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Sapphires don't just come in blue

fyrstormer

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They also come in warmer colors. :D

CIMG5287b.png



This is one of my Sapphire 25s, modded with a Nichia DS Warm LED. The tint is fabulous. :) Here it is next to a stock Sapphire 25:

CIMG5284b.png



I've been carrying this for a while now, and while I'm generally not a fan of warm tints, this LED has great color rendering -- the best of any 5mm LED I've ever seen, actually. Despite how warm it is, blues actually "pop" quite well when illuminated by this light.

CIMG5186b.png



The beam is slightly narrower than stock, but it retains the exact same beam pattern.

CIMG5185.jpg



I bought these LEDs in 2010. Now I feel kinda foolish for not trying them sooner. It's pretty much perfect.
 

fyrstormer

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Also, just for fun, here's a picture of the original Nichia GS emitter running on a nearly-dead battery, making the twin emitter dies clearly visible under the phosphor coating:

CIMG5183c.png
 

eala

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I had bought a whole bunch of the LEDs from Optosupply. Minimum quantities are high so I sold most of them off. The LED is very nice. No where near as nice as the High CRI LEDs that Don offers, but it works well in the Sapphire. Less flux than the stock.

The Sapphire LE can handle up to 5V, so no problem on 10180 cells. The output remains the same so I assume the driver is a boost/buck style.

I like that the Peak Eiger stuff is compatible with the Sapphire. I prefer the Peak bodies to the stock Sapphire one.

I don have to use magnet spacers since I removed the QTC pill from the body. QTC is not compatible.

eala
 

fyrstormer

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Probably ought to start a new thread to discuss this, but I thought the Sapphire 25 driver was boost-only? You're saying it's buck-boost? May I ask where you got that information from?
 

eala

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Purely from my imagination. I thought you needed the voltage to the LED to be somewhere between 1.2 and 4.2 V which is why it was both boost and buck. Hoping Don can jump in and clarify. I am not an electrical engineer. :)

I know that the light works perfectly no matter the battery used and the light output stays the same.

eala
 

fyrstormer

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Yes, that is true, but since the Sapphire is designed to run on a 1.5V battery, the driver doesn't need to have buck functionality. It may in fact have it, though.

Odd, I started this thread to show off my super-warm emitter mod, and somehow we ended up talking about drivers.
 

McGizmo

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.... I thought you needed the voltage to the LED to be somewhere between 1.2 and 4.2 V which is why it was both boost and buck. Hoping Don can jump in and clarify. I am not an electrical engineer. :)

I know that the light works perfectly no matter the battery used and the light output stays the same.

eala

I am not an electrical engineer either but I was told that the LE could handle a range of voltage similar to what you have stated. Actually I think it was good up to 5Vin but when I asked if it would be OK then with a USB input source I was told that the Vin from the USB might have voltage spikes that could trash the converter. :shrug:
 

fyrstormer

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USB better not have voltage spikes. Computers don't tolerate voltage spikes; that's why they have big brick-like power supplies stuffed full of very large capacitors.

Have you hooked up a Sapphire 25 driver to your bench power supply to test if it produces flat output between 1-5V? If not, can you? Inquiring minds would like to know.
 

archimedes

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The typical Vf for the Nichia NSPW310DS is 3.2V (max 3.5V) according to the data sheet.

If the output from a 1.5V AAA is the same as that seen on a freshly charged 4.2V Li-Ion cell, my guess is that there is probably a buck circuit too. It is possible that the tiny 10180 might have some voltage sag under load, given its low capacity, but the drive current of 25mA is still only a fraction of its 90mAh ... under 0.3C.
 

McGizmo

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I went back and looked at my e-mails discussing this converter (back in 2009; my memory is faulty back in last month). The converter IC is rated up to 10V but other components are only good to 6.3V. The designer said that 5V USB should be fine but was concerned with some of the USB wall plug chargers which might have voltage spike. There was also some concern about noise but not elaborated on. At any rate, the light engine should be fine on 1xAAA or 2xAAA, single cell lithium primary or Li-Ion. My guess is that the IC was designed as a constant current driver probably for USB or cell phone applications and for want of a better understanding I would call it a buck/boost driver. I did confirm back then that the current to the LED did hold over a range of voltage from 1V to 5V. I suppose since we are into the details of the converter I should add that it does use a sense resistor and changing the resistor can change the output. Output current ceiling is just north of 40 mA and I was provided resistor value for a minimum of 15 mA. I don't know if the driver would be stable below 15 mA output or not. BUT, this sense resistor is really really small!!! I purchased some resistors and attempted changing them out and even with some expensive SMD soldering tweezers I killed more boards than I was successful with and came to the obvious conclusion that the sense resistor needed to be selected and installed at the time of converter manufacture. I stuck with 25 mA and refused to consider opening the door to multiple choice on output in my Sapphire offering.

These little converters are pretty cool and certainly expensive. They cost me more from the factory than the average flashlight probably retails for!
 

fyrstormer

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Ah, yes, a USB wall charger doesn't have the same strict regulation that a computer power supply has. Also, most "transformers" operate using PWM nowadays, so unless there's a capacitor in the mix to smooth the 120V spikes, there's no telling what the reaction of sensitive electronics will be.

It's good to know the driver can safely handle a Li-Ion cell. I imagine that information will inspire a few people to switch to Li-Ions to get a smaller form-factor, just because they can.

It would be cool if the sense resistor could be replaced with an adjustable resistor that can be tweaked with a jeweler's screwdriver. If the unit were standing upright instead of laying down on the board, I suspect there would be room for it under the LED. It would have to be pretty small, but if the fixed-value resistor can be so small, it must not need to handle very much power, which makes the prospect of finding a small-enough variable resistor more promising.
 

eala

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You could drop the effective resistance by adding a resistor on the side (in parallel) I think. If it is the super tiny component on the board, I am not going to try.

Glad I can continue using my mini Sapphire.

eala
 

jumpstat

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Frystormer,

The warm led of the Nichia is very interesting. I like warmer leds and the best that I have is in a PD-S. I have no idea what Seoul led is in the PD, but I imagine its the standard one but colour is fantastic and with the PD reflector, its the best beam profile IMHO. So having said that, is the Nichia beam colour like the PD-S? TIA
 
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