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).
Responding to a query on a Bentley III, detailing an investigation into voltage control issues and outlining electrical load data.
| Identifier | ExFiles\Box 168a\3\ img087 | |
| Date | 29th October 1938 | |
| To. Rm.{William Robotham - Chief Engineer} Dynamo 6142 CHILDS CHATEAUROUX. L/.29.10.38. 8.B.V.- BENTLEY III. Thank you for your memo Rm{William Robotham - Chief Engineer}/RC.{R. Childs}24/JH.26.10.38. We have traced the apparent irregularity of the voltage control to a sticking ammeter needle which did not fall back to normal charging rate after tooting the horns. There was also intermittent contact on the ignition warning lamp which further misled us. Here are the answers to your questions which appear to indicate that there is nothing the matter with the voltage control unit. 1) Average number of hours (per 24 hours) run in. a) Daylight......... 11.1/2 hours. b) Darkness........ 7. hours. 2) Total load and units composing same, during. a) Daylight. Ignition & Petrol Pumps. 0.5 amps. Heater (6 hours)..... 2.0 amps Screen wipers (1-2 hrs). 1.5 amps Radio (4-5 hrs)...... 4.0 amps ------------------ 8.0 amps b) Darkness. Lamps.............. 12.0 amps. All above........... 8.0 amps ------------------ 20.0 amps. 3) Usual charging rate. a) Daylight....... 6 - 10 amps b) Darkness....... 0 - 1 amps 4) With 18-19 amps load charging current does not exceed 1-2 amps. 5) With ignition and petrol pumps only charging, current does rise to and remain steady at a maximum with no further rise with increase of speed. ------------ Rm{William Robotham - Chief Engineer}/LMW. J.Waller | ||