Question

SOLVE PROBLEM #2

A class B complementary symmetry amplifier using ONE power supply is shown. Let Vcc = 12 V, R1 = R3 = 1 k22, R2 = 1702, Rs = 100 N, and Ru = 8 12. Transistors Qi and Q2 are matched with B = 100. Vcc ic R1 AC Load Line R C1 Vcc HE 21 ZRU DC Load Line C2 Vin R2 HE le2 Vo не } 22 C Voc R3 2 a) b) Determine the PLoad(max) and Psupply. Determine the max efficiency. Problem #2 Repeat Problem # One using TWO power supplies. Let Vcc = = 12 V.

Answer 1

PROBLEM #2 SOLUTION

Consider the diagra below with two V_CC = ± 12 V

Vec R1 R C: C R2 W Vo R w C R3 C-Voc

To achieve maximum power operation the output voltage must be

  

Part a)

Here the maximum input (supply) power is given by,

2V сс maximum, P (de) = 2(12) TX8 = 11.46 W ARL

maximum output (load) power is given by,

$maximum,\: P_o(ac)= \frac{V_{cc}^2}{ 2R_L}= \frac{12^2}{2 \times 8}= 9\: W$

Part b)

]At maximum input and output power points, maximum efficiency is achieved

$\because\: \: \: \: \: \: \: \%\eta =\frac{P_o}{P_i} \times 100 \: \%= \frac{9}{11.46} \times 100$

$= 78.539 \approx 78.54 \%$

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NB: For reference use Electronic Devices and Circuit Theory by Robert L Boylestad and Louis Nashelsky