The output voltage will now decrease. Less outputcurrent is now required to keep VAand VR2at alevel sufficient to bias Q3 on since the voltage at its emitter has the tendency to decrease faster than thatat its base. The output current will continue to “foldback” as the output voltage decreases, until an outputshort circuit current level (ISC) is reached when the output voltage is zero. The resulting outputcurrent–voltage characteristic is shown in Figure 4–5B. The values for R1, R2, and RSC(neglecting basecurrent of Q3) are given by
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