Discussion thread regarding Schematics for the Constant Wattage [CW] and the Regulated Lag [Reg-Lag] type Isolation Transformer Ballasts, using High Pressure Sodium [HPS] or Metal Halide [MH] lamps.
These Schematics are found in the Technical Reference Area, under the topic heading: HID Ballasts Schematics: CW / Reg-Lag
Fig. 4.3.= Constant Wattage Isolation Transformer Ballast with multi tapped primary,
Fig 5.1. = Regulated Lag Isolation Transformer Ballast with multi tapped primary.
Both can be used with High Pressure Sodium lamps, or "Pulse Start" type Metal Halide lamps.
Both have multi input voltage capabilities, which do not require the common conductor to be the system's grounded conductor - due to the Isolation of primary from secondary windings.