11.2.1.1. CONSTRUCTION OF THE STATIC-MUTUAL-CHARACTERISTICS

Even if you find in a given four-quadrant-characteristics a so called mutual-characteristics this is very often not fitting, because this characteristics is changing when collecter-emitter-voltage is changing. For this reason it is necessary to know how this characteristics can be found for each voltage you want it.

fig. 131a

A) draw a vertical line into the 1. quadrant at the collector-emitter-voltage for which you want the mutual-characteristics.

fig. 131b

B) draw horizontal lines through the points at which this vertical line is crossed over by the lines of the output-characteristics.

fig. 131c

C) Find out the values of the base current represented by the crossed over lines in the output-characteristics and mark the horizontal lines at those values of the base-current in the 2. quadrant.

fig. 131d

D) Connect all the points which you have found to get a new graph - this is the mutual characteristics for the desired collector-emitter-voltage.

fig. 131e