20W 40-500kHz PA 01

Other Circuits
20W power amplifier circuit shown in Figure 8-3. It consists of a pre-release level, and promote the level of three parts p power level in order to reduce the large phase shift
20W 40-500kHz PA 01 - schematic

in the feedback loop, and promotion of pre-release level are selected PNP silicon tube. Preamplifier stage constituted by a single-stage common-emitter VT1 amplifier, R6 introduction of a series of negative feedback, both to ensure the stability of the operating point level, but also increase the input impedance. So that when adjusting the gain, input impedance of the circuit can be kept stable e drive class 6 each tube emitter coupled directly by the local negative feedback VT2, VT3 composed by the amplifying circuit and R11, R13 composed of parallel voltage negative feedback to ensure constant p of the output signal level of the stage work and gain points by the transformer Tl is coupled to the power amplifier stage.

Leave Comment

characters left:

New Circuits