# help on making 12x7135 3 mode driver



## ma_sha1 (Apr 21, 2011)

Can someone draw some lines on the image to show how to wire the 4x7135 driver (right, no modes) as slave to the shinning beam 8x7135 driver on the left?

I want to make it 12x7135 with 3 modes. 
I've read some of the other 7135 threads, still can't figure this out.

Can I just pick one 7135 off each board & parallel wiring each of the 4 legs?
Do I need to connect all 4 legs? Is there a better way?

thanks for the help







Back side:


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## moderator007 (Apr 22, 2011)

Ma_sha1, you should only need three wires, coming from each leg of the amc7135. They are all wired in parallel. Look at the datasheet herehttp://www.micro-bridge.com/data/ADD/AMC7135.pdf. Solder each leg to a corresponding leg on the other board. Each amc7135 will put out about 350ma. They act as a variable resistor. I have wired in extra 7135 to other boards only using the three connections. I have never tried wiring in extra to the shinning beam board.

The attiny 8 pin chip should have a trace coming off to the Vdd of the 7135. Should be pin 7. That is the pwm out put for the lower modes. This leg (Vdd) is what makes each 7135 run the modes from the attiny.

You can pick up ground from the outside big tab of the 7135. Insted of try to wire it to the middle tiny pin on the 7135. What i do is connect say one wire on one 7135 and then another wire on a different 7135. So they are not so hard to solder on. It gets tight in that little space trying to solder all three on the same 7135. Make sure you wire each leg to its corresponding leg on each board. I have these drivers. If this doesnt work, let me know. I may have to try it too.

Tip: When soldering on these 7135's try to keep your soldering time as short as possible. I have overheated a few trying to remove them.


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## ma_sha1 (Apr 22, 2011)

Thanks, so the read tab is the same as the middle tab of the front 3 pins, both are ground,
for connecting ground, I only solder the rim together, don't realy need to solder the rear big tab directly.

right?


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## moderator007 (Apr 23, 2011)

Right, the outside ring on the board is ground, The 7135's outside big tab is ground and is soldered to the outside ring on the board. The middle leg is also ground. If you solder directly to the ring on the outside of the board, you can't get the driver back in the pill. It will hit the pill. Dont know if this concerns your application or not. Did you get it to work?


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## ma_sha1 (Apr 23, 2011)

Thanks, I'll get to work on it today.
I am making mag mod, so plenty room.


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## vestureofblood (Apr 23, 2011)

ma,

I use a 24x 7135 chip set in my SSt-90 (mine is 3 mode though). You may need to heat sink the chips. With only 1 slave it may not be a problem, but with the board I made the current was falling off quickly after only a minute or two of run time. Once I heat sinked the chips it became stable.


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## VegasF6 (Apr 24, 2011)

Wow, that's gotta be some kind of record!


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## ma_sha1 (Apr 24, 2011)

vestureofblood said:


> ma,
> 
> I use a 24x 7135 chip set in my SSt-90 (mine is 3 mode though). You may need to heat sink the chips. With only 1 slave it may not be a problem, but with the board I made the current was falling off quickly after only a minute or two of run time. Once I heat sinked the chips it became stable.


 

Thanks. 

That's a lots of 7125  I made a double decker, copper heat sinked the rim and potted it.
It does have 3 modes, The high is now stable 4.2A.


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## jasonck08 (Apr 24, 2011)

You should post a picture of what it looks like.


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## richpalm (Apr 24, 2011)

I sacrificed another driver for parts and piggybacked four 7135's onto the spring side of the 8 chip board. It works fine for my lights but you'd better be damned good with soldering!

I find that high, fast heat is far superior than trace-lifting slow heat that wicks through everything else before the solder will melt where you want it to-on the joint. With that high heat I'm able to put a glob of solder across all 3 pins on the donor board, it melts fast, and I lift the chip off the board at the same time. No problems yet using this removal method. A little trick I learned when I worked in defense electronics where low, slow heat was discouraged due to the damage it would cause.

Rich


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## beam24 (Oct 23, 2011)

ma_sha1 said:


> Can someone draw some lines on the image to show how to wire the 4x7135 driver (right, no modes) as slave to the shinning beam 8x7135 driver on the left?
> 
> I
> 
> ...




can someone draw the lines on the drivers, it will help me out a alot and do i solder one of the stars ? thanks


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## vestureofblood (Oct 24, 2011)

beam24 said:


> can someone draw the lines on the drivers, it will help me out a alot and do i solder one of the stars ? thanks



Hi beam,

Basically what you need to know is this. The pins on the chips have to be linked one to another. If you look at the chip with the fat single pin facing down that is the ground, the smaller pins from left to right would then be Pos, ground, neg. 







You need a wire going from the - leg of one of the chips on the main board to the slave, then a wire from one of the + legs on the main board to a + leg on the slave and then one for a ground. For ground you can use the outer gold rim of the boards, but I use the tail piece for a better connect. 

Then once that is done just wire up the main board to the battery like normal.





If you are going to use a slave replacing the factory leads with some thicker wire is a good idea.

Also when you do that in order to keep from tearing the little + LED pad off some thing I ALWAYS do is this.






