Transistor amplifies the sound signal
The base of the triode is connected to two resistors respectively. One resistor is connected to the power supply, and the other is connected to the ground. Change the resistance from the base to the power supply to select a suitable operating point. Connect an input coupling capacitor to the connection node of the two resistors and the base of the triode to access the input signal. The collector is connected to the power supply through a load resistor, and an output coupling capacitor is connected to the junction of the load resistor and the collector of the triode. The emitter of the transistor is connected to the ground with a small resistance to generate DC negative feedback and stabilize the operating point of the transistor. Connect a large-capacity capacitor to the resistor from the emitter of the transistor to the ground to ensure that the AC potential of the emitter of the transistor is zero to prevent AC negative feedback and increase the amplification. Pay attention to the polarity of the input and output coupling capacitors.
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