From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Calculations and test results for setting angles on an intermediate output S.S. dynamo.
| Identifier | ExFiles\Box 60\1\ Scan117 | |
| Date | 1st August 1929 | |
| X6004. X.8665. INTERMEDIATE OUTPUT S.S. DYNAMO. N angle determined by F.J.A. geometrically from winding diagram = 55.5° B angle required by C.A.P. tentatively for this machine = 9° Therefore M angle given to D.O. for armature = 46.5° Shop check of M angle gave = 45.25° on No.1 armature and 45.25° on No.2 " Running check of B angle gave 10.25° This gives an N angle of 55.5° thus agreeing with N angle determined geometrically. B.P.D. Commutator end plate slotted by C.A.P. to provide trial B angles of 6°, 10°, 14°, 18°, 22° Resulting maximum amperes and corresponding C angles came out as respectively 16.3, 16.5, 16.2, 16.2, 15.5 124.5°, 125°, 127.5°, 133°, 137.5° The relative shapes, maxima, etc. of the five respective ampere curves, general commutation and noisiness, were considered, and a further comparison of two Bangle cases viz. 15° and 18° was decided upon. This comparison was to be made not only on the "maximum permissible" output now to be known as the "higher output" but also on suitably reduced output to be known as the "lower output". Angles ultimately arrived at B = 16° C = 131° and 136° for higher and lower outputs. | ||