How-To: Add 7135 chips to a Driver Board (Stacking)

226 posts / 0 new
Last post
ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

Nightbird95 wrote:
ohaya wrote:
Are you all talking about the leads from my bench supply to the driver? For the positive, I’m using some short (about 12”) lead that I made using 20AWG stranded wire, connecting the power supply to the positive of the driver. I am using a switch on the negative lead, so for the negative, I have power supply => a tailcap switch => the negative ring of the driver.

I’ll try to cut down/improve the path on negative lead, and see if that makes a difference, but the reason I have the switch on there is that I had trouble getting the driver to switch to high mode.

I’m referring to the test lead wires of the DMM. I’m posting the picture of what I did:

Attached to my DMM are the test leads I made yesterday. They’re made of 1 foot long (per color) AWG 16 Automotive Wires, Alligator Clips and Banana Plugs (soldered directly to the AWG 16 wires). The pair at the left of my DMM are the stock test leads that came with it.

I have a slightly different setup. I don’t use a DMM (except for verification.

I am using a bench power supply, so I’m reading the current to the driver from the power supply display itself. For the emitter current, I have clamp meter, so no resistance on the driver-to-emitter side.

Anyway, I don’t think it’s my leads.

I tried another identical board, with original 8×7135s, and measured 3 amps (at the power supply).

I then added 2 7135s and measured 3.7 amps at the power supply.

I’m out of 7135s so I can’t add anymore. I tried harvesting one from the earlier driver, but I lost it (literally) somewhere.

I have some more coming in from FT. but those probably won’t come in until some time next week. I can try to harvest some more from the earlier board, but I’m kind of beat for now.

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 7 months 1 week ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Easiest way I’ve learned to desolder chips is to cover all 3 pins with solder and when you melt that they all soften together then slide the chip off the boards.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

tivo532
tivo532's picture
Offline
Last seen: 6 years 11 months ago
Joined: 02/21/2013 - 12:56
Posts: 597
Location: Bay Area

ohaya wrote:

I tried another identical board, with original 8×7135s, and measured 3 amps (at the power supply).
I then added 2 7135s and measured 3.7 amps at the power supply.


Are these 380s?
Beer
bibihang
bibihang's picture
Offline
Last seen: 5 days 5 hours ago
Joined: 11/10/2011 - 09:32
Posts: 2445
Location: Malaysia

Nightbird did you buy your 16 AWG wires from online store? If so do you mind letting me know where to buy this?

Also what is the banana clips?

Nightbird95
Nightbird95's picture
Offline
Last seen: 1 year 9 months ago
Joined: 01/03/2013 - 01:16
Posts: 1153
Location: N 11º 08', E 124º 37'

bibihang wrote:
Nightbird did you buy your 16 AWG wires from online store? If so do you mind letting me know where to buy this?

Also what is the banana clips?

No bibihang. I bought my AWG 16 wires from a local store. The banana plugs I used was from old test lead wires. Banana plugs are the the ends of your test lead wires that you insert into the DMM slots.

Nightbird95
Nightbird95's picture
Offline
Last seen: 1 year 9 months ago
Joined: 01/03/2013 - 01:16
Posts: 1153
Location: N 11º 08', E 124º 37'

ohaya wrote:

I have a slightly different setup. I don’t use a DMM (except for verification.

I am using a bench power supply, so I’m reading the current to the driver from the power supply display itself. For the emitter current, I have clamp meter, so no resistance on the driver-to-emitter side.

Anyway, I don’t think it’s my leads.

I tried another identical board, with original 8×7135s, and measured 3 amps (at the power supply).

I then added 2 7135s and measured 3.7 amps at the power supply.

I’m out of 7135s so I can’t add anymore. I tried harvesting one from the earlier driver, but I lost it (literally) somewhere.

I have some more coming in from FT. but those probably won’t come in until some time next week. I can try to harvest some more from the earlier board, but I’m kind of beat for now.

