gary36
Full Member level 4
Just bread boarded 4N35 circuit. Input side 5V, 330R on anode. Cathode side grounded. On transistor side, collector connected to +24V. Emitter connected to 10K resistor to ground. Everything works fine. The output is 24-VCEsat. If I now connect base terminal to 100K and ground it. The voltage across emitter is 4V and not 24-VCEsat as expected. It goes into linear region. If I keep increasing RB, the voltage across emitter keeps building up.I guess, RB is a speed up capacitor. Why does it behave this way?