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

Relic have u tried bending the legs ? Much easier

Another suggestion that would be good on this thread is if u post how many amps the driver will be, just for say u add 3 to 8 extra chips what would the driver be at for learning perpases ?

Thanks everyone.
Nitro, I avoid bending the legs because the structure inside the chip itself is not designed to have the leads bent. The worst case is, you break off a pin. Most of the time you’ll be OK. However the stress could weaken the internal bond wire contact, leading to eventual failure. You might notice it as a flickering/varying output (intermittent) or not the current output you expected (disconnect).
For this reason, I do not recommend it. YMMV.

Thanks relic. Your tutorial is clear as a bell. A picture is worth a thousand words. I find visuals really simplify a seemingly daunting task. I know I can do this, and I will do this!
Actually, the way you don’t bother bending the pins does make sense to me. It leaves them out in the open, and more accessible to the soldering tip, while keeping it away from the chip itself.

Thanks relic for the how too. I’ve tried this a few times with no success. I guess it’s mostly due to my hands not being steady enough. I mean your photos and instructions make it sound easy. But when the driver is the size of a dime and the 7135 chips are the size of a tiny ant - and you have to solder the ant sized chips individual legs - no way for me. And I have a good mechanical ability and aptitude. But this is a no-go for me.
My poor attempts make me appreciate the fine detail work many of you on this forum can do.

thanks!!! this will be a big help for me being a first timer :slight_smile:

You’re welcome. Bending the pins does make soldering easier; if the pins stay connected to the chip.
I will do a few more of these How-To posts. The next one will be “Adding Copper Braid to Springs”. The pics are taken, I just need time for post and write-up.

If your going to do copper braids, please show me where to get some, and the proper type. Is it the same as desoldering braid?

Yes, I use desoldering braid. Easily found on eBay, Amazon, Digikey. I use one of the more expensive brands, Soder-Wick by Chemtronics. I’ll provide a link in that post.

as a new guy in this hobby II don’t really understand why you did it…yet, but I can say the tutorial shows how to it very well :slight_smile:

So if I added three chips to 3.04A driver it would become…?

Thanks Relic! Like this How to. Looking forward to your next ones!
My suggestion is to use the How to on the subject so it’s easy to search.
Like “How to Add a Copper Braid to Springs” :beer:

As posted:

:stuck_out_tongue:
In other words, increase the light output by giving the emitter more current.
Also, we rarely stop at just adding one :wink:

Not sure if these would interest people:

Those are 16x 7135 boards. 8 each side, 20mm in diameter. Each boards has a solder point for LED+, LED-, PWM and GND.

I also have 12x 7135 boards. 6 each side, 20mm in diameter. The difference is that the solder points for LED+, LED-, PWM and GND are much larger 1.5mm in diameter through holes, thus allowing for more robust wire.

Both boards were designed for a project of mine but they can be used for many things obviously. Just saw this thread and thought people might like to know stuff like this is available

- Matt

Actually, I have some desoldering braid in the mail. It’s only 1.5mm though. I thought it might come in handy to span a gap between a driver and pill. I figured I could soak it in flux, wrap it around, heat it up and add solder. Whether its a good idea or not, I don’t know…who knows.

If using the 350mA Regulator: 3 x 350mA = 1050mA, it will be 3050+1050 = 4100mA or 4.10A
If using the 380mA Regulator: 3 x 380mA = 1140mA, it will be 3050+1140 = 4190mA or 4.19A

:beer:

http://img580.imageshack.us/img580/5301/img20130129171725.jpg

Nice boards where did u get them ?

Can you stack a 380mA regulator on a 350mA regulator, or is that bad?

They're my own design. I'm waiting until my project is finished and then I plan on offering them to anyone who wants them (plus some other things that came about as a result of the work I did). I started out intending on using the 16x7135 boards but felt for my particular project they were too cramped, so redesigned them as 12x7135 boards.

I might make a separate post about them actually. I'm probably going to give the prototype 16x boards away for free (provided the 'buyer' covers postage of course). I can't remember how many I have but it's only about 12 or so.

Perfect size, that’s what I use. Plenty of current carrying capability. It’s usually got a layer of flux on it, so you might be able to skip that step.

Yes, the two types have the same pinout, no issues with mixing them.

Mattaus, those are nice boards. Great for adding a lot of chips to a project. J)

Sending a letter to Canada is $1.65, up to 50g is $2.35… the 16x ones should fit flat in an envelope. I figure they are less than 2g each. I might be interested… thinking of where I’d use them…