| 摘要 |
461,177. Valve amplifying circuits. RADIOAKT.-GES. D. S. LOEWE. May 7, 1935, No. 13407. Convention date, May 9, 1934. [Class 40 (v)] In a television amplifier the production of shadow effects in the received picture is avoided by arranging that the anode decoupling condensers receive voltages of opposed phase. As shown in Fig. 3, the amplifier 1 receiving the signal is coupled by a tap on its anode resistance 2 to the grid of a phaseopposed valve 1<1>. In this way the de-coupling condenser 5 receives impulses of opposite phase which neutralize each other and do not cause a cumulative shadow-producing charge on the condenser 5. Further push-pull stages may follow the stage 1, 1<1>, In Fig. 4 the same effect is produced, by connecting the condenser 5 for the first stage through a resistance 21 to a tapping on the anode resistance 21 of the second stage. Similar connections are provided between the second and third stages. A glow lamp 11 may be provided in place of the anode de-coupling condenser in the later stages, and this may be shunted by a byepass condenser for the higher frequencies. Glow lamps may also be substituted for the inter-valve coupling condensers 3. The Specification also states suitable limits for the time constants of the circuits comprising (a) the coupling condenser 3 and grid resistance 4, and (b) the anode feed resistance 6 and condenser 5. The anode resistance 21 may be divided into two sections and an inductance coil shunted by a damping-resistance interposed between them. The resistance 21 is then connected to a point on the earth side of the coil Fig. 7 (not shown). The Specification as open to inspection under Sect. 91 also refers to a multi-stage amplifier of the direct-coupled type with resistance-shunted condensers connected. between each anode and the following grid, and with glow lamps replacing the usual anode de-coupling condensers. This subject-matter does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specifications 325,833, 333,143, [both in Class 40 (v)], and 432,268. |
