When I hang it of the clock moves, moving itself from right on the left, and viceversa, it is used to say that "it oscillates", that is completes an oscillating movement, than hard until a force, that it can be mechanical, electrical worker or of other nature, it prevents it to stop themselves. Well, the electronics have taken control this verbo, making some use in many occasions. In particular, in order to interpret the behavior of the amplifier transistor which, if opportunely connected and fed, she can generate it marks them variable in the time, that is can "oscillate", without that to its base it comes supplied a precise message. And the total circuit, that it gives origin to such phenomenon, assumes the denomination of "oscillating circuit" or, more simply, "oscillator". But we return, for a moment, to the image of I hang it, in order to observe that its is not a continuous motion, but variable. Since the speed is maximum, when it assumes the vertical position, while it slows down, progressively, hand by hand that it catches up the extreme positions of right and left, on which, for a moment, firm. In short, if the mechanical phenomenon must be interpreted graphically, one notices to us that this is analogous to that one of the voltages and the currents sinusoidali electrical workers, therefore as indicated in the diagram of figure 1, on whose horizontal axis comes estimated the times, on the vertical one are conteggiate the speeds caught up from I hang it.

Fig. 1 - The oscillating movement of I hang it is interpreted, graphically, through one sinusoide; the same one that explains, analytically, the behavior of the alternated voltage.

Also in this case, the number of times, in which the sinusoide it is repeated in the time, takes the name of "frequency".
We move hour in the field of the oscillating transistor that, similarly to how much happens for hangs it, generates a variable voltage, of sinusoidale, interpretable shape with the diagram of figure 1, in which, this time, the vertical axis measure the voltages and not more the speeds, while the time and the frequency still are conteggiati on the horizontal axis. It exists, however, a great difference, between the range of values of frequency of the mechanical oscillations and those electrical workers, since before it is much limited, the second one, instead, can extend from less than an oscillation to the second, to several migliaia of million to the second. In this center, moreover, they will come it introduces and it analyzes to you the single oscillating circuits to you in a position to producing it marks them of vlf, it calls OSCILLATING BF. to you Because those to the 30 advanced frequency to KHz, they are calls OSCILLATING RF to you, that is, oscillating to radio frequency.