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).
Magneto testing, detailing distributor condition and electrical test results.
| Identifier | WestWitteringFiles\F\February1921\ Scan80 | |
| Date | 3rd February 1921 | |
| Contd. -5- TAE.10 03-81-01 SHT 14.10 CT 001 ASSE .N .H EFC4/T3.2.21. edges of the contact points were blackened. The high tension ring and insulating cheeks were covered with light grey dust, but the track of the brush on the ring was clean. All the brass-work inside the distributor was covered with a green corrosion, particles of which were scattered over the base of the distributor. Beads of moisture had formed on the rotor and the interior of the distributor cover. All this would point to lack of the ventilation required by a jump spark distributor. It may be remembered that none of the Watfords would spark regularly on this test unless the gaps were reduced to 4 or 4.5 mm., the missed discharges going across the safety gaps. (8) & (9) These consist in taking the open circuit volt-speed and short circuit ampere-speed curves of the magneto primary, the results of these being exhibited on the accompanying photostat. (10) The short circuit test in which the magneto is run at 1500 R.P.M. for half a minute with timing lever central and secondary winding short circuited was O.K. on all three machines. (11) The open circuit test in which the machine was again run at 1500 R.P.M. for half a minute with the timing lever central, and with the high tension terminal not connected to anything, so that the secondary discharge takes place on the safety gap of the magneto, also went through successfully Contd. | ||