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 operating voltage tests for temperature-compensated auto and green lamp switches.
| Identifier | ExFiles\Box 59\1\ Scan348 | |
| Date | 27th June 1929 | |
| X4008 27.6.29. SUMMARY OF DETAILS OF OPERATING VOLTAGES OF TEMPERATURE COMPENSATED AUTO AND GREEN LAMP SWITCHES AUTO SWITCH B. 8-EX. This instrument, tested on the road 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. After running 10,000 miles and being removed from car it was bench tested and found to open at 15.0 volts and close at 12.5 volts, thus showing reasonable consistency of setting. GREEN LAMP SWITCH G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 12-EX. 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. Replaced on 12-EX. Tested on road 19.3.29 after 17,000 miles. Found to close at 16.1 volts (at switchbox). System maximum 17.4 volts (hot), 18.0 volts (cold). Re-set to close at 17.0 volts. Road test 6.5.29 after 18,200 miles. Closing at 16.5 volts (at switchbox). System maximum 17.8 volts later, system maximum 17.0 volts due to warming of battery. GREEN LAMP SWITCH H.{Arthur M. Hanbury - Head Complaints} 9-G3. This instrument was, as in the case of G, set to close at 16.8 volts after being heated up to 16.8 volts. | ||