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).
Use of non-inductive resistances in a starter's magnetic main switch circuit.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan3 | |
| Date | 12th January 1924 | |
| SECRETAL To F) E) from EFC. c. Rg.{Mr Rowledge} Da.{Bernard Day - Chassis Design} Wor.{Arthur Wormald - General Works Manager} c. EP.{G. Eric Platford - Chief Quality Engineer} CJ. BJ. BY.{R.W. Bailey - Chief Engineer} EFC2/T12.1.24. E.A.C. V4168B X.9650 - RE STARTER. Reference your R3/M1.1.24 and LeC.1802. In the text it is remarked that the magnetic main switch operating coil should have a non-inductive resistance in parallel with itself, and it suggests that one of about 20 ohms may be tried. On LeC.1802 no non-inductive resistance is shown across the magnetic main switch, but a non-inductive resistance is shown across the series combination of the actuator coil and series coil of the motor. Again, in the last par. of the text it is remarked "There is only the one non-inductive resistance mentioned that I can see any need or advantage to have". Are not both non-inductive resistances desirable ? Is not the more desirable one of the two the one that is shown on the drawing, because the contacts of the pull off switch, through which the actuator (teazer) current has to pass, have to carry a relatively large current, which current has to be broken at these contacts ? A further point is this - on the LeC. the magnetic main switch is shown with the lever connected to the live side of the battery, and the fixed contact in connection with the dead portion of the circuit (switch off). It is generally desirable to have the fixed contact connected to the live terminal of the battery and the moving lever Contd. | ||