Amplifiers with floating power supply

. In the figure, VTi, VTz and R4~ island together form a power supply bias circuit. The power supply voltage
is ±35V. After being reduced by the 500C1 resistor, the voltage at point A is 30VoR, and R is the bias resistor r of VTi. In the static state
, Vc=[R4"R4+Rs)]. VA=15Vo. If the transistor is ignored voltage drop, then the emitter voltage
Vel of VTi = 15V, which is the static operating voltage of Jcl.
    When the circuit is working, the output terminal of the island l will have an audio signal voltage output. At this time, the code = Qiao + etc., V = one Qiao ten Dan
    2 0
This means that when there is a signal output, the power supply voltage of Icl will dynamically change with the size of the output signal voltage, which
increases the output voltage by a value in the same direction, thus increasing the amplitude of the output voltage. It is estimated that the maximum range can
reach ±24Vo
    Rio～R13. VDi, Ⅵ呸, and Vr7, Ⅵton, ‰, R21 and RP form the bias circuit of the output stage, which is
the same as the general bias circuit. VT3~VT6 form a composite complementary Push-pull output stage. The circuit output power can be up to 100%.
    Circuit component selection: VTi uses 2N5551, VT2 uses 2N5401, VT3 uses 2SC2275A, VT4 uses
2SA1985A, VTs uses 2SC3280, VT6 uses 2SA1301, VT7 uses 2SC2073, VDi and VDb
use 1N41480
    Although this floating power supply method can increase the output voltage and increase the output power, its drawback is that it
will cause asymmetry in the power supply voltage and imbalance in the operating point of the op amp at the maximum output. Therefore, it can only be used when the output power is small. It has good
working characteristics, but cannot display the high indicators of high-performance operational amplifier when the output power is large.