- Power and distribution transformers (7)
- Autotransformers, electric (power transformers) (1)
- Control transformers (2)
- Current limiting reactors, electrical (2)
- Distribution transformers, electric (8)
- Feeder voltage boosters (electric transformers) (1)
- Generator voltage regulators (1)
- Line voltage regulators (1)
- Power transformers, electric (3)
- Transmission and distribution voltage regulators (1)
- Voltage regulating transformers, electric power (6)
- Voltage regulators, transmission and distribution (2)
- Lamp ballasts (2)
- Specialty transformers (3)
- Electric furnace transformers (1)
- Lighting transformers, street and airport (1)
- Reactor transformers (1)
- Signaling transformers, electric (1)
- Toy transformers (1)
- Instrument transformers (except portable) (1)
- Vibrators, interrupter (2)
