| 摘要 |
PURPOSE:To simplify a circuit and to reduce a cost as an electric power amplifier, by using both a capacitor for automatic release in a safety operation area protecting circuit, and a capacitor for removing an electric power supply ripple. CONSTITUTION:Both output transistors (TR) Q19, Q21 are cascaded and the B- class push-pull operation is executed. On the base of a TR Q23, a constant- current TR Q9 for supplying a bias current is provided. A capacitor C101 for removing an electric power supply ripple component of a bias current circuit is connected to the connecting point of resistances R9, R10 through the 8-th terminal. Accordingly, in case when the TR Q19 has been deviated from the prescribbed operation area, the TR Q19 is cut off forcibly by the bias controlling circuit, and the operation of the TR Q19 is released by a time constant which has utilized the capacitor C101. |