Then I’m afraid I don’t have the knowledge or skill yet to solve your problem with your 7135s. Smile

maxlightings
Offline
Last seen: 8 years 2 months ago
Joined: 09/01/2013 - 05:54
Posts: 8
Location: China,Mainland

Thanks ,very useful !

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

tivo532 wrote:
ohaya wrote:

I tried another identical board, with original 8×7135s, and measured 3 amps (at the power supply).
I then added 2 7135s and measured 3.7 amps at the power supply.


Are these 380s?
Beer

Sorry, I forgot to mention that both the earlier and 2nd board were 3.04A boards from IS, so they had 8×7135 (380mA versions).

The 2 7135s that that I added to the 2nd board were the 350mA 7135s.

I ran out of the 380mA 7135s earlier (and now ran out of the 350mA ones also).

EDIT: I started harvesting 7135s from the 1st board, and got the 2nd one up to 4 amps (from the bench supply), and only left it on for a second or so, but then later, when I tried to power the driver+emitter up, it doesn’t work anymore :(.

I’ll be starting to diagnose after this…

Ouchyfoot
Ouchyfoot's picture
Offline
Last seen: 8 months 4 weeks ago
Joined: 09/01/2012 - 06:15
Posts: 5089
Location: Canada

Something I’ve been wondering about. I’ve been reading how everyone keeps getting higher current reading from their DMMs by upgrading to shorter, thicker wire. Wouldn’t the truest reading of your drivers output be if you were using leads of the exact same gauge as those on the driver and emitter wires?

tivo532
tivo532's picture
Offline
Last seen: 6 years 11 months ago
Joined: 02/21/2013 - 12:56
Posts: 597
Location: Bay Area
Ouchyfoot wrote:
Something I’ve been wondering about. I’ve been reading how everyone keeps getting higher current reading from their DMMs by upgrading to shorter, thicker wire. Wouldn’t the truest reading of your drivers output be if you were using leads of the exact same gauge as those on the driver and emitter wires?

Ouchy, see this related post.
Testing using the best possible setup will give you an idea on what current your driver can deliver. If you’re not getting the expected current then it must be something else (battery, switch, wires, heat …). Beer

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

ohaya wrote:
tivo532 wrote:
ohaya wrote:

I tried another identical board, with original 8×7135s, and measured 3 amps (at the power supply).
I then added 2 7135s and measured 3.7 amps at the power supply.


Are these 380s?
Beer

Sorry, I forgot to mention that both the earlier and 2nd board were 3.04A boards from IS, so they had 8×7135 (380mA versions).

The 2 7135s that that I added to the 2nd board were the 350mA 7135s.

I ran out of the 380mA 7135s earlier (and now ran out of the 350mA ones also).

EDIT: I started harvesting 7135s from the 1st board, and got the 2nd one up to 4 amps (from the bench supply), and only left it on for a second or so, but then later, when I tried to power the driver+emitter up, it doesn’t work anymore :(.

I’ll be starting to diagnose after this…

Hi,

So, I’ve visually inspected the board very carefully, both top and bottom, and I don’t see anything wrong. No solder bridges, no missing joints. Everything looked ok.

Putting the driver on the power supply, I am measure correct voltage when measuring voltage across the negative ring on the spring side and the + on the board.

When I apply power, and measure across the emitter, it’s showing like 0 – 0.02V.

The driver board appears to be dead, but I’m not sure what else to check?

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 7 months 1 week ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Need pics to spot a problem. Otherwise can only assume toast. If the mcu is fried you can jumper from led+ to any Vdd pin and have a single mode regulated (high) board.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
Rufusbduck wrote:
Need pics to spot a problem. Otherwise can only assume toast. If the mcu is fried you can jumper from led+ to any Vdd pin and have a single mode regulated (high) board.

I realized that I should try to ohm between the Vdd pins and OUT and between Vdd and GND, etc., so see if I can find a short.

I’ll post some pics after that, but I don’t see any “blistered” chips, etc.

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
ohaya wrote:
Rufusbduck wrote:
Need pics to spot a problem. Otherwise can only assume toast. If the mcu is fried you can jumper from led+ to any Vdd pin and have a single mode regulated (high) board.

