SX460 is a half-wave phase-controlled thyristor type Automatic Voltage Regulator(AVR) and forms part of the excitation system for a brushless alternator.
Technical specification
Input
       Voltage         Jumper selectable 95-132V ac or 190-264V ac
       Frequency     50-60Hz nominal
Output
       Voltage         Max 90V dc at 207V ac input
       Current         Continuous 4A dc
                            Intermittent 6A for 10 secs
       Resistance     15 ohms minimum
Regulation   +/-1.0%