After months of planning and buying I have finally finished my SBT-90 build. I must say the most challenging part of the build is packaging.
Parts List:
Original switch housing - I removed the plastic bulb/led housing with a grinder to allow for the SBT-90 heat sink. (See later pics)
The switch assy. separates from the outer plastic housing above without hardware removal (just push).
The switch itself separates from the blue plastic which contains the ground screw.
In order to use the driver with the stock switch assy. I had to isolate the positive switch terminal from the battery terminal (refer to DIWdiver's schematic). The two outer contacts are bent to make contact with the push button switch, the positive terminal of the battery, & the light source. I simply straightened the side which would normally contact the positive terminal of the battery.
After placing a small amount of solder on the contact which mates to the positive terminal of the battery to ensure a good connection and carefully soldering all the wires between the LED, driver, & switch assy. I was finally ready to apply power to the LED. (It's not the best job I know.... But it was difficult to get all of this stuff to fit into such a small housing.)
The heat sink is not perfectly flush with the maglite housing but after installing the reflector and lens without the base everything fits nicely. The reflector base is used with the COTS maglite to vary the height of the lamp relative to the reflector and produce a different beam pattern.
So after the build was finally finished I charged the feilong batteries with a ultra fire WF-188. Unfortunately I fell asleep and when I woke up one battery was charged and one was not. The battery that did not charge only has a potential greater than ~3V briefly, after applying a load it drops down to 1.5V. I'm not sure if the battery was DOA or if the charger is to blame. Either way with one good battery I was able to get over 5A of current flowing through the LED.
Beam Shot
So I have now ordered two new batteries from China. Once they arrive I will post updated current measurements along with beam shots.
NEW BATTERIES HAVE ARRIVED
In order for these new unprotected batteries to make a connection with the switch assy. I had to build up a solder mound.
After a slight modification to the tail spring it was times to take some current measurements.
Over 10 amps I am most impressed!
This beam shot does not do it justice. It's really really much brighter than it appears.
There are a lot of posts on this forum regarding current measurements and how the measuring device adds significant resistance which affects the current measurement (e.g. the measured current is less because the resistance of the leads etc. are impacting the circuit). I'm not sure this is the case here (just my opinion) because I was able to measure over 10 amps of current. The meter actually started beeping and flashing I'm really surprised I didn't blow the fuse....
I wish I would have taken some pics of the light output outside it was pretty impressive. But the emitter is only rated for 9 amps of current and heated up quickly which means it didn't last long... By long I mean less than five minutes of continuous use before the emitter was toast. I had used the light in short intervals (less than a minute at a time) not allowing it to overheat but decided this was very impractical. After spending the time and money to put this build together I am disappointed that I ended up with a light which could only be used for a few seconds at a time.
Any ideas on what a practical amount of current would be to use with these types of emitters? I would think something around 5 amps would possibly be OK for extended periods of use but I have yet to do any testing. Considering the limited thermal management available due to the size of the host it's hard to say without some experimentation. I do believe the thermal management is the limiting factor with a build like this.
I think my next build I will be more conservative and focus on practical use instead of maximum lumen output.
Parts List:
- Maglite D switch assy. I bought a $50 torx set but it was no help so I finally drilled out the original switch assy. It's good the new switch assy. came with the appropriate torx driver.
- SBT-90 emitter.
- DIWdiver's IS1006-1025 driver.
- Thermal pad for the driver.
- Heat sink for the driver. I used a bench grinder to shape the aluminum (length, width, & height) to fit inside of DW's heat sink and attached DIWdiver's driver with Artic Alumina.
- DW's heat sink.
- 16mm aluminum reflector
- Feilong batterys/battery
- Battery charter
Original switch housing - I removed the plastic bulb/led housing with a grinder to allow for the SBT-90 heat sink. (See later pics)
The switch assy. separates from the outer plastic housing above without hardware removal (just push).
The switch itself separates from the blue plastic which contains the ground screw.
In order to use the driver with the stock switch assy. I had to isolate the positive switch terminal from the battery terminal (refer to DIWdiver's schematic). The two outer contacts are bent to make contact with the push button switch, the positive terminal of the battery, & the light source. I simply straightened the side which would normally contact the positive terminal of the battery.
After placing a small amount of solder on the contact which mates to the positive terminal of the battery to ensure a good connection and carefully soldering all the wires between the LED, driver, & switch assy. I was finally ready to apply power to the LED. (It's not the best job I know.... But it was difficult to get all of this stuff to fit into such a small housing.)
The heat sink is not perfectly flush with the maglite housing but after installing the reflector and lens without the base everything fits nicely. The reflector base is used with the COTS maglite to vary the height of the lamp relative to the reflector and produce a different beam pattern.
So after the build was finally finished I charged the feilong batteries with a ultra fire WF-188. Unfortunately I fell asleep and when I woke up one battery was charged and one was not. The battery that did not charge only has a potential greater than ~3V briefly, after applying a load it drops down to 1.5V. I'm not sure if the battery was DOA or if the charger is to blame. Either way with one good battery I was able to get over 5A of current flowing through the LED.
Beam Shot
So I have now ordered two new batteries from China. Once they arrive I will post updated current measurements along with beam shots.
- New batteries on order
NEW BATTERIES HAVE ARRIVED
In order for these new unprotected batteries to make a connection with the switch assy. I had to build up a solder mound.
After a slight modification to the tail spring it was times to take some current measurements.
Over 10 amps I am most impressed!
This beam shot does not do it justice. It's really really much brighter than it appears.
There are a lot of posts on this forum regarding current measurements and how the measuring device adds significant resistance which affects the current measurement (e.g. the measured current is less because the resistance of the leads etc. are impacting the circuit). I'm not sure this is the case here (just my opinion) because I was able to measure over 10 amps of current. The meter actually started beeping and flashing I'm really surprised I didn't blow the fuse....
I wish I would have taken some pics of the light output outside it was pretty impressive. But the emitter is only rated for 9 amps of current and heated up quickly which means it didn't last long... By long I mean less than five minutes of continuous use before the emitter was toast. I had used the light in short intervals (less than a minute at a time) not allowing it to overheat but decided this was very impractical. After spending the time and money to put this build together I am disappointed that I ended up with a light which could only be used for a few seconds at a time.
Any ideas on what a practical amount of current would be to use with these types of emitters? I would think something around 5 amps would possibly be OK for extended periods of use but I have yet to do any testing. Considering the limited thermal management available due to the size of the host it's hard to say without some experimentation. I do believe the thermal management is the limiting factor with a build like this.
I think my next build I will be more conservative and focus on practical use instead of maximum lumen output.
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