I realized that I should try to ohm between the Vdd pins and OUT and between Vdd and GND, etc., so see if I can find a short.

I’ll post some pics after that, but I don’t see any “blistered” chips, etc.

Hi,

I’ve been doing the above testing, and connections all appear to ohm out all right.

However, what I’m finding is that the Vdd pin of the AMC7135 chips, which are all tied together, are at 0V all the time, even when I have the board powered up from my bench supply. The Vdd pins appear to be coming from pin 6 of the MCU, so presumably that is how the MCU controls whether or not to drive current to the emitter, so it’s looking like the MCU is dead?

EDIT: Pics as requested:

Nightbird95
Nightbird95's picture
Offline
Last seen: 1 year 9 months ago
Joined: 01/03/2013 - 01:16
Posts: 1153
Location: N 11º 08', E 124º 37'

Your AMC7135 chips in the bottom picture look either deep fried or grilled. Shocked

That could be the problem. Smile

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 7 months 1 week ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Power to the mcu goes through the reverse polarity diode next to led+(red wire). Check voltage there as well. If that’s ok then yes, the mcu is fried. Try a bit less flux or clean it off as it can block test leads from making good contact.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
Rufusbduck wrote:
Power to the mcu goes through the reverse polarity diode next to led+(red wire). Check voltage there as well. If that’s ok then yes, the mcu is fried. Try a bit less flux or clean it off as it can block test leads from making good contact.

Rufus,

Did you mean the component I circled in red in the pic in the earlier post (I modified the pic)?

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

Nightbird95 wrote:
Your AMC7135 chips in the bottom picture look either deep fried or grilled. Shocked

That could be the problem. Smile

Hi,

I think it’s flux – I’ll clean it up and post a new pic after I check the voltage Rufus suggested.

Nightbird95
Nightbird95's picture
Offline
Last seen: 1 year 9 months ago
Joined: 01/03/2013 - 01:16
Posts: 1153
Location: N 11º 08', E 124º 37'

ohaya wrote:
Nightbird95 wrote:
Your AMC7135 chips in the bottom picture look either deep fried or grilled. Shocked

That could be the problem. Smile

Hi,

I think it’s flux – I’ll clean it up and post a new pic after I check the voltage Rufus suggested.

I see. I thought it became that way because of the heat from your soldering iron. :bigsmile:

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
ohaya wrote:
Rufusbduck wrote:
Power to the mcu goes through the reverse polarity diode next to led+(red wire). Check voltage there as well. If that’s ok then yes, the mcu is fried. Try a bit less flux or clean it off as it can block test leads from making good contact.

Rufus,

Did you mean the component I circled in red in the pic in the earlier post (I modified the pic)?

Hi,

If it is the component I circled, then the end nearest the red emitter lead is showing input voltage (e.g., if the power supply is 3.65V, then I see 3.65V at the end of the diode nearest the red lead).

The other end of the diode shows 0V.

The markings on the diode has “||| S4” with the “|||” (3 lines) away from the at the end of the diode that is away from the red lead.

Is that diode bad then?

I can try to harvest the same diode from another board?

Or, can I just short across that diode, just to see if the driver starts working again, and then harvest/replace the diode?

Helios-
Helios-'s picture
Offline
Last seen: 1 year 12 months ago
Joined: 01/18/2012 - 21:12
Posts: 2099

Short the diode to test your mcu.
If it works then replace the diode for actuate low voltage detection (presuming the mcu is programed for that). As long as you don’t use batteries over ~4.2v and don’t care about low voltage detection or reverse polarity protection it will be fine bypassing the diode.


Counterfeit 18650s, 2,<a href=“http://

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
Helios- wrote:
Short the diode to test your mcu.

Ok, I’ll try that, but one thing I don’t understand. Is the zener diode in SERIES with the input voltage, i.e., is it like this:

Input+ > zener anode ——-> zener cathod > MCU pin 8

??

Is the zener for reverse polarity protection? If so, shouldn’t it be in PARALLEL with the input, rather than in SERIES?