I strip the + wire a little longer and solder it directly to both the + pad as well as the top end of that chip next to it. 


As for the modes and soldering stars it depends on what you want. If you have the shining beam driver the default setting is 3 mode. If you have a variant of this driver from another source its probly 5 mode by default.

If you want to change the mode group on the shiningbeam driver you will first have to unsolder the 2 legs on the controller board that are soldered together, dont detach them from the board, just get the solder out from between them.

Next take a razor knife and cut the electrical path to the board. You can see it under the green. The one you want to cut is the 3rd one. You can see its path just above it running to a hole.

Then make a solder connection from the star you want to the outer rim of the board ( I use a piece of wire) 

Star 1= Low, Mid, High,Strobe, Sos. S2= Low, High, Strobe. S3= Low, Mid, High. S4= Low, High.

Here is a picture.
http://s10.photobucket.com/albums/a102/udownload/Flashlight/?action=view&current=8x71354mode.jpg


Finally its not a must, however in most cases when using these boards with a slave/s for some reason they require heat sinking to stabilize the current. I usually make sure all the wires will lay perfectly flat so that I can stick all of the 7135 chips to a chunk of copper or aluminum.

If you are only powering the light by 1 li-ion or 3x nimh you may get by without it, but if the voltage is any higher than that you'll need it for sure, other wise at about the 1-2 min mark your current will fall like a rock.


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## las3r (Oct 25, 2011)

the drivers that i have is just like above from shining beam ,so i don't have to do anything to the stars/cut the trace to have 3 modes correct ?


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## vestureofblood (Oct 25, 2011)

correct.


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## blackron (Nov 3, 2011)

When using this method do the lead wires from the slave board get removed? Which lead wires would be used to connect to the led the slave or the master wires?
thanks


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## moderator007 (Nov 3, 2011)

In vestureofblood's first pic the red wire from the slave will go where he has drawn the black line to on the master board. The black wire from the slave will go to where he drew the red line to on the master board. Now you will need to have one more wire were the blue line is drawn. To any of the back tabs on one of the amc7135's. You don't have to connect to any particular one. Just one on each board will work. If you solder the wires coming from the slave to the master board then use the wires on the master to connect to the led. It doesnt really matter as long as the power is being connected only from the master board were the attiny13 is. Attiny13 has the modes. If it is a board without modes and no attiny13 ic then it doesnt matter which one has power.

You can use the wires already installed. As the slave is only adding 1400ma to the master threw those tiny wires. The master wires to the led will see the combined current. I usually unsolder all the wires and install 20 or 22 AWG high strand count silicone wire. The less resistance will give you more current and is more efficent. But is probably not necessary.


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## blackron (Nov 3, 2011)

Thank you for that explanation. Your help is greatly appreciated.


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## Mattaus (Mar 16, 2012)

Digging up an old thread here, hopefully someone is still watching.

Is there anyway to add the extra 7135s without using a slave board? So adding extra ICs to the original master board? Could you piggy back 7135s on top of the existing 7135s? heat sinking is obviously an issue but if you could get around that, would it work? By 'piggy back' I literally mean placing a new 7135 on top of one that is already on the board, and soldering all it's legs to the corresponding legs on the existing chip? Does that not achieve the same result more or less?


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## b-bassett (Mar 16, 2012)

iv seen plenty of ppl simply piggy back another chip onto a board will no ill effects. just be carefull not to overheat the chip whislt soldering.
also bare in mind that if your using 6V or more the chips will probably require their own heatsinking, which could be tricky with the botom one.


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## Mattaus (Mar 16, 2012)

Thanks. So literally popping a 7135 on top of another one and soldering the same pins to each other does the trick? Nice. I'm aiming for single cell usage at 4.5A so high voltage won't be an issue, though I will provide extra heat sinking regardless.


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## b-bassett (Mar 16, 2012)

i cant see any reason why it would be a problem, although i havent done it , iv seen plenty of examples.
soldering that small will be a bit triky, might be an idea to use a drop of superglue, to hold the chip in position, then solder the links.


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## Mattaus (Mar 16, 2012)

Good idea. Thankfully they're cheap enough to let you make plenty of mistakes ;-)


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## vestureofblood (Mar 17, 2012)

That piggy back thing can work. I have seen pictures of it done before. The biggest issue is stabilizing the current. In a high current situation these driver heat up fast on their own, piggy back will compound the issue. If you dont get the heat properly displaced the current of your light will fall like a rock around the 1 minute mark.

I tell ya what the whole world needs is a very highly thermally conductive potting compound. Then all our flashlight needs would be solved.

I have experimented with a few things but so far have not found anything worth shouting over. About the best gain over more traditional means I have found is JB weld with a high concentration of copper powder mixed in. This gives a marginal gain but still nothing like the 300+ w/m.k truly needed


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## Mattaus (Mar 17, 2012)

Yeah I was thinking of thermal pasting a small copper/aluminium slug on top of the added components to help with heat management. It would work on a 12x7135 board because you will have 4 points for attachment. Make it thick enough and it could do something worth while. That's my theory at least.


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