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Dual Transistor ID help?...Breadboard tips, tricks and hacks. and SMD (oh my!)

Started by rullywowr, September 07, 2013, 02:52:20 AM

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rullywowr

Hello,

This is slightly off topic but I have been delving deeper into the world of +5v arduinos and logic circuits etc.  I saw this LED breakout board on eBay which uses SMD LEDs, SMD resistors, and a SMD transistor (dual?) of some sort.  Ideas like this are great in the fact it allows you to clean up some board space by making common "tools".  A tool like this is a big help when you just want to wire up a LED for some feedback from a MCU..rather than grabbing a LED, a 120R resistor and two jumper wires.  Seeing this and other breadboard tips on the net has inspired me to make some of my own layouts which are going great and helping while I do some prototyping in other electronics projects.  I have been doing some cool breakout boards for ATmega328s as well as some ATtiny85s....more to come soon.

Anyways, here is a link to the board I am talking about.  Check out the underneath where there is a 6 pin device (dual transistor or mosfet)?? along with two SMD 120ohm resistors.  It is pretty clear that the 120R resistors are the LED CLRs but that 6pin device is driving me bonkers trying to find what it is and where I can get one to play with.

http://www.ebay.com/itm/Modular-Buffered-4-LED-Breadboard-Prototyping-Module-Arduino-PIC-Rasberry-Pi/151115191098?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D17576%26meid%3D1109213034005786208%26pid%3D100033%26prg%3D8143%26rk%3D1%26rkt%3D4%26sd%3D151115191098%26
Here is the image to preserve this post:


I understand how the circuit works, and I am pretty sure it is NPN...just I am having trouble ID'ing the actual type of transistor it is.  I want to say its a dual NPN Mosfet but I could be way off the mark.  Any help wading through the massive amount of transistors out there would be a help.   And if I may be as bold to say that the soldering job on that is really sketchy!   :o

Basically, you connect the LED board to VCC and GND and when it gets a signal from a microcontroller, it opens the transistor and lights up the circuit.  Sounds like NPN to me since it relies on a pin "HIGH" to make it happen...but I am not familiar with a dual in the same package.

Just for kicks, here is my tiny SMD led breakout in the works (just has resistors and some SMD leds/headers).  I want it to be as small as possible.  In fact, my first revision was so small that OshPark wouldn't take it (must be 250mil x 250mil) minimum  ;D.

Bottom (resistors here):

I found these other links helpful in getting ideas on how to breadboard more efficiently as well which I want to share with you.  I found some of it I knew, but other ideas that actually were inspiring.
http://www.instructables.com/id/My-Top-Ten-Most-Useful-Breadboard-Tips-and-Tricks/
http://www.protostack.com/blog/2011/09/8-breadboard-hacks/

Thanks for checking out my post.



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