Autotransformer Power Transformers
Last Updated: April 1, 2025
Description
An autotransformer is a type of transformer that uses a single continuous winding to serve both the primary and secondary functions. Unlike traditional transformers, which have separate primary and secondary windings, the autotransformer has a shared winding that allows for a direct electrical connection between the input and output. This design enables the autotransformer to adjust voltage levels efficiently.
Working Principle
The autotransformer operates on the principle of electromagnetic induction, similar to other transformers, but with a key difference: the primary and secondary windings are not electrically isolated. Instead, they share a portion of the same winding. This configuration allows for energy transfer through both conduction and induction. The shared winding results in a more compact and efficient design, making autotransformers particularly useful for applications requiring small voltage adjustments. The lack of electrical isolation, however, means that they are not suitable for all applications.
Applications
Autotransformers are commonly used in applications where electrical isolation is not a critical requirement. They are often employed to step voltages up or down in residential settings, such as converting 220-240 V to 110-120 V. They are also used in low power applications to connect circuits with different voltage classes, and in scenarios where adjustable voltage is needed, such as with variacs or variable transformers.
Advantages over other Power Transformers
Autotransformers offer several advantages over traditional two-winding transformers. They are generally cheaper to produce due to the reduced amount of copper and core material required. Their design allows them to deliver more power and operate more efficiently for the same physical size compared to two-winding transformers. This efficiency makes them particularly advantageous in applications where space and cost are significant considerations.
Limitations
One of the primary limitations of autotransformers is the lack of electrical isolation between the input and output. This can pose safety risks in certain applications, as it does not prevent electrical shocks or interference. Additionally, autotransformers are typically not suitable for high-power applications where electrical isolation is necessary.
Considerations
When considering the use of an autotransformer, several factors should be taken into account. The initial cost is generally lower than that of a traditional transformer, but this must be weighed against the potential safety risks due to the lack of isolation. Operating expenses are typically lower due to higher efficiency. However, durability and maintenance costs can vary depending on the specific application and environmental conditions. Autotransformers are generally accurate in voltage regulation, but care must be taken to ensure that the lack of isolation does not compromise the safety or functionality of the system.
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // 50KVA 100KVA 150KVA 200KVA 250KVA 300KVA 400KVA 450KVA 500KVA 20KV Oil Immersed Electrical Power Distribution Transformer [See More]
- Transformer Type: Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Oil; ONAF
- Construction: Laminate
from Triad Magnetics
Triad autotransformers are single winding transformers in which the primary coil is a fraction of the entire winding for voltage step-up or the secondary coil is a fraction of the entire winding for voltage step-down. In ordinary double wound power transformers, the primary and secondary are... [See More]
- Transformer Type: Autotransformer; Industrial Control Transformer; Isolation
- Output Voltage: 115
- Input Voltage: 277
- Secondary Current Rating: 1.3
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // Factory Price Resin Cast Dry Type Transformer 50KVA 100KVA 200KVA 315KV 400KVA 500KVA 600KVA Upto 2.5MVA 6.0KV 6.6KV 11KV [See More]
- Transformer Type: Autotransformer; Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Air; Fan cooling Natural cooling
- Construction: Laminate
from Triad Magnetics
Triad autotransformers are single winding transformers in which the primary coil is a fraction of the entire winding for voltage step-up or the secondary coil is a fraction of the entire winding for voltage step-down. In ordinary double wound power transformers, the primary and secondary are... [See More]
- Transformer Type: Autotransformer; Industrial Control Transformer; Isolation
- Output Voltage: 230
- Input Voltage: 115
- Secondary Current Rating: 4.35
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // Custom Transform Auto Transformers Electrical Power 380v to 220v [See More]
- Transformer Type: Autotransformer; Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Air; Fan cooling Natural cooling
- Construction: Laminate
from Triad Magnetics
Triad autotransformers are single winding transformers in which the primary coil is a fraction of the entire winding for voltage step-up or the secondary coil is a fraction of the entire winding for voltage step-down. In ordinary double wound power transformers, the primary and secondary are... [See More]
- Transformer Type: Autotransformer; Industrial Control Transformer; Isolation
- Output Voltage: 115
- Input Voltage: 230
- Secondary Current Rating: 0.4350
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // Customized 3 Phase Electrical 11kv 22kv 30kv 33kv Power 1000kva 1000kw MV &HV Distribution Power Oil Immersed Transformer [See More]
- Transformer Type: Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Oil; ONAF
- Construction: Laminate
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // SINCRON Outdoor 3 Phase Pole Mounted 11KV 33KV 50KVA 100KVA 200KVA 300KVA Oil Immersed Transformer [See More]
- Transformer Type: Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Oil; ONAF
- Construction: Laminate
from Shenzhen Xingkerong Technology Co., Ltd
Home // All Collections // Transformer // Durable Three Phase Oil Immersed Transformer 1000KVA 1500KVA 1600KVA Oil-immersed Power Transformer [See More]
- Transformer Type: Autotransformer; Distribution Transformer; Isolation; Power Transformer; Three Phase Transformers
- Mounting: Floor mounted
- Cooling Method: Oil; Fan cooling Natural cooling
- Construction: Laminate
from Acme Electric Corp. / Power Distribution Products
Acme's single phase transformers are design for use in industrial and commercial application. Transformers rated up to 25 kVA are enclosed within an encapsulated, NEMA 3R enclosures. Standard transformers rated from 37.5 to 250 kVA are enclosed in ventilated, NEMA 2 enclosures (optional... [See More]
- Transformer Type: Autotransformer; Power Transformer; Single Phase Transformer
- Primary Frequency: 60 Hz
- Cooling Method: Air
- Input Voltage: 240
from Toroid Corp. of Maryland
Optional enclosure with or without cord, plug and receptacle [See More]
- Transformer Type: Autotransformer
- Construction: Toroidal Core
- Mounting: Chassis; Dish/Disk
- Primary Frequency: 60 Hz
from Powertronix Inc.
