12W Amplifier Circuit Using 741 Op Amp Circuit Diagram
A 12 watt audio amplifier operating on a dual symmetrical supply of ± 12 volts. The 741 provides the required gain while the speaker drive is provided by the complementary Darlingtons T1, T2 and T3, T4.The input signals for the darlingtons are derived from the supply current of the 741. Since R6 is connected to the ground, the positive or negative signal currents also pass through R4 or R5. The voltage drop across these resistors serves as the input signal to the transistor pairs. An overall dc negative feedback from the common collector junction of T2 and T4 stabilises the dc conditions of the circuit and keeps the junction point at zero volts. Hence, no coupling capacitor is required for the speaker. 12W Amplifier Circuit Using 741 Op Amp Circuit Diagram PARTS LIST R1 10KΩ R2 4.7KΩ R3 270KΩ R4 1KΩ R5 1KΩ R6 47Ω 1W C1 50 Pf C2 0.01 µF T1 BC178 T2 2N6107 T3 AC108 T4 2N5294 IC LM741 LS1 50W 4Ω