Power Supplies, Power Conservation, and Efficiency - Mô hình bộ khuếch đại điện áp của chúng tôi cho thấy nguồn cung cấp năng lượng và các kết nối mặt đất. Công suất tín hiệu chuyển tải được chuyển đổi từ sức mạnh dc cung cấp bởi các nguồn cung cấp năng lượng. | Power Supplies Power Conservation and Efficiency Introduction to Electronics 11 Power Supplies Power Conservation and Efficiency Fig. 23. Our voltage amplifier model showing power supply and ground connections. Vaa The signal power delivered to the load is converted from the dc power provided by the power supplies. DC Input Power PS VAAIA VBBIB 13 This is sometimes noted as PIN. Use care not to confuse this with the signal input power Pị . Conservation of Power Signal power is delivered to the load Po Power is dissipated within the amplifier as heat PD The total input power must equal the total output power Ps Pi Po Pd 14 Virtually always Pi PS and is neglected. Power Supplies Power Conservation and Efficiency Introduction to Electronics 12 Fig. 24. Our voltage amplifier model showing power supply and ground connections Fig. 23 repeated . V A Efficiency Efficiency is a figure of merit describing amplifier performance P n - X100 15 Ps Amplifier Cascades Introduction to Electronics 13 Amplifier Cascades Amplifier stages may be connected together cascaded Notice that stage 1 is loaded by the input resistance of stage 2. Gain of stage 1 A Vo1 v 1 v1 16 Gain of stage 2 A -Vol- vo 2 Av 2 v 2 vo1 17 Gain of cascade A Ko1 Ko2 A A voc v v v 1 v 2 18 We can replace the two models by a single model remember the model is just a visualization of what might be inside ii o - n vi1 ỈRÍ1 Ro2 ĨỌ2 I---Wv 0 vo2 ÝAvoM I--------o Fig. 26. Model of .
