Power dissipated across resistor R2 in milliwatts is given by: Power dissipated across resistor R1 in milliwatts is given by: Voltage across the collector and emitter of the transistor in volts is given by:Ĭurrent flowing through resistor R1 in milliamperes is given by:Ĭurrent flowing through resistor R2 in milliamperes is given by: Power consumed by the circuit in milliwatts is given by:Ĭollector voltage of the transistor in volts is given by: Therefore first base resistance in kilo-ohms is given by: Voltage across first base resistance R1 in volts is given by: In this case, the silicon transistor is considered. For the silicon transistor, Vbe = 0.7 volts. Where Vbe is the voltage across the base and emitter. The base voltage or voltage across R2 in volts is given by:
Therefore emitter current in milliamperes is given by:Įmitter resistance of the transistor in kilo-ohms is given by:Īpplying 10:1 rule of the firm voltage divider, second base resistance in kilo-ohms is given by: (It is normally represented by β or h-parameter hFE). 3: Screenshot of an example program output where Ic is the collector current and b is the current gain of the transistor. Therefore collector resistance in kilo-ohms is given by:īase current in milliamperes is given by: If voltage across the collector and emitter is Vce = 0.5Vcc, the remaining voltage of 0.4Vcc appears across the collector resistance. 2: Input parameters for the example entered by user Therefore emitter voltage in volts is given by: With no AC input signal, stable operating Q is maintained by using the one-tenth rule, which makes emitter voltage one-tenth of the supply voltage, Vcc. In order to bias the transistor properly with voltage-divider bias method, operating point Q should be at the centre of the DC load line (not shown here), where Vce= Vcc/2 and collector current Ic is as per the data sheet of the transistor. Coupling capacitors C1 and C2 are used to block the DC signal and pass the AC signal. Bypass capacitor Ce is used to bypass the AC audio-frequency signal towards the ground so that constant DC emitter voltage Ve is mainained to prevent negative feedback in the amplifier. Resistors R1, R2 and Re are used to provide proper voltages to base b, emitter e and collector c of T1, so that base-emitter junction is forward-biased and base-collector junction is reverse-biased.Ĭollector resistor Rc is used as the load that provides output voltage Vo. I1, I2, Ic and Ie, as shown in the figure, are DC currents. +Vcc is the supply voltage, Vi the input signal and Vo the output signal. 1: Circuit diagram of the single stage transistor amplifier The single stage transistor amplifier consists of a single npn transistor T1 (BC547), four resistors R1, R2, Rc and Re, two coupling capacitors C1 and C2, one bypass capacitor Ce connected across emitter resistor Re as shown in Fig.
0 kommentar(er)
