| Popis: |
TO SUPPLY power to certain types of shipboard instruments, a source of alternating current is required in which the frequency error must be ±0.1 per cent or less over a range of temperatures, loads, and supply voltages. This need has been met by the use of small motor-driven alternators which run on the ship's d-c power supply. Frequency regulation is accomplished by shunt-field current control in the motor, and the field current is controlled by some form of servomechanism and frequency-sensing device. |
