// find resistances to fit in the given VDB design // Electronic Principles // By Albert Malvino , David Bates // Seventh Edition // The McGraw-Hill Companies // Example 8-4, page 269 clear;clc; close; // Given data // 2N3904 Bdc=100;// current gain Vcc=10 ;// supply voltage in volts Ic=10*10^-3;// collector current in amperes // Calculations Ve=0.1*Vcc;// emitter voltage in volts Ie=Ic;// collector current is equal to emitter current Re=Ve/Ie;// emitter resistance in ohms Rc=4*Re;// collector resistance in ohms R2max=0.01*Bdc*Re;// in ohms V2=Ve+0.7;// in volts V1=Vcc-V2;// in volts R1=(V1*R2max)/V2;// in ohms disp("Ohms",R1,"R1=") disp("Ohms",R2max,"R2=") disp("Ohms",Rc," Collector Resistance=") disp("Ohms",Re,"Emitter Resistance=") // Result // R1=488 ohms, R2=100 ohms, Rc=400 ohms, Re=100 ohms