EDIT: This is like going down a rat-hole :(.

I shorted across the zener, but I did that my bench supply voltage dropped to 0V.

So, I did some more checking, and it looks like MCU pin 4 (GND) is shorted to MCU pin 8 (Vcc)!!

EDIT 2: I am about ready to give up on this board. Things are really messed up.

I compared this board to another board (that kind of works, powers up, at least), and:

- I removed the diode completely from this board, and EVEN THEN, the MCU pins 4 and 8 are shorted to ground!!

- Poking around, I found that on this board, the “bottom” end of resistors R1 and R2 are both tied to MCU pin 8, whereas on the other, semi-working board, only R2 is tied to MCU pin 8.

I guess that if there was a complete circuit diagram of the board, maybe there’d be a chance to figure out where the short might be, but w/o a diagram, it’s really tough, because the vias run under some chips, etc. and I can’t figure out what’s going where :(!!

EDIT 3: Found this from an old post from relic:

http://s87.photobucket.com/user/relic38/media/Misc/NANJG105Csch_zps8dbde...

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 7 months 1 week ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

I would jumper across the diode to see if it’s the problem just be sure your polarity is correct. The voltage drop across the diode should be .6V, from the output of the diode to gnd (across the mcu) should be Vb – .6V. Vdd on the mcu is connected to the 7135 closest to the red wire via the pin on the 7135 that is closest to the red wire so a bit of solder is all it takes to bypass the mcu(common problem when adding new led+ )wire. That bit of solder should convert a non functioning multi mode driver into a functional single mode driver if the processor is the problem. If its the processor and not the diode you can use the diode as the jumper and maintain reverse polarity protection for the 7135’s.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US
Rufusbduck wrote:
I would jumper across the diode to see if it’s the problem just be sure your polarity is correct. The voltage drop across the diode should be .6V, from the output of the diode to gnd (across the mcu) should be Vb – .6V. Vdd on the mcu is connected to the 7135 closest to the red wire via the pin on the 7135 that is closest to the red wire so a bit of solder is all it takes to bypass the mcu(common problem when adding new led+ )wire. That bit of solder should convert a non functioning multi mode driver into a functional single mode driver if the processor is the problem. If its the processor and not the diode you can use the diode as the jumper and maintain reverse polarity protection for the 7135’s.

Hi,

Thanks for sticking with me.

I did jumper the diode, but then, I found the problem that was causing the ground… somewhere else, naturally.

It was actually on the OTHER side of the PCB.

Earlier, I had grounded the 4th star, to get just 2 modes. Then, when I was testing, I soldered a wire to the ground ring so that I could attach my power supply, so I just soldered that wire across from the ground ring to the 4th star.

HOWEVER, I hadn’t noticed that the bare part of the wire was too long :(, and it was touching the small cap that’s on that side of the board.

If you look at relic’s circuit diagram, that cap is going to GROUND, so it was causing the Vcc of the MCU to be grounded!!

I re-solder my test wire, and then VOILA – I got light, and LOTS of it…. With the 11 380mA 7135s, I measure slightly more than 4000mA from my power supply!

COOL!!

Probably what happened earlier was that that lead was on there but not touching the cap, and when I moved the board around, it must’ve pushed the lead to touch the cap, causing the ground :(…

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 7 months 1 week ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Good job. Way to stick with it.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

Nightbird95
Nightbird95's picture
Offline
Last seen: 1 year 9 months ago
Joined: 01/03/2013 - 01:16
Posts: 1153
Location: N 11º 08', E 124º 37'

Thats great Ohaya! Beer

A good thing to note for all us newbies who might encounter the same thing in one of our future mods. Smile

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

Nightbird95 wrote:
Thats great Ohaya! Beer

A good thing to note for all us newbies who might encounter the same thing in one of our future mods. Smile

Rufus and Nightbird,

Believe me, it’s a relief. I was starting to think that there was something inherently wrong about the 7135 mods, but really, shorting that diode, and also, that old hand-drawn diagram from relic that I linked in post #202 was what did the tricks. Once both of those were in place, it was more eliminating the possibilities and tracking down the short (which wasn’t exactly in the most obvious place).

