. The Bell System technical journal . Fig. 3—Circuit of experimental bridge oscil tor. coated major faces between small metal electrodes ground to fit, and byevacuating the container. Some of the circuit parameters are listed below: Ri = Tungsten-filament lamp, Ri = 100 ohms, Rs = 150 ohms, Zi = 100 kc. crystal. Characteristics at resonance:i?4 = 114 ohms,Xl = Xc= 11,900,000 ohms,Q = 104,000,i?5 = i?6 = 150 ohms (approx.),i?7 = 500 ohms,R% = 200 ohms,ImI = 422 ( dh voltage gain from e to E). 584 BELL SYSTEM TECHNICAL JOURNAL. Fig. 4—Experimental bridge stabilized oscillator without provisi
. The Bell System technical journal . Fig. 3—Circuit of experimental bridge oscil tor. coated major faces between small metal electrodes ground to fit, and byevacuating the container. Some of the circuit parameters are listed below: Ri = Tungsten-filament lamp, Ri = 100 ohms, Rs = 150 ohms, Zi = 100 kc. crystal. Characteristics at resonance:i?4 = 114 ohms,Xl = Xc= 11,900,000 ohms,Q = 104,000,i?5 = i?6 = 150 ohms (approx.),i?7 = 500 ohms,R% = 200 ohms,ImI = 422 ( dh voltage gain from e to E). 584 BELL SYSTEM TECHNICAL JOURNAL. Fig. 4—Experimental bridge stabilized oscillator without provisionfor temperature control. Figure 5 shows the resistance of the lamp Ri plotted against thepower dissipated in its filament. The large rise in resistance for smallamounts of power is due to the effective thermal insulation providedby the vacuum surrounding the filament and to low heat loss by radia-tion. The lamp operates at temperatures below its glow point, assur-ing an extremely long life for the filament. 180 160 (/) 140 5 I O Z 120 Ui O Z 100 < \- </) 12 eoa. Q. i 60 4020 _^^ ^ ^ ^ -■ y y^ / / / 1 23 4-56 789 POWER INTO LAMP IN MILLIWATTS Fig. 5—Characteristic of lamp used for R\. THE BRIDGE STABILIZED OSCILLATOR 585 The particular value assumed by i?i in the circuit of Fig. 3 is ap-proximately (R2R3)/Ri = [(100)(150)]/114 = ohms, and hencefrom Fig. 5 it follows that the power supplied to the lamp is about The voltage across the lamp is computed to volt, and across the e
Size: 2631px × 950px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
