Trying to get information on this Westinghouse Electric & Mfg Co. Potential Regulator, primarily what it is, what it was used for, it’s age and value (if any). I believe it to be used late 1890-early 1910 timeframe. Home use? Industrial use? Potential value?

Nameplate data:
Westinghouse Electric & Mfg Co.
Potential Regulator.
Type AA-1
For AC Generators
Style # 226080
Ser # 242924
2920 12-15-13