|Radio and Electronics (DED Philippinen, 66 p.)|
|11. ACTIVE COMPONENTS -2- / TRANSISTORS|
|11.2. CHARACTERISTICS OF TRANSISTORS|
|11.2.1 HANDLING OF CHARACTERISTICS OF TRANSISTORS|
Each transistor has a maximum power rating. Which means: this is the power which can be dissipated by it, without danger of destruction.
Therefore it is extremly important to make sure that the transistor is always operated on the safe side - which means in our field of characteristics: on the safe side of the maximum power line. For this reason it is necessary to be able to construct the maximum-power-line.
A) find in the data sheets the maximum permissible power for the transistor.
B) Calculate for various collector-emitter-voltages the permissible collector-current for this power. (The power dissipated for the input-values is so minute, that it can be neglected).
Ic = Ptot / Vce
C) Construct the Power-line by inserting the values of Ic for the different collector-emitter voltages.
The maximum powerline represents the field of application in a safe-area and a not allowed area.