| 摘要 |
<p>452,927. Valve circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London.-(Assignees of Koch, W. R. ; 220, Cooper Street, Camden, New Jersey, U.S.A.) March 1, 1935, No. 6560. Convention date, March 1, 1934. [Class 40 (v)] A thermionic relay or oscillator system comprising a pair of pentodes, the anode of each being directly connected to the screen grid of the other, is characterized by a linkage time-delay network associated with the control grid of one of the valves. In Fig. 1, input or control potentials are applied to terminals 56, the control grid 40 of valve 30 being connected over condenser 53 to the screen grid 39 of the same valve. Condenser 53 and resistance 42 constitute the timedelay network. The control grids are differently biassed, source 55 providing higher negative bias than source 54. The output may be applied to a relay 46 as shown. Impulses applied to input 56 cause the relay to pass through a complete cycle, the period of which is dependent on the network 42, 53 ; a negative impulse causes the plate current of valve 31 to decrease to zero, the current of valve 30 increasing to a maximum ; the conditions revert to normal after the time-delay. If the delay network is connected to the control grid with the smaller negative bias, the arrangement constitutes a multivibrator (as shown in Fig. 2). The delay network may be connected in the lead joining the anode of the highly biassed valve and the screen-grid of the other, Fig. 3 (not shown.) ; or separate time-delay networks may be provided between the control grid of each valve and the cathode of the partner valve, the anodes and screen grids being crossconnected as in Fig. 2, (Fig. 4 not shown). The oscillator output may be taken from any of the terminal pairs 58, 59, 60, 61, Fig. 2. With this type of oscillator, the oscillations in the low-bias valve have a rectangular wave-form while those in the partner valve are substantially saw-toothed. The Specification as open to inspection under Sect. 91 describes a D.C. amplifier arrangement comprising two screen grid pentodes, the anode of the first valve being directly connected to the screen grid of the second. This subjectmatter does not appear in the Specification as accepted.</p> |
