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).
Internal memorandum discussing experiments on a reduced side lamp illumination system for parking, detailing its impracticality.
| Identifier | ExFiles\Box 61a\2\ scan0240 | |
| Date | 8th March 1934 | |
| Sgt From Hs{Lord Ernest Hives - Chair}/Wst. c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Cx.{Major Len W. Cox - Advertising Manager} 26116 Hs{Lord Ernest Hives - Chair}/Wst.2/MA.8.3.34. REDUCED SIDE LAMP ILLUMINATION FOR PARKING. With further reference to your Sg.{Arthur F. Sidgreaves - MD}16/E.{Mr Elliott - Chief Engineer} 29.1.34., we have conducted experiments to investigate whether it is possible successfully to incorporate a parking resistance for the side lamps. We found however that putting a resistance in circuit which would reduce the current value to any appreciable amount also reduces the light to a practically negligible quantity. The minimum allowable brilliancy was obtained with a current flowing of .7 amperes which only means a saving of .3 amperes over the standard arrangement (assuming the use of recommended 4 watt lamp bulbs). We do not consider therefore that the small saving in current consumption is worth the extra complication involved in fitting the necessary 10 ohm resistance in the main circuit. We also note from P/LID.{A. J. Lidsey}1/HP.7.3.34., that the resistance proposal will also complicate the arrangement of the new proposed switchbox for our chassis. Another disadvantage we have discovered regarding this dimming proposal is that side and tail lamps vary in their rated current consumption, for instance it was found on test that the rated wattage of lamps varied about plus or minus 8 per cent. It could happen therefore when fitting replacement lamps with this resistance scheme, that if the lamps happened to be rated on the high side the illumination would be practically nil. Hs{Lord Ernest Hives - Chair}/Wst. | ||