Now that I have this one board working with the additional 7135s, which was more of an experiment to test things out for myself, I’ll feel a lot better doing stacking mods for other lights.

Thanks!

Jim

tivo532
tivo532's picture
Offline
Last seen: 6 years 11 months ago
Joined: 02/21/2013 - 12:56
Posts: 597
Location: Bay Area

ohaya wrote:
that old hand-drawn diagram from relic that I linked in post #202 was what did the tricks. Once both of those were in place, it was more eliminating the possibilities and tracking down the short (which wasn’t exactly in the most obvious place).

Jim

Yup! That schematic also helped me in understanding the driver. That’s the one I use on my DIY driver.
It would be great if we have a database of schematics for each driver! Beer

ohaya
Offline
Last seen: 3 years 7 months ago
Joined: 03/16/2013 - 19:01
Posts: 5337
Location: US

Hi,

A new, related question:

On this last board, I decided to stack the 7135s on the spring side of the board, whereas on an earlier board, I had stacked the 7135s on the non-spring side.

I know that I need to remove the small original spring and put another, conical one, inverted, instead.

This driver is going into an Ultrafire S5, which is a small tube-style 18650 light:

http://budgetlightforum.com/node/23298

The way that the head is arranged, originally, there was a reflector, a tiny pill with the emitter and driver, and that slid into the head. There was small circular wire ring that goes behind the driver, and then a retaining ring screws in behind all of that and pushes everything up to the front of the light.

When the retaining ring is screwed in, it touches that circular wire ring, which then contacts the outer ground ring, and that’s ow the path to ground is made.

In my case, I replaced the reflector and emitter with a 3up optic and a 3up star with 3xXP-G2 emitters and the 7135 based driver.

The thing is, with 7135s stacked on the spring side, when the retaining ring is screwed in, the 1st thing (and only thing, really) that it presses against are the 7135s, so it never gets to touch the ground ring on the spring side of the driver :(!

So, in this situation, how can I get the retaining ring to contact the ground ring/negative on the spring side of the board?

What would/do you guys do in this kind of situation?

Thanks,
Jim

EDIT: I kind of gave up on this driver (with 7135s stacked on the spring side) with this light. I found another problem, where the spring would bend over and touch the retaining ring, causing a straight short from battery positive to battery negative, so I think that the driver is not safe in this light.

So, I added a 4th 7135 to the 1st board, and put that into the light, and it’s ok now. The 1st board now has 4 7135 (380mA) on the pill side, and one of the “partition boards” from FT soldered to the original tiny spring, and then a spring on the other side of the partition board for the battery +.

RMM
RMM's picture
Offline
Last seen: 1 year 9 months ago
Joined: 07/23/2013 - 13:47
Posts: 4006
Location: USA

Thought I would add my 2 cents.  After adding way too many 7135s this past week (almost 100), I've found that soldering on the first piggybacked chip gets really easy after a while.  Get it lined up, touch iron to 7135 on board for about 1 second, touch pin on piggybacked 7135 and drag up.  

Where it was a lot harder was doing the double stacked 7135s... I couldn't figure out why sometimes I could get it to bridge while other times I couldn't, and it seemed like the more I did the worse I was getting!  On one board I got so frustrated that I had to just walk away from it for a while.  I tried three different types of solder... more flux... nothing was working.  Well, turns out that what I needed to do was walk away from it for a while!  The key is not letting the 7135s get too hot; if they don't suck out enough heat fast enough you can't bridge the gap.  So when I was getting more practice and working faster I was actually working against myself.  Now I start multiple 7135s and move around the board when I'm double stacking so that the next pin/chip has cooled down when I come back to it to bridge the next pin.  

Hope that makes sense... you all probably know this stuff and it made total sense to me after I realized what was going on but I just thought I would share.  

Mountain Electronics : batteries, Noctigon, and much more! What's new? 

Pages