My newest project, Advice needed as i lost mode selection. And comments on the project.

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DasFriek
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My newest project, Advice needed as i lost mode selection. And comments on the project.

Ill just give you a quick run down on the light so you know exactly what im dealing with and to brag about its fun factor also.

Its a black SF L2 w/ stainless accents, Just looks great with the two contrasting colors. I used a AMC7135*8+MCU 2800mAh 5-Mode from KD or Illum supply as i buy from both but they sell the same exact part. I then added an XML U2 led and on the interior side i added 2x 7135's. I also beefed up the ground parts and positive spring, I need to try an Kan-28 in the tail for better amp flow.

Im getting different tailcap readings depending on the cell as i suspect internal resistance starts being an issue over 3A's.

HiMax 2600= 3.5A      Panasonic unprotected 2900= 4.2A    BIO IMR 1400=4.6A+

The issue is when i added the second 7135 i lost control of of the modes and just get HIGH, Which isn't the worst thing but it would be nice to have lower modes to help control heat and still use the light. And yes im done many things to get thermal issues under control as much as possible.

I have the 2nd star clockwise grounded for the 3 mode use. The 7135's were placed opposite of each other internally, The first is next to the positive lead and the second directly across from it. Ive had bad luck loosing mode control before with AK-47 drivers if i used the 7135 next to the positive lead on 1560mAH drivers. The only reason i used these specific spots was my soldering iron didn't have a good enough tip to get in such tight spaces, So i bought a new 50 watt one last night with a fine tip. 

Has anyone lost modes by adding extra 7135's?

Any specific spots to piggyback the IC's that tend to cause issues? 

I know the rear of the 7135 and the middle leg is ground, But does running those to the outer circle ground have any adverse affects?

Besides this issue i have just a few spots that need improved like the solder joints on the led board being too thick from my other crap iron, Ill smooth and lower those today as its causing a large gap between the LED and reflector and loosing focus and lumen's. Despite that it will over-run my 2.8 T6 lights when placed side by side and then merging the beam.

As to the U2 led i like it alot as im a cool white guy, It seems only slightly whiter than the T6 bin. Other than that its not worth $2-$3 over the T6 imo. Ive not had it outside yet to see its throw and flood output, But I need to get the reflector fixed for a better focal point.

Inside the house wall tests show that i cant tell it apart from the beam of my Sky Ray 3800, But i know its just my eyes can pick up the higher lumen's the 3800 is putting out. But they look like twins to the naked eye tho. It still cant beat the intense hot-spot of my KD C8 tho, I love that light! 

(Edit) After reading the first sticky im gonna try and back the amp's down to around 4A as anything higher is just extra heat. I may start by removing the 7135 at the positive lead. 

 

 

 

 

Edited by: DasFriek on 08/15/2011 - 09:03
okwchin
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Is it a case of a dead MP? if it dies, it stops sending the PWM, and given the right circumstances, the current regulators just do what they do when not instructed, and thats full output.

Too much heat to the MP chip? I am not familiar with linear driver modding (never done it myself) but this is my guess atm. (based on past experiences, but not with torch drivers.) Maybe the iron wasn't fine enough, or hot enough, or the tip wasn't clean enough, or not enough break time for it to cool, so you ended up needing to apply the tip for longer, (greater than 3-5 seconds) to get the solder to flow, and thereby heating the chip enough to start killing it?

"like everyone else - I’m looking for my next “last” flashlight" -  ohnonothimagain

E1320
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I have had this happen before when adding 7135s to these drivers. Remove the extra 7135 chip and all the extra solder you added and see if the driver works normally. If it doesn't you might have fried something by overheating it during the soldering process. If it does come back to life after undoing what you did than start over adding the extra 7135s one at a time. Add one test it make sure the modes work and you get 3.1 amps on high than add another and test again making sure the modes work and you get the 3.5 amps you are trying to achieve. It is very difficult to do this mod since the parts are so small and heat sensitive. Good Luck.

I am already visualizing the duct tape over your mouth.

DasFriek
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I suspect i killed some 7135's with that old soldering gun, The list below now shows the current amps each cell is now pushing.

HiMax 2600= 3A

Panasonic 2900 = 3.4A

BIO IMR 1400= 3.7A

Thats a rather large drop in current and ive done so serious beefing up of all pathways electrons flow. I added a stronger Kan-28 tailcap, lengthened the drivers short positive lead and its wrapped in thin copper wire, Added copper wire threw the drivers pcb and connected the ground rings on both sides.

I just hope i didn't kill any board mounted 7135's and have to replace them or start over with a new driver. So im going back in none the less as i want 3 modes and 4A max and id like that on the Panasonic 2900 for the longer run times.

The new soldering iron should help as it has a fine tip and is adjustable from 20W-50W compared to my old half dieing 30W with crap tip that fused itself internally.

Looks like ill be needing another Illumination Supply order the way im going threw drivers and 7135's. Thank god the IC's are cheap and i can also scavenge them. But for this build i want to use new ones and not take the chance of soldering in old crap chips.

Ive checked all traces for shorts as i have decent vision for close up work, And since i lengthened the positive spring on the back of the driver i can actually add the 7135's back there now for more room to work.