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).
Summary of details of operating voltages for temperature-compensated auto and green lamp switches.
| Identifier | ExFiles\Box 60\3\ Scan099 | |
| Date | 28th December 1928 | |
| X4040 28.12.28. SUMMARY OF DETAILS OF OPERATING VOLTAGES OF TEMPERATURE COMPENSATED AUTO AND GREEN LAMP SWITCHES. X4008 AUTO SWITCH B. 8-EX. This instrument, tested on the road on X8-EX, on 13.7.28, was found to operate at 15.0 volts and reclose at 13.0 volts. The temperature compensation was found to be good. The resistance wire is Eureka. GREEN LAMP SWITCH G.{Mr Griffiths - Chief Accountant / Mr Gnapp} (12EX) This was adjusted on the bench to close at 16.8 volts after being heated up on 16.8 volts. It was then found to open at 9.0 volts and to close in the cold condition at 16.3 volts. A road test on 12-EX for consistency of operation was performed (see report AD.10.13728.). It was found in these circumstances to close at 16.2 or sometimes at 16.0 volts on a bad road. These figures it will be noted are lower than the bench setting. Latterly it was removed from 12-EX and again bench tested, when the closing point was found to be 16.6 volts warm, and the general condition good. GREEN LAMP SWITCH H.{Arthur M. Hanbury - Head Complaints} (9G3) This instrument was, as in the case of G, set to close at 16.8 volts after being heated up to 16.8 volts. In the warm condition its opening point was found to be 9.7 volts. In the cold condition its closing point was found to be 16.5 volts, and opening point 10.0 volts. It will be noted that the opening voltage cold is slightly higher than that for the warm condition due possibly to the distortion of the base. This instrument was then put on 9-G3, and on the road test the closing point was found to be 15.8 to 16.0 volts, which is lower than the bench setting, as would be expected. GREEN LAMP SWITCH I. (12 G4) This instrument was set on the bench to close at 17.5 volts after being heated up on 17.5 volts. The rather higher voltage than in the cases of G and H was chosen on account of putting it into use on chassis 12-G4 with a higher output dynamo. On the bench the closing voltage cold was found to be 17.3. Contd. | ||