Swallow SC21-200E is a single-phase, electrostatic-shielded power transformer rated at 200 VA, designed to convert 200/220 V mains to 100/110 V control voltages. The primary winding accepts 0–200 V or 220 V, while the secondary provides 0, 100 V and 110 V with an E terminal for the shield (0/E on the secondary). It uses a screw-up terminal block with M4 screws for secure connections and weighs about 4.2 kg. Typical applications include supplying control circuitry or testing equipment in industrial settings that require a shielded, lower-voltage supply from a 200–220 V source.
