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Topic: Should my transistor heat up THAT much with this circuit (Read 1 time) previous topic - next topic

eddiea6987

Okay now here is a picture since my schematic drawing abilities are not up to par, and by the looks of it neither are my circuit building abilities because i dont know if i am doing something wrong or if this is how things go, i know transistors dispense heat but i thought it would be when you got up there like at 24 volts or something and this transistor i thought would be more then enough and not get hot, anywho here is a picture of my connections and transistor datasheet
my goal was to make my own little H bridge on a circuit board but i cant even get passed testing out my components

oh and the code on the Arduino is simply the fade led example code that comes with the ide, and the motor does run and the code works fine  it speeds up and slows down but the transistor gets reallly really hot
http://alumni.cs.ucr.edu/~sneema/mje3055t.pdf

http://i54.tinypic.com/311kwoi.jpg
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

RuggedCircuits

I think you need to rewire. Connect +12V to the motor, other side of the motor to the Collector. Connect the Emitter to ground. Finally, add a resistor (330 ohms, 220 ohms, something around there) between pin 6 and the Base.

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The Rugged Circuits Yellowjacket: 802.11 WiFi module with ATmega328P microcontroller, only 1.6" x 1.2", bootloader

eddiea6987

Good MAN thank you! works like a charm, now perhaps a little insight as to why? And i would of figured since i was switching the transistor to the ground i would need a PNP transistors, since that for the "negative" side of things..?
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

RuggedCircuits

I'm afraid I can't summarize a semester's worth of circuit analysis  :smiley-sad-blue:  Perhaps someone else can provide a gentle introduction to the theory and operation of NPN transistors. Or maybe find some on-line resources to start learning? There are common misconceptions floating around that get in the way of actually understanding things, and you may have to "un-learn" some things first.

This site looks like it might be a good start:

http://www.4p8.com/eric.brasseur/vtranen.html

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The Ruggeduino: compatible with Arduino UNO, 24V operation, all I/O's fused and protected

eddiea6987

#4
Jul 05, 2011, 06:14 pm Last Edit: Jul 05, 2011, 06:16 pm by eddiea6987 Reason: 1
Oh i have done my share of online reading , and specially on transistors but i guess i just had it totally wrong i was using them all with the same polarity just like my picture connecting all positives to all 3 leads but then after really looking at what you told me to do,  the most obvious thing clicked  " NPN "  why would i add all of the same polarities to both N and P type material. Thanks a lot though for part taking  in my breakthrough!

This crucial moment is almost as important as the invention of the transistor it self lol, at least to me.
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

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