Electronics and Electrical Engineering Revision Sheet

1. 📌 Essentials

• Diodes allow current in forward bias, block in reverse bias.
• BJT: current-controlled device with collector, base, emitter.
• FET: voltage-controlled device with high input impedance.
• Negative feedback stabil gain and reduces distortion.
• Power amplifiers classified as Class A, B AB, C based on conduction angle.
• Voltage regulators maintain constant output voltage using Zener diodes and pass transistors.
• Load line analysis finds the Q-point in BJTs.
• Small-signal models simplify AC analysis: hybrid-π for BJT, transconductance for FET.
• Efficiency of Class B amplifier ~78.5%.
• Dropout voltage: minimum voltage difference for regulation.

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