of what people can get in regular stores-. but a few of the MR16 LED ones, even with unknown brands, are getting efficiency over 90 lm/watt, which is very good when we talk about neutral and warm white lights, with a CRI over 80, reaching 85 in some of them. Its lm output is around 600 lm, which is more than we ever dreamed in the good old days of carbide lamps. They are on the 15-25€ range. (you can see a small part of my results for GU10's here)

Some high end flashlights are getting those efficiencies or higher, at the cost of cool white light and poor CRI.

All you need is to protect the driver with some epoxy potting, a good set of cables and connectors and one of those easily available LiPO or LíION batteries for R/C machines to have an incredibly bright and efficient headlamp. Of course you need also a container for the battery, but there are out there dozens of watertight ones at affordable prices.

So, basically you can get a 600 lm x 10 hours headlamp for less than 120€. I'm not saying they would be better than those high end lights... but what you get for that price is a lot... and at the end you can make you own light, which is another incentive for old fashioned cavers.


Regards,

Javier

Re:UPDATED MR16 LED for "low cost" caving lamps.

Here you are some results of high end "no brand" MR16 lamps I have developed and then modified to be used on high humidity environment.


I think they are a great starting point for a caving headlamp if you want a lot of light, and warm white.

Re: BEAMSHOTS. MR16 LED for "low cost" caving lamps.

Some beam shots comparing the MR16 LED vs a Nightcore H50. The MR16 has a near 180º spill, making it very confortable the use, on the other hand the spot is not so strong. The image on the animated GIF has been converted into B/W to notice better the light difference, but the headlight is cool white and the MR16 is warm, as you can see on the first pics.

To my opinion there's little or no difference on the light you get from both, and we can say is more than you need for caving.





There is some color temperature differences, and this is because the white balance was AUTO. The rest of settings have been fixed.


Here you are a gif to show the beam differences.

http://gifmaker.cc/PlayGIFAnimation...Puq4JGr3O0bc5G9DxBTyoP&file=output_ylK69A.gif

Re: BEAMSHOTS. MR16 LED for "low cost" caving lamps.

now remove the 4 rectifiers on the driver eliminating their drop.
i have done this to ones that were going in 12v rv fixtures.
makes them better on low batteries.

Re: BEAMSHOTS. MR16 LED for "low cost" caving lamps.

snakebite said:

now remove the 4 rectifiers on the driver eliminating their drop.
i have done this to ones that were going in 12v rv fixtures.
makes them better on low batteries.

Click to expand...

Yes, thanks for the input.

Efficiency of the driver is its weakest point, at least in the models I'm using.

At 12 Vdc is 76%, but at 24 Vdc is 88%. The LED, which is a COB designed to stand 30 Watt is clearly underdriven, that is the reason of overall the high efficiency lm/watt, has a Vf voltage of 33,8 V. In fact this MR16 was developed starting from a very good GU10, and for the GU10 having that Vf on the LED is a good thing.

Javier

Re: BEAMSHOTS. MR16 LED for "low cost" caving lamps.

Here you are one animated gif, B/W for you to notice the beam differences independently of color temperature.


http://gifmaker.cc/PlayGIFAnimation...4nRQr29DCqUH9TkFoa9T48&file=output_iE90o4.gif

Re: MR16 LED for "low cost" caving lamps.

Here you are some analysis regarding the efficiency of the boost driver on the MR16 LED analyzed. (Warm white, 60º angle, CRI 82.4)

The test was done to one lamp, which was the worst performing of the manufacturing badge. Others had 10-15% higher lm output.

Looking at this I would not recommend to use the lamps under 10 Volts... But in fact if you need to you can go lower than that. My voltage of choice for a Li-ION pack would be 14,8 Volts. but 11,1 seems good enough.

At 7 Vdc the efficiency is very poor, but still regulated... below that goes out of regulation. Not good for a 7,4 Li-ION pack. Furthermore, I don't think those watts wasted on the regulator will be any good for the life span of it.