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).
Problem of side lamp bulbs burning out due to dynamo overcharging and comparing charging systems.
| Identifier | ExFiles\Box 163\6\ img166 | |
| Date | 8th June 1932 | |
| X6016 To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Hy.{Tom Haldenby - Plant Engineer} Cx.{Major Len W. Cox - Advertising Manager} c. to PN.{Mr Northey} Wor.{Arthur Wormald - General Works Manager} c. to SS.{S. Smith} Hs{Lord Ernest Hives - Chair}/Wst.4/KT. 8.6.32. BURNING OF SIDE LAMP BULBS. We must bear in mind that any attempt to increase the dynamo charge on the 2 O/25 such as fitting the 40/50 dynamo will still further aggravate the side lamp question. We have already had complaints of side lamps burning out and we know that the voltage can rise to as high as 16.0 with only the side and tail lamp load on the battery. The repeated failure of tail lamps would prove very annoying to customers. We have taken up with the lamp bulb makers the question of supplying 16 volt side and tail lamps but they state that they cannot do this without a lot of expense and in any case it would be extremely difficult for customers to buy spares of such a special bulb. We consider, therefore, that an urgent decision should be made with regard to whether we shall continue as at present to have full dynamo charge in the side and tail position as well as the head, side and tail position. The argument for putting the full charge on the S & T position was that with the half charge resistance inserted the cutting in point was so late as to prevent the battery keeping up during town running at night. The Lucas people got over this difficulty with their three charge system which does not permit full charge in the S & T position. We would point out, however, that our 40/50 dynamo with our half charge resistance inserted gives about the same cutting in speed as the Lucas dynamo with its S & T resistance inserted (Known as the winter charge position). The advantages of the Lucas system over our own therefore are :- (a) The battery is prevented from overcharge in the summer time by the use of the extra resistance inserted when the charging switch is in the "Summer charge" position. | ||