The Triode as a High-Frequency Generator

Author: E.E. Kimberly

A circuit such as shown in Fig. 27-26 may be used to provide variable-frequency a-c voltages for such purposes as radio transmission and operation of stroboscopic lamps. In Fig. 27-26 the triode acts as an amplifier of any slight signal applied to it. The amplified signal passes through the coil R which, if properly related inductively to L, will induce an additional emf in L; and this will add to the original signal. This action is called regeneration. The parallel circuit LC will then oscillate at its own natural frequency (resonance), and an a-c output voltage will appear at the transformer terminals. The frequency of the output voltage may be controlled by the adjustment of L or C or both. The output energy is derived from the battery B.

Fig. 27-26. The Triode as an A-C Generator