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).
Comparison of electrical characteristics between Watford EW6 and R.Bosch FU6R armatures.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan122 | |
| Date | 8th December 1924 | |
| ROLLS-ROYCE, LTD. INSTRUCTIONS. (2) To Order No. (WD{Mr Wood/Mr Whitehead}5 contd) Customer's No. | Watford EW6 armature | R.Bosch FU6R. Armature. | |----------------------------------|--------------------------------| | Secondary resistance | Secondary Resistance. | | 3280 ohms. at 20°C | 10140 ohms. at 20°C | | Secondary impedance (50~) | Secondary impedance | | 6010 ohms | 13050 ohms. | | Secondary inductance | Secondary inductance | | 15.8 henries | 25.4 henries. | It will be seen from these figures that the values of Resistance and inductance of the Bosch are considerably greater and nearly double those of the Watford. The Bosch armature is longer than the Watford and the iron section of the core as compared with an E06 core (which we believe is much the same as the EW6) is larger. Signed (contd) This Sheet must be filed on completion of the work. | ||