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).
The performance and specifications of a generator, regulator, and starting motor.
| Identifier | ExFiles\Box 23\2\ Scan072 | |
| Date | 4th November 1921 | |
| ROLLS-ROYCE - 4 - 4/11/21 10. PERFORMANCE: The 77 BR generator is designed to operate with our potential regulator, and this combination gives ideal battery charging performance. When the battery is fully charged, the current is low; when the battery is discharged, the current is high and the battery is quickly brought up to charge. The current decreases as the battery charges. The generator will carry 14 to 15 amps. continuously, when operating on the car, and generates 13 volts, 0 amps. at 475 R.P.M., which corresponds to a speed of 8 M.P.H. on a Rolls-Royce car. A current of 8 amps. at 13 volts is delivered to the battery at 750 R.P.M., or less, (12.5 M.P.H.). The maximum current delivered to a discharged battery is 12 to 15 amps., depending on the battery condition, and this tapers off to 3 1/2 to 4 amps. when battery is fully charged. The maximum efficiency is 65 %, and up to 30 or 35 M.P.H. we obtain an efficiency of better than 50%, for loads of 4 to 14 amps. This generator is so designed that a high efficiency is obtained for all load conditions. Our curves #102175 and 102176 show a comparison of the Smith and Westinghouse generators. Particular attention is called to the higher efficiency obtained with the Westinghouse generators throughout the speed range. The tests on the two machines were made in exactly the same manner, with all conditions being the same. The same test equipment was used for both tests, and both tests were made by the same man. 2. REGULATOR AND CUTOUT. 1. GENERAL: The potential regulator and cutout are combined in a single unit. The coils are wound on a three-legged magnetic core, and the complete unit, including windings, resistances, and condenser, are all mounted in a die cast aluminum box. Adjustments of both regulator and cutout are provided by fine threaded screws. This device is easily mounted on the dash, under the hood, where it is accessible. A full description of the operation, construction, etc. of this device, is contained in my letter to Mr. Olley, dated March 4th, 1921, and it is not necessary to repeat this here. 3. STARTING MOTOR. 1. GENERAL: The Westinghouse type 56 CG starting motor is 5" outside diameter, and weighs 20 lbs. 8 ounces. The windows are punched in the frame, and the general construction is similar to | ||