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).
Experimental method for motor testing, including a circuit diagram.
| Identifier | ExFiles\Box 34\3\ Scan116 | |
| Date | 15th February 1916 | |
| -2- [Circuit Diagram Text] Mains from generator. Reverse current Cut Out Var. resistance. Central Zero ammeter Two Var. Res's in parallel. Two Var. Res's in parallel. It will be seen that armature and fields of motor are supplied independently, each through its own ammeter and a couple of variable resistances in parallel. So we could get a fine adjustment of each current. Our method was as follows :- We kept a fixed excitation of the driving motor throughout the experiments, and a fixed speed. This was 1500 R.P.M forwthe starter motor, and 768 R.P.M. for the driving motor. We used a Hasler Revolution Counter and found this speed ratio to remain very correct until the load became so great (see later) as to cause belt creep. For this fixed speed and excitation of the driving motor, we could observe the armature volts and amperes for various loads, and upon plotting these and producing the curve backwards, we could obtain the voltage of the motor armature corresponding to zero armature (Contd)! | ||