| 摘要 |
PURPOSE:To suppress the higher harmonic component which is caused during the clipping and to prevent the occurrence of the unpleasant noise, by detecting the signal level at a prescribed circuit contact set at a stage before an output amplifying element and then limiting the output current when the signal level exceeds the prescribed value. CONSTITUTION:The level of an output Va of a voltage amplifying stage 1 is detected by a level detecting circuit 4 before an electric power amplifying stage 2 has a clipping operation. When the level of the output Va exceeds the prescribed value, a detecting output corresponding to the relevant level is produced. A current limiting circuit 5 is actuated in response to the detecting signal, and the current flowing to an output element is suppressed in accordance with the prescribed level. Thus if there is no circuit 5, an output power element of the output stage 2 is saturated when the input signal level increases to exceeds a certain value. Then the feedback voltage is also saturated and does not increase any more. Therefore an extremely large amount of effective input is applied to a voltage amplifying stage 1 to produce an evil effect to an amplifier. This evil effect, however, can be eliminated by the circuit 5. |
