LED_ASAP
Enlightened
Inova X1 is just like its big X5 brother---well built, and as strong as a tank.
However, the tiny single 5mm Nichia is just not powerful enough and not white enough for our flasholics /ubbthreads/images/graemlins/grin.gif
So, time for a serious upgrade /ubbthreads/images/graemlins/icon15.gif
First, the light was disassembled by our famous freeze-and-pop method.
When I looked at the converter board, I was happy to find that it was actually a well built ZLT circuit, and the parts selection was quite respectable.
There are a few things that need to be changed before pushing the board for higher current output:
1)The board does not have an input capacitor. While this is certainly OK for a low-power unit like the stock X1, it is unacceptable for a high-power light, because the extra resistance in the ground path will seriously limit the maximum current, lower the efficiency of the board, and set off lots of RF emission.
2) The output cap is too small. From the size of the capacitor, I guess it's no more than the 2.2uF minimum requirement suggested in the Zetex datasheet.
Luckily there is lots of extra space on the board, so I added an extra 10uF output capacitor, and added an input capacitor (two 10uF in parallel).
The sense resistor was reduced from the stock 0.39ohm to 0.022ohm. One could also just use a "loop" of magnet wire as the sense resistor.
A TWOL Lux III (yes, that's my prize from the Class 4 entry) was mounted on a crude brass heat sink---3 brass washers were soldered together with two holes drilled through them for the leads. The OD of the washers was reduced by grinding until it fit the ID of the brass part in the X1 head. I used a spring with ~12mm diameter to push the LS assembly against the reflector (see below).
The optic solution was a big headache. I couldn't find a 12mm diameter reflector, and when I ground a NX05 down to 12mm, the centre lens fell out, and the stock cover lens (a magnifying glass) only magnified the empty hole in the middle, instead of the yellow phosphor. Eventually I used something the size of a Mag Solitaire reflector, and let the stock reflector push it down against the LS assembly.
The spring for the (+) battery contact has too much resistance, so a bypass wire was soldered across it.
I cheated a little in the re-assembly: Instead of using a true press-fit (which I don't have the tools to do), I simply enlarged the opening of the battery tube by scraping and sanding, and added a little bit of epoxy when doing the final assembling. It worked out well.
Now fire it up (against a stock Arc AAA)
The modded X1 has ~500mA battery draw, which translates to ~150mA through the LS. The beam pretty much retained the "spotlight" pattern of the stock X1, which means you get a round, bright, almost even beam, with a small amount of side spill. The brightness isn't bad for its size and power level. I find the light very useful, and the solid construction of the Inova light certainly adds a sense of durability to the light.
However, the tiny single 5mm Nichia is just not powerful enough and not white enough for our flasholics /ubbthreads/images/graemlins/grin.gif
So, time for a serious upgrade /ubbthreads/images/graemlins/icon15.gif
First, the light was disassembled by our famous freeze-and-pop method.
When I looked at the converter board, I was happy to find that it was actually a well built ZLT circuit, and the parts selection was quite respectable.
There are a few things that need to be changed before pushing the board for higher current output:
1)The board does not have an input capacitor. While this is certainly OK for a low-power unit like the stock X1, it is unacceptable for a high-power light, because the extra resistance in the ground path will seriously limit the maximum current, lower the efficiency of the board, and set off lots of RF emission.
2) The output cap is too small. From the size of the capacitor, I guess it's no more than the 2.2uF minimum requirement suggested in the Zetex datasheet.
Luckily there is lots of extra space on the board, so I added an extra 10uF output capacitor, and added an input capacitor (two 10uF in parallel).
The sense resistor was reduced from the stock 0.39ohm to 0.022ohm. One could also just use a "loop" of magnet wire as the sense resistor.
A TWOL Lux III (yes, that's my prize from the Class 4 entry) was mounted on a crude brass heat sink---3 brass washers were soldered together with two holes drilled through them for the leads. The OD of the washers was reduced by grinding until it fit the ID of the brass part in the X1 head. I used a spring with ~12mm diameter to push the LS assembly against the reflector (see below).
The optic solution was a big headache. I couldn't find a 12mm diameter reflector, and when I ground a NX05 down to 12mm, the centre lens fell out, and the stock cover lens (a magnifying glass) only magnified the empty hole in the middle, instead of the yellow phosphor. Eventually I used something the size of a Mag Solitaire reflector, and let the stock reflector push it down against the LS assembly.
The spring for the (+) battery contact has too much resistance, so a bypass wire was soldered across it.
I cheated a little in the re-assembly: Instead of using a true press-fit (which I don't have the tools to do), I simply enlarged the opening of the battery tube by scraping and sanding, and added a little bit of epoxy when doing the final assembling. It worked out well.
Now fire it up (against a stock Arc AAA)
The modded X1 has ~500mA battery draw, which translates to ~150mA through the LS. The beam pretty much retained the "spotlight" pattern of the stock X1, which means you get a round, bright, almost even beam, with a small amount of side spill. The brightness isn't bad for its size and power level. I find the light very useful, and the solid construction of the Inova light certainly adds a sense of durability to the light.