3-Phase Auto Transformers offer a significant size and weight reduction as well as lower cost. Auto Transformers are for voltage step up or step down when there is no requirement for electrical isolation. APPLICATIONS. Automation. Marine [See More]
- Transformer Type: Autotransformer; Three Phase Transformers
- Power Rating (VA): 2000 to 120000
- Mounting: Flange, Potted in a Craddle
- Standards / Compliance: RoHS; UL
from Hubbell Incorporated
FREQUENCY RATING 50/60 HZ. POWER RATING 0.2 KVA. POWER RATING IN KVA .2. POWER RATING IN KVA - UOM KVA. PRIMARY VOLTAGE 200/220/240 VAC. SECONDARY VOLTAGE 115 VAC. TYPE AUTOTRANSFORMER. APPLICATION AIR CONDITIONING, REFRIGERATION. OUTPUT CURRENT RATING 1.74 AMPERE [See More]
- Transformer Type: Autotransformer; Power Transformer
- Input Voltage: 200 to 240
- Primary Frequency: 50 / 60 Hz
- Output Voltage: 115
from Electrocube, Inc.
High frequency, aluminum foil, copper foil, foil winding. Electrocube designs and manufactures hundreds of transformers and inductors using aluminum foil or copper foil in place of the standard copper wire used in conventional coil wire-wound transformers. This unique construction technology was... [See More]
- Transformer Type: Autotransformer; Isolation
- Power Rating (VA): 25 to 50000
- Input Voltage: 110 to 600
from Mirus International, Inc.
A 3-phase, low zero sequence impedance autotransformer, which when connected near to and in parallel with the harmonic generating non-linear loads (usually connected at the distribution panel), provides an alternate path for 3rd, 9th, & 15th current harmonics (triplens) which the loads create. [See More]
- Transformer Type: Autotransformer; Phase Shifting Autotransformer
- Input Voltage: 600
- Primary Frequency: 60 Hz
- Power Rating (VA): 750000
from Standex-Meder Electronics
TA-TAE-FPT Series Auto power transformers are line frequency magnetics designed in an open, enclosed package with an economical method of changing voltage levels. These auto transformers are widely used to operate electrical equipment outside of North America. Typically 50% smaller than similar... [See More]
- Transformer Type: Autotransformer
- Input Voltage: 115 to 230
- Primary Frequency: 50 / 60 Hz
- Output Voltage: 115 to 230
from GE Grid Solutions
Transformers. GE offers a wide range of transformer solutions for the utility, industrial, commercial, residential, and energy markets. These products & solutions feature flexible, reliable, and robust designs to support a wide range of applications. With units operating in some of the most... [See More]
- Transformer Type: Autotransformer; Encapsulated Coil Transformer; Distribution Transformer; High Voltage Transformer; Power Transformer; Rectifier Transformer; Substation Transformer
- Mounting: Chassis; Pad-Mounted; Pole Mounted
- Cooling Method: Air; Oil
from Block USA, Inc.
Rated input voltage 115/220/230/240 Vac. Rated output voltage 115/220/230/240 Vac. Rated output voltage 0.8 - 16 A. Insulation class A or B. Maximum ambient temperature 40 °C. Degree of protection IP 20. Autotransformer. to: VDE 0570 Part 2-13, DIN EN 61558-2-13, EN 61558-2-13,. IEC 61558-2-13. [See More]
- Transformer Type: Autotransformer; Encapsulated Transformers
- Output Voltage: 115 to 240
- Input Voltage: 115 to 240
from Acme Electric Corp. / Power Distribution Products
Acme ’s low voltage distribution transformers are designed for industrial and commercial applications. All of Acme ’s general purpose transformers are rated for 600 volts and below. Encapsulated units are offered in ratings up to 15kVA. Ventilated units are available in ratings up to... [See More]
- Transformer Type: Autotransformer; Power Transformer; Three Phase Transformers
- Mounting: Pad-Mounted
- Cooling Method: Air
- Primary Frequency: 60 Hz; 50 / 60 Hz
from Powertronix Inc.
Auto Transformers are single winding toroidal transformers for voltage step up or step down, when there is no requirement for electrical isolation. Auto Transformers offer a significant size and weight reduction as well as lower cost. APPLICATIONS. Industrial Automation. Electrical Equipment [See More]
- Transformer Type: Autotransformer; Single Phase Transformer
- Construction: Toroidal Core
- Mounting: Center Potted with Thru Hole, Flange, Excapsulated, Custom Mounting Bracket
- Input Voltage: 120
from Hubbell Incorporated
APPROVAL UL, CSA. ENCLOSURE ENCAPSULATED. FREQUENCY RATING 60 HZ. MOUNTING WALL. NUMBER OF PHASES 1. POWER RATING 1 KVA. POWER RATING IN KVA 1. POWER RATING IN KVA - UOM KVA. PRIMARY VOLTAGE 240 VAC. SECONDARY VOLTAGE 120/240 VAC. TYPE AUTOTRANSFORMER, DISTRIBUTION, DRY [See More]
- Transformer Type: Autotransformer; Power Transformer
- Primary Frequency: 60 Hz
- Mounting: Wall Mounted
- Input Voltage: 240
from Mirus International, Inc.
Designed to replace standard drive isolation transformers, the Drive Tamer ™ is built to not only withstand the harsh harmonic environment produced by Variable Frequency Drives (VFD) but to also induce cancellation of harmonics upstream and thereby reduce voltage distortion throughout the... [See More]
- Transformer Type: Autