Search results
Results From The WOW.Com Content Network
The control grid is an electrode used in amplifying thermionic valves (vacuum tubes) such as the triode, tetrode and pentode, used to control the flow of electrons from the cathode to the anode (plate) electrode. The control grid usually consists of a cylindrical screen or helix of fine wire surrounding the cathode, and is surrounded in turn by ...
The mutual conductance tester tests the tube dynamically by applying bias and an AC voltage to the control grid, and measuring the current obtained on the plate, while maintaining the correct DC voltages on the plate and screen grid. This setup measures the transconductance of the tube, indicated in micromhos. [3]
The first grid, known as the control grid, (and sometimes other grids) transforms the diode into a voltage-controlled device: the voltage applied to the control grid affects the current between the cathode and the plate. When held negative with respect to the cathode, the control grid creates an electric field that repels electrons emitted by ...
The control grid of the variable-mu pentode is constructed so as to result in a given incremental change of control grid voltage having less effect on change of anode current as the control grid voltage increases negatively relative to the cathode. [7] The control grid often has the form of a helix of varying pitch. [8]
This additional control grid modulates the current that flows between cathode and anode. The relationship between current flow and plate and grid voltage is often represented as a series of "characteristic curves" on a diagram. Depending on the other components in the circuit this modulated current flow can be used to provide current or voltage ...
The control grid and cathode are operated as a diode while at the same time the control grid voltage exerts its usual influence on the electron stream from cathode to plate. In the circuit, a capacitor (the grid condenser) couples a radio frequency signal (the carrier) to the control grid of an electron tube. [16]
Plate detector circuit with cathode bias. Cathode bias RC time constant three times period of lowest carrier frequency. C L is typically around 250 pF.. In electronics, a plate detector (anode bend detector, grid bias detector) is a vacuum tube circuit in which an amplifying tube having a control grid is operated in a non-linear region of its grid voltage versus plate current transfer ...
Between the screen grid and the cathode is the control grid. The beam confining plates have been removed. The getter pan, getter pan supports and the upper mica disc have been removed. The elliptical helix of the screen grid surrounds the control grid. The screen grid support rods are on the left and right outside of the control grid support rods.