Power amplifier circuit, also known as back stage amplifier circuit, is a small voltage, current, amplifies the signal before, get enough power to drive the speakers work, it is divided into discrete components power amplifier circuit with integrated power amplifier. In order to protect speakers and amplifier circuits, added at the output of the power amplifier protection circuits.5Rdservice manual download site
Amplifier protection circuits in General with the boot delay protection, power off delay protection, over current protection, over voltage protection. Which boot delay protection is to prevent boot Shi work not stable produced of impact current on speaker and power zoom circuit of against; shut machine delay protection is to prevent shut machine work not stable produced of impact current on speaker and power zoom circuit of against; had pressure and had flow protection circuit of role is Dang amplifier appeared midpoint offset and big of static current Shi automatically disconnect following electrical to protection speaker and power zoom circuit.5Rdservice manual download site
5Rdservice manual download site
5Rdservice manual download site
Because of all this part of the circuit in the amplifier are basically the same, circuit AV130 as an example, specific signal flow diagram as shown in the figure, circuits at various levels are as follows:5Rdservice manual download site
5Rdservice manual download site
1. mute: mute when in need, the input signal was bypassed, so no sound output.5Rdservice manual download site
5Rdservice manual download site
2. Exchange of negative feedback: its parameters determine voltage amplification of the entire amplifier circuits, but also has a stable operating point.5Rdservice manual download site
5Rdservice manual download site
3. differential amplifier stage: it is the first level of the signal input amplifier using differential amplifier, aims to reduce the drift.5Rdservice manual download site
5Rdservice manual download site
4. mirror a constant current source: to provide differential circuit of emitter current.5Rdservice manual download site
5Rdservice manual download site
5. voltage amplification: carry out appropriate voltage amplification of the signal.5Rdservice manual download site
5Rdservice manual download site
6. "temperature WD" compensation: for output to provide an appropriate static operating points, taking up the "temperature of WD" form of compensation.

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