In the Home Depot deal alert thread I posted the current deal on this bulb. Normally it’s $30 but it is now on clearance at many HD’s for $7.53.
Here are the specs.
With all the junky MR16’s I have seen from EBay and the many popular vendors online, it is good to see one of good quality. Problem is that up until this clearance, this light was too pricey to consider. At least for me.
Six emitters and good quality heat sinking. The optics are screwed to the star.
The back of the bulb, the sink is of aluminum and the plug almost feels like some sort of ceramic. All this because this bulb gets really hot.
The lens is off, you can see the threaded hole in the center of the star where it is screwed to. Also the star is screwed to the sink with the proper amount of thermal compound between the 2. I don’t see this kind of quality in the EBay and vendor lights. This is done right.
Back of the lens.
I want to use one of these bulbs as a drop in for an 18V drill pack light. Most of these MR16’s can run on 12-24V but I wanted to check to be sure on this one. On others that run on voltages above 12V, as the voltage is increased above 12V, the current into the bulb decreases. This one is a little different
Here is the test set up. The 6 emitters on the star are wired in series.
The meter on the left is measuring the current into the back of the bulb.
The meter in the center is measuring the voltage at the back of the bulb.
The meter on the right is measuring the voltage across the 6 emitters on the star.
Voltage to the bulb is 12V as per spec.
Notice that as the voltage is increased to the bulb, the input current does not increase by much and the voltage on the star increases until it reaches 18.5, then holds steady.
I must point out that as the voltage is increased above 12V, this bulb shines noticeably brighter, perhaps 50-100%. Too bad I don’t have a way to measure the lumen output.
I didn’t want to go any higher than the 22.6V. At this point I think the driver is taking the hit on the extra energy flowing into the light. Notice that the input current didn’t go down as with other drivers.
Anyway, I think this is a very fine light and if any one can use this type of light or can mod it, now is the time to pick one up.
Does anybody know what emitters are in this light? Here is a couple of closeups
Most of the Ecosmart bulbs are (were?) made by Lighting Science Group. LSG bulbs were OEM’d to Sylvania, Westinghouse, and several other big name companies.
I wonder how these would survive running in 12VDC automotive systems (up to 14.9VDC with engine running in some) One of these mounted inside the hood might make for a great engine compartment light… or a pair in the trunk. These look like a steal for the price.
Main caution I learned about LEDs in autos is — don’t have them powered when starting/stopping the engine, as the electrical system gets some really astonishing brief voltage spikes. That was a few years ago.
How about 20 of these, or more, in a sealed enclosure with active cooling for a light bar?
Running at 14.4V I would estimate around 12,000 lumen. About $150 for the bulbs.
I need to run one more test, current through the emitters at the various voltages.
Thanks, for this. I at first found it hard to believe that they were XT-E’s even though they looked like them. From the spec sheets, XT-E’s will emit around 250 lumen each when driven at 700 mA! There are 6 in series. As I mentioned in the OP, as the voltage applied goes over 12V, this light shines a lot brighter. After supper I will hook up a 4th meter and measure the current thru the emitters. It’s possible this bulb will put out over 1000 lumen at higher current levels. Question is, how much can it stand.
3.45mm = XT-E
You were right all along!
A single XT-E can be driven to over 500 lumen at 1500 mA, this bulb has 6!
I added a 4th meter and took readings again of increasing voltages to the input of the bulb.
Meter on the left measures input current
Meter left of center measures input voltage
Meter to right of center measures voltage to emitters
Meter on right measures current through the emitters.
Power supply is set at it’s lowest setting, 1.3V
This is the voltage at which the emitters start conducting current.
12V, what this bulb is spec’d for
14.4V, what this bulb is likely to see in an automotive application.
The emitter voltages are a little higher for each input voltage because the voltage drop across the meter reading the emitter current is also in there.
This is the chart for the XT-E per emitter, there are 6. It is possible at the higher current draws this bulb does better than 1000 lumens
XT-E's, cool. I imagine that this emitter may be not in the top bins due to 3000K tint and 80CRI.
Wouldn't these emitters be good for AA and AA lights due to the lower Vf? Plus nice tint for close proximity lighting.
Oh, I wonder if these guys would be able to handle real high amps on copper. I've been having trouble getting high current for single cell 18650/26650 lights with XP-G2's due to their high Vf. Wouldn't it be great if these guys to take DD on a single cell and achieve higher current levels too?
It looks like the driver is a boost driver. Is it potted or can you get to the guts of it?
Your numbers are probably off by a little bit due to lead-lengths on your meters. You are showing .46A at 3.06V/emitter. According to the Cree spec for XT-E, it should be about 2.85V @ 500ma. Conservative estimate not knowing the exact emitter should be about 150 lumens per emitter at 12Vin.
Yes you are right, I had mentioned earlier that I knew I was measuring the voltage across both the emitters and the meter measuring the current flow. Those measurements would therefore measure both the voltage drop across the emitters and the meter. They were off, too high. Here is a shot of the corrected set up.
I want to use one of these bulbs as a drop in for an 18V drill pack light. Most of these MR16’s can run on 12-24V but I wanted to check to be sure on this one. On others that run on voltages above 12V, as the voltage is increased above 12V, the current into the bulb decreases. This one is a little different
