Grid control
Under grid control refers to the possibility of the current flow in a tube , by a control electrode , which as a control grid to influence is referred to. In the case of vacuum tubes, this allows the current in the anode circuit to be continuously influenced; in the case of gas discharge tubes such as mercury vapor rectifiers , only switching on the anode current (ignition) is possible. To interrupt the anode current, it is necessary to apply a counter voltage or a zero crossing in the current flow.
The analog option exists for semiconductor components, but the control electrodes are usually not referred to as grids here. Here, transistors correspond to electron tubes and thyristors to thyratrons .