Classes of Diodes

We will put the different classes of diodes that are more common inside the electronic circuits that we could use.

- Union diodes.
- Diodes of top of contact.
- Diode issuers of light.
- Diode capacitivo (varicap).
- Diode Zener.
- Diode tunnel.
- Diode Gunn.

Union diodes: The union diodes are that we have come describing in this diodes section, that is to say, the one that consists of a crystal of germanium or of silicon, properly doped, and has a cylindrical form. There are diodes for low potency that are used very much like rectifiers of small devices. To this class of diode also he is met by the name of diodes of junction. It is very suitable to be learned of memory each of the electronic symbols of the diodes, it will facilitate the comprehension of the schemes to us, not only those of of electronic-roundtable.com, but also any scheme that they need to understand.

Diodes of top of contact: They possess a few properties similiares to the union diodes and the only difference is, in any case, the system of construction that has been applied. In the image there appears a scheme of one of these elements that consists of a contact top in the shape of wharf (1) that has connected with a type crystal P (2), which there is in turn in contact with a type crystal N (3). In the low part, a metallic base does of support and assures the rigidity of the set. Exactly just as it happens with the union diodes, the diode of top of contact behaves allowing to spend the current in only one felt.

Issuing light diodes: The issuing diodes also are known by the name of LED (initials of his English denomination Light Emitter Diode) that have the peculiarity of expressing light when they are crossed by the electric current. Since he wants that they obtain a quite living light and, also, with a minimal quantity of current (from the order to some tens milliamperes).
The issuing light diodes work for a complicated physical process in which they detach photons on having returned to his valency orbit. The removed luminous energy can be of green color if the element to been treated with gallium - phosphorus, or red if the been with gallium - arsenio. In fact the gallium is much known by the big applications variety that they to found in all order of electronic devices.

Diode capacitivo (varicap): This diode, also called diode of variable capacity, is, essentially, a diode semiconductor which principal characteristic is that of obtaining a capacity that depends on the inverse tension to him applied.
There are used especially in the circuits tuners of television and those of recipients of radio in FM.

Diode Zener: The diode Zener, also called regulatory tension diode, we it can define as an element silicon semiconductor that has the characteristic of a normal diode when it is employed at direct sense, that is to say, in step sense; but in inverse sense, and for an inverse current superior to a certain value, it presents a tension of constant value. This phenomenon of constant tension in the inverse sense turns to the Zener diodes in dipositivos exceptionally useful to obtain a relatively invisible tension to the changes of the tension of feeding, that is to say, like regulatory tension devices.

Diode Tunnel: This diode presents a curious quality that is revealed quickly on having observed his typical curve, which is seen in the graph. As for the current in blockade sense he behaves like a current diode, but in the step sense it offers a few variants as the tension that him surrenders. The intensity of the current grows with rapidity at first with very little tension value up to coming to the comb (C) where from, on having received major tension, a loss of intensity takes place up to D that rises again cuado exceeds all this area of the value of the tension.

Diode Gunn: This diode has characteristics very different from the previous ones, since it is not a rectifier. It is a question of a generator of microwave, formed by a semiconductor of two terminals that uses the called effect Gunn. When a continuous tension of 7 V is applied between plate and cathode, so that the plate is positive with regard to the cathode, the current that circulates along the diode is continuous but with a few superposed impulses of hyperfrequency that can be used to induce oscillations in a resounding cavity. In fact, the microwave emission takes place when the areas of high electrical field move from the plate to the cathode and from the cathode to the plate in the most rapid constant trip between both areas, what determines the frequency in the impulses.

He keeps on reading on diodes:

Typical of the Diodes.
Functions of the Diodes.
Codes of desidnación of Diodes Semiconductors.

To return to the principal Diodes page->