| 摘要 |
PURPOSE:To prevent pop tone, by providing the stable circuit triggered with the voltage greater than that caused by the steadystate operation of the input and output circuits. CONSTITUTION:The voltage of the feedback capacitor C101 mounted externally is zero with discharge prior to the power supply switch application. When the power supply switch SW is applied, the regulating power supply circuit 6 is immediately operated and the emitter voltage of transistor Q27 is caused. The potential Vq of the neutral point Q of the output circuit 4 is remained zero with the operation of the driver circuit 3. In the transient state of the power application, the neutral point potential Vq is set to ground potential first, and since the base potential difference between the input circuit transistors Q1 and Q2 is risen up to 1/2 Vcc with the state decreased to a given level, the pop tone can be avoided. |
