| 摘要 |
PURPOSE:To achive a noncutoff type power amplifying circuit, by flowing a constant current to a resistor and producing a bias voltage of transistors (TR) at output stage with the voltage drop. CONSTITUTION:At no signal, constant current flows to resistors 43, 45 from a constant voltage source 31 and this voltage drop biases TRs 6, 7 and 8, 9. When a positive input signal is applied, the TRs turn on, and an output current flows to an output terminal 12 via a resistor 10. Since a voltage produced across the resistor 10 is given to resistors 39, 42, the current through the resistor 43 is reduced by the current flowing to the resistor 42 and a potential difference between connecting points P and Q is increased. Thus, the cutoff of the TRs 8, 9 is avoided. When a negative input signal is applied, the potential difference between the P and Q is extended to avoid the cutoff of the TRs 6 and 7. |
