| 摘要 |
PURPOSE:To prevent the production of switching distortion, by avoiding the switching of all the transistors regardless of the polarity of input signal and the greatness of load impedance and output voltage, through the provision of inversion amplifier. CONSTITUTION:In the SEPP power amplifying circuit consisting of transistors TR1, 2, 7, 8, the voltage dividing the emitter voltage of TR1, 7 into a half with the resistors 18, 19, is taken as the reference voltage, the voltage at the load terminal A is inverted and amplified 17 via the input resistor 14 (having feedback resistor 16) and the output voltage is fed to the emitter of TR1, 7 via the resistors 18, 19. According to the increase in the input signal of negative a half cycle, even if the potential at the point D is increased, the potential at the point C is changed to negative side with the presence of the amplifier 17, the potential of the emitter of TR1 is decreased to be kept at ON state. This is similar in case that input signal of positive half cycle is fed, resulting that TR1, 2, 7, 8 are always ON, avoiding the switching distortion. |
