Abstract

Synopsis

Direct capacity, direct admittance and direct impedance are defined as the branch constants of the particular direct network which is equivalent to any given electrical system. Typical methods of measuring these direct constants are described with especial reference to direct admittance; the substitution alternating current bridge method, due to Colpitts, is the preferred method, and for this suitable variable capacities and conductances are described, and shielding is recommended. Proposed methods are also described involving the introduction of electron tubes into the measuring set, which will reduce the measurement to a single setting or deflection. This gives an alternating current method which is comparable with Maxwell’s single null-setting cyclical charge and discharge method. Special attention is drawn to Maxwell’s remarkable method which is entirely ignored by at least most of the modern textbooks and handbooks.

© 1922 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |

  1. Proofs of the mathematical results included in the present paper will be supplied in an appendix which will be added to the reprint of the paper which is to appear in an early number of the “Bell System Technical Journal.”
  2. Electricity and Magnetism, v. 1, p. 350, (ed. 1892).
  3. Ibid., p. 110.
  4. The Shielded Balance, El. W.,  43, 1904, (647–649).

1904 (1)

The Shielded Balance, El. W.,  43, 1904, (647–649).

El. W. (1)

The Shielded Balance, El. W.,  43, 1904, (647–649).

Other (3)

Proofs of the mathematical results included in the present paper will be supplied in an appendix which will be added to the reprint of the paper which is to appear in an early number of the “Bell System Technical Journal.”

Electricity and Magnetism, v. 1, p. 350, (ed. 1892).

Ibid., p. 110.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (9)

Fig. 1
Fig. 1

Equivalent direct capacities. G4 = C14+C24+C34 = grounded capacity of branch-point 4

Fig. 2
Fig. 2

Colpitts substitution bridge method for direct capacity

Fig. 3
Fig. 3

Potentiometer method for direct capacity

Fig. 4
Fig. 4

Null-impedance bridge method for direct capacity

Fig. 5
Fig. 5

Maxwell discharge method for direct capacity

Fig. 6
Fig. 6

Bridge for determining hypothetical capacity between two terminals with other terminals balanced and ignored

Fig. 7
Fig. 7

Double bridge for direct capacity

Fig. 8
Fig. 8

Ammeter circuit for determining direct capacity

Fig. 9
Fig. 9

Variable direct conductance and capacity standard for direct admittance bridge

Equations (6)

Equations on this page are rendered with MathJax. Learn more.

C 12 = C - C ,
C 13 - C 14 = C + C - 2 C °
C 12 = R R C G 1 = S - R R C
C b = 2 ( C - C o ) G 2 - G 1 = 2 ( C - C o )
C 12 = 1 2 ( G 1 + G 2 - G 12 ) = 1 2 C
C 12 = I 2 π f E