Solving Transistor KFY34 Switching Load Homework

Thread starter -SJ-
Start date Jun 21, 2014
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The discussion revolves around solving a homework problem involving the KFY34 transistor, which requires drawing a schematic, calculating base current (Ib), and determining circuit voltages and currents under different conditions. Participants clarify that the maximum voltage specifications initially mentioned were incorrect, and they discuss the need to calculate Ib based on the worst-case beta (h21E) values found in the datasheet, which range from 35 to 125. The importance of ensuring the transistor operates in saturation is emphasized, with recommendations to design for safety margins in Ib calculations. Additionally, there is confusion regarding the time-dependent nature of the required plots, which participants clarify should reflect the transistor's on/off states rather than actual time variations. The conversation concludes with suggestions for further reading and practical applications of the concepts discussed.

Jul 2, 2014

-SJ-

That Uce should be typical. The KFY34 transistor has Pmax=800mW, so 440mW should be fine and no additional cooling is necessary.
OK, that's it. I'll send it to my examiner to check it out and be with hopes he will accept it despite the terrible time spent at solution.

I would like to say THANK YOU REALLY VERY VERY MUCH for patient guidance in this long-suffering thread. Now, I am hopefully a bit wiser about calculations with transistor and looking forward to learn more.
Thank You.