标题: 458. This varying direct current [打印本页] 作者: smshih223 时间: 2011-5-12 18:46:45 标题: 458. This varying direct current
458. This varying direct current
When the waves set up oscillations in the primary of the tuning coil the energy of them produces like oscillations in the closed circuit which includes the seeondary coil and the condenser; the alternating positive and negative voltages of these are impressed on the grid and these, as we have seen before, cause similar variations of the direct current from the B battery which acts on the plate and which flows between the latter and the filament.This varying direct current, however, is made to flow back through the third, or tickler coil of the tuning coil and sets up in the seeondary coil and circuits other and larger oscillating currents and these augment the action of the oscillations produced by the incoming waves. These extra and larger currents which are the result of the feedback then act on the grid and cause still larger variations of the current in the plate voltage and hence of the Juicy Couture Bags current of the B battery that flows through Juicy Couture Handbags the detector and the headphones. At the same time the tube keeps on responding to the feeble electric oscillations set up in the circuits by the incoming waves. This regenerative action of the battery current augments the original oscilla¬tions many times and hence produce sounds in the headphones that are many times greater than where the vacuum tube detector alone is used.Operation of Autodyne and Heterodyne Juicy Couture Sale Receiving Sets.-On page 109 [Chapter VII] we discussed and at A in Fig. 36 is shown a picture of two tuning forks mounted on sounding boxes to illustrate the principle of electrical Juicy Couture Outlet tuning. When a pair of these forks are made to vibrate exactly the same number of times per seeond there will be a condensation of the air between them and the sound waves that are sent out will be augmented. But if you adjust one of the forks so that it will vibrate 256 times a seeond and the other fork so that it will vibrate 260 times a seeond then there will be a phase difference between the two sets of waves and the latter will augment each other 4 times every seeond and you will hear these rising and falling sounds as beats.