# 2N2222A Voltage Divider from Lab (Excel)

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```					                Part 1a             Class-A Amplifier: DC Bias
Calculate the DC bias values for the circuit below.

Design Spec
VCC                                        10         Volt
Vi (peak)                                  10         Volt
VO (RMS - Measured)                       2.804       Volt
R1                                        1000        Ω
R2                                         180        Ω
RE                                         20         Ω
RC                                         120        Ω
VBE                                        0.7        Volt
VB = R2 * VCC / R1 + R2                   1.525       Volt
VE = VB - VBE                              0.83       Volt
IC ≈ IE = VE / RE                        0.04127      Amp
VRC = IC * RC                              4.95       Volt
VC = VO = VCC - VRC                       5.047       Volt

Part 1b
Construct, measure and calculate IE based on measured values.
VB-meas                                   1.491       Volt
VE-meas                                   0.752       Volt
VC-meas                                   5.515       Volt
IB (meas)                               0.00022623    Amp
IC ≈ IE = VE / RE                        0.03760      Amp
Part 2a

Calculate power and efficency values.
β = IC / IB                           166.203
Pi (dc) = VCC * IDC                     0.413      Watt
VO = VC-calculated                      5.047      Volt
PO (AC) = (Vpeak2 / 2) * RC             0.033      Watt
%η = 100 * (PO (AC) /Pi (DC))           7.938      %

Part 2b

Using the oscilloscope adjust the input signal to obtain
an undistorted output signal, measure and record.
Vi-rms (meas)                          7.069        Volt
VC = VO-rms (meas)                      2.753      Volt
Part 2c
Using the measured values calculate the power and efficency
Pi (DC) = VCC * IDC                   0.413     Watt
2
PO (AC) = Vc-rms / RC                 0.063     Watt
%η = 100 * (PO (AC) /Pi (DC))        15.303     %

Compare the measured values of power and efficency obtained in Parts 2b and 2c.
Both have very low efficency ratings

Part 2d
Reduce the input signal to 1/2 of part 2b
Measure and record
Vi-rms (meas)                           3.5     Volt
VC = VO-rms (meas)                     0.72     Volt
Part 2e
Calculate input power and efficency values of the 1/2 input signal.
Design Spec
VCC                                       10       Volt
Vi (peak)                                 5        Volt
VC = VO (RMS - Measured)                 1.439     Volt
R1                                       1000      Ω
R2                                       180       Ω
RE                                        20       Ω
RC                                       120       Ω
VBE                                       0.7      Volt
VB = R2 * VCC / R1 + R2                  1.525     Volt
VE = VB - VBE                            0.83      Volt
IC ≈ IE = VE / RE                       0.04127    Amp
VRC = IC * RC                            4.95      Volt
VC = VO = VCC - VRC                      5.047     Volt

Part 2f
Using the measured values calculate the power and efficency
Pi (DC) = VCC * IDC                   0.413     Watt
PO (AC) = Vc-rms2 / RC                   0.017     Watt
%η = 100 * (PO (AC) /Pi (DC))            4.181     %
Part 3a
Calculate the pwr ratings for a class-B amplifier

Design Spec
VCC                                              10        Volt
Vi (peak)                                         -        Volt
VC = VL = VO (peak)                               1        Volt
R1                                              1000       Ω
R2                                              1000       Ω
RE                                                -        Ω
RC                                                -        Ω
RL                                               10        Ω
VBE                                              0.7       Volt
IL = VO/RL                                       0.1       Amp
IDC = 2/π * IL-peak                             0.064      Amp
Pi-(dc) = VCC * IDC                             0.637      Watt
2
PO-(ac) =   VL-peak    / 2*RL                   0.050      Watt
%η = (PO-(ac) / Pi-(dc)) * 100                7.85398163   %
Part 3b           VO = 1 volt
Using the measured values calculate the power and efficency
Vi-rms (meas)                         0.919     Volt
VC = VO-rms (meas)                   0.676      Volt
VC = VO-peak                           1        Volt
IL = VO/RL                            0.1       Amp
IDC = 2/π * IL-peak                  0.064      Amp
Pi (DC) = VCC * IDC                  0.637      Watt
2
PO (AC) =    Vc-rms    / RL          0.046      Watt
%η = 100 * (PO (AC) /Pi (DC))        7.178      %

Part 3c           VO = 2 volt
Using the measured values calculate the power and efficency
Vi-rms (meas)                         3.96      Volt
VC = VO-rms (meas)                   1.234      Volt
VC = VO-peak                           2        Volt
IDC (meas)                           0.045      Amp
Pi (DC) = VCC * IDC                  0.453      Watt
PO (AC) =    Vc-rms2   / RL          0.152      Watt
%η = 100 * (PO (AC) /Pi (DC))       33.615      %
Design Spec multisim
VCC                                 10       Volt
Vi (peak)                           10       Volt
VO (RMS - Measured)                2.804     Volt
R1                                 1000      Ω
R2                                  180      Ω
RE                                  20       Ω
RC                                  120      Ω
VBE                                 0.7      Volt
VB = R2 * VCC / R1 + R2            1.491     Volt
VE = VB - VBE                      0.752     Volt
IC ≈ IE = VE / RE                 0.03738    Amp
VRC = IC * RC                      4.485     Volt
VC = VO = VCC - VRC                5.515     Volt

VB-meas                            1.491     Volt
VE-meas                            0.752     Volt
VC-meas                            5.515     Volt
IB (meas)                       0.00022623   Amp
IC ≈ IE = VE / RE                 0.03760    Amp
IC                                 0.03738 Amp
IB                              0.00022623 Amp
β = IC / IB                     165.207974
Pi (dc) = VCC * IDC               0.374      Watt
VO = VC-calculated                5.515      Volt
PO (AC) = (Vpeak2 / 2) * RC       0.033      Watt
%η = 100 * (PO (AC) /Pi (DC))     8.765      %
es of power and efficency obtained in Parts 2b and 2c.

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 views: 61 posted: 12/10/2011 language: pages: 9