Mod Summary:
- Host - One of those 12 emitter lights with the 9xmm head and 2S3P cells.
- Emitters - 6 Nichia 219C's and 6 219A's
- Wired in 2S6P configuration. Each 2S has one 219A and one 219C.
- The 219A's were used primarily to decrease current on high by increasing Vf
- Driver - 20mm DD+7135 on OSH Park board designed by wight
- Attiny 45V
- FW - Tom E's highly modified Star Momentary for the Attiny25
- LM29xx for very low parasitic drain
- Stacked one 7135
- Side Switch added
- Tail Cap converted to twisty
Pulls a little over 21 amps (3.5amps per emitter) at the tail on almost fully charged SDI INR18650-20R's. Measured a little north of 100kCd of throw on almost fully charged cells. I sure would like to know what the current and throw would have been with 12 219C's.
Background:
I've been wanting to make my wife a Trustfire 12X (Just made that name up) ever since I saw RaceR86's Retard light. It needs to be much tamer though since she seems to only believe in using the highest mode. She also just doesn't need that much light.
Enter the Nichia 219C. RMM has a great special going on them right now here. Not only will it put out a great tint with very good CRI, it should provide a nice balance of flood and throw due to it's smaller die size. I always felt these multiemitter lights were too floody with the XML.
Great emitter. But with its low Vf, it would be way too much output and heat in a 2S DD config. I don't want to use PWM to tame it down. So I'm turning to one of it's ancestors for help. Each 2S string will have one 219C and one 219A. The high Vf of the 219A will bring down the current quite a bit. I'm hoping this is the ticket to bring enough sanity to the light, but still keep it fun. My wife likes cooler tints, but the 219A's will be pretty dim compared to the 219C's. So our good relationship should continue. :)
Mod Details:
Made a couple copper disks (from old copper pipe) to put under the emitter shelf. I used 2 so that middle section of the head clamps down on them. This should help move heat down the head faster. Sanded some of the anno off (not shown in pic) mostly to get the surface flat and reflowed the disks into the head. Drilled and chamfered 4 holes to allow 3 22ga silicone wires each.
Sanded the top of the emitter shelf flat. It was quite ridgy stock. Also drilled a hole in the middle section of the head to install a side switch. The hole for the side switch wire angled to enter just under the driver shelf.
The reflector islolation rings seemed like they would block some light. Used a drill to open them up at the top a bit and to shorten just a tad.
Put all the emitters on the reflector in the positions needed for wiring. Then used masking tape to "lock" them in position. There is the emitter wiring diagram and how the A's and C's will be laid out. Then removed the emitters from the reflector and taped the top of the MCPCB's. Then I removed the tape from the bottom of the MCPCB's and reflowed onto a copper disk that will rest on the top of the emitter shelf.
Disk in head and with reflector and lens for test fitting purposes.
Kind of screwed up the layout when I reflowed. So wire routing was a bit messy. 22ga.
22ga to 20ga to 18ga. Overkill
Driver. More info on it here. Driver adapter ring made from copper sheet. This will bring heat to the driver faster for thermal monitoring. Positive wire run straight to emitters. Spring powers driver.
Momentary side switch components. One side of the switch pins were reflowed to the copper disk. One of the pins on the other side was cut off and the other pin was soldered to a wire to run to the driver. The copper disk is a slight press fit in the head and provides the Ground connection for the switch.
Kapton tape used to isolate the pins on one side of the switch. Made a make shift temporary plunger until I decide what to do for a permanent plunger.
Temporary plunger (1/4" ball bearing) held by rubber band.
I like to have each parallel bank of cells connected so they can balance voltage with each other. Cut out a clover leaf from copper sheet and punched indentations for each cell. Used lead free solder to make bumps on each side drilled a hold for also using the part to measure tail cap current.
Set up to measure tail cap current.
Tailcap twisty lock out. Machined off annodized finish. Cut copper disk. Use tooth pick to create insulated guides.
Three short 3/8" diameter copper tubing pieces cut. They are what the cells will make contact with, but springs added just in case. Plastic cap cut to height needed to press copper plate against battery tube when tail cap is fully screwed down. A slight loosening of cap locks out light. I learned this mod from DBSAR.
A few beam shots
Conclusion:
Pretty nice light. Really nice tint and balanced beam pattern. I think reds are a little more pronounced compared to my 219C single emitter lights, but the difference seem slight. Because of that, I'm second guessing my decision to use 219A's for half the emitters. I did it to tame down the light, but the efficiency hit bothers me. I wouldn't mind the reduced efficiency if it the tint improved enough. I would have to see a similar light with only 219C's in a side-by-side comparison to know if the tint difference is worth it. I have plans to make some because these 219C emitters rock. So I should be able to report back on the difference at some point in the future.
). Then test your 219C with the same DMM. That should give you a nice real world feel for difference in efficiency.
