On the Calculation of Self Inductance of Coils wound on Square Forms

抄録

1. In the former paper (This Journal p. 535 1919; Researches of Electrotechnical Lab., No. 73, 1918.) the writer treated on the solenoid with rectangular section and derived a formula for the calculation of the self inductance of such solenoid. In the present paper the writer discusses the range of application in which the formula can be used with fair accuracy.
2. Dr. Esau's criterion on the applicability of the writer's formula (Jahrb. f. drahtl. Telegraphie, Dec. 1921) is reviewed and it is shown that Esau's conclusion must be modified owing to his erroneous calculation of the correction factor.
3. From experiments as well as calculation, it is shown that the writer's formula may be applied with accuracy for all the coils however flat may be with the ratio of pitch to the diameter of the wire g/2ρ less than 6 or 7 and even for coil with this ratio so far 20 or 30 the formula may be applied with several percents of error for moderate values of the ratio of the side of section to the length of coil (δ) such as 40 or 50. It is also shown that the range of δ applicable with certain percentages of error, becomes limited as the ratio of g/2ρ increases.
4. Formula for the self inductance of solenoid with similar concentrated windings at equal intervals is given.