Dynatron

The Dynatron is a special design of a historic electron tube having three electrodes which in their current-voltage characteristic has as a special area with a negative differential resistance. Thereby they can be used for generating electric oscillations in the context of an oscillator circuit. The Dynatron was developed in 1915 by Albert W. Hull.

Construction

The Dynatron consists of a centrally arranged inside the hot cathode which is surrounded on the outside by two anodes. The inner anode is interspersed with holes and is in operation at a higher electrical voltage than the outer second anode. The arrangement of the two anodes and the voltage distribution, it is, according to the secondary emission of electrons in a region of the characteristic at the desired negative differential resistance which is within the scope of oscillator circuits, the dynatron oscillator can be used for generating vibrations.

An extension is identified as " Pliodynatron " called electron tube dar. This is an additional fourth electrode, a control grid, placed between the hot cathode and the anode inner first. With this control grid, the frequency generated in the oscillator circuit can be influenced. The Pliodynatron is in principle and the structure is a tetrode, wherein conventional tetrodes with the desired dynatron secondary emission of electrons is undesirable at the anode.