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Electronics => Beginners => Topic started by: brendan-petrol on May 29, 2012, 10:10:37 am

Title: Reading datasheets (transistors, specifically)
Post by: brendan-petrol on May 29, 2012, 10:10:37 am
Hello,

I am trying to make a high gain - run a 1-2A load off a 74HC595 - multi-channel driver board with 5v logic and 12v supply for the load. I have a heap of 2N2222 transistors, and a few 2n3055s floating around from other projects - kits mainly, but I still have trouble reading datasheets.

Would someone be able to point me in the direction of a good resource to help me learn how to read the datasheets so I don't try to overload the transistors?

Thanks,
Brendan
Title: Re: Reading datasheets (transistors, specifically)
Post by: deephaven on May 29, 2012, 11:46:22 am
This is quite a good document for explaining it all: http://webtools.delmarlearning.com/sample_chapters/04.pdf (http://webtools.delmarlearning.com/sample_chapters/04.pdf)
Title: Re: Reading datasheets (transistors, specifically)
Post by: brendan-petrol on May 29, 2012, 12:26:58 pm
Ahh, that's fantastic!

That PDF is going straight on my Kindle. Does anyone have any other tips for good books to use to learn electronics (I think mostly my tinkering has been luck... I don't know how much of it has actually worked due to real "skill"!
Title: Re: Reading datasheets (transistors, specifically)
Post by: T4P on May 29, 2012, 12:38:49 pm
It was a lot of blood(No kidding!) and sweat and smoke but i eventually knew how to properly "decode" a datasheet.
Yes it was effort paid off and another gate opened.
Title: Re: Reading datasheets (transistors, specifically)
Post by: TerminalJack505 on May 29, 2012, 01:57:23 pm
An oldie but a goodie...

GE - Transistor Manual 1964 (http://www.introni.it/pdf/GE%20-%20Transistor%20Manual%201964.pdf)
Title: Re: Reading datasheets (transistors, specifically)
Post by: brendan-petrol on May 30, 2012, 01:22:28 am
I wonder if there would ever be a blog post on decoding datasheets!
Title: Re: Reading datasheets (transistors, specifically)
Post by: brendan-petrol on May 30, 2012, 04:30:28 am
OK, Now that I've learnt a heap about reading datasheets (thanks for that you guys!) it's made me understand a whole lot of the detail about the 2n2222, enough to know that I will have to use the 2n2222 to drive a higher power transistor. Would the 2n3055 be suitable? I want to run PWM through them - 2A max.

I have read about Darlington transistors (that is what this would be, right?) and it says that they switch much slower. Is there a number associated to "much"? I also read that a base-emitter resistor on the second transistor can speed up the switching speed. Would a Darlington transistor made up of a 2n2222 and a 2n3055 with a base-emitter resistor on the 2n3055 be suitable to PWM through?

If so, how would I pick the base-emitter resistor?

I am going to feel like a complete idiot if that is in that first PDF linked to, I am about halfway through it.