Clipping

Author: N.H. Crowhurst

Grid clipping results when the grid voltage passes the zero point and current begins to flow in the grid circuit.

Another kind of distortion occurs because the input fluctuations abruptly cease to produce a corresponding output fluctuation. The most common cause of this is known as grid clipping. Normal amplification takes advantage of the fact that, when the grid has a negative voltage, no grid current flows. When the grid passes the zero point between negative and positive, however, grid current will start to flow. Thus, when the grid is negative, no current flows in the grid circuit, and the applied signal is undistorted. When the grid reaches the zero point, however, it starts to draw current, and "short-circuits" positive-going voltage beyond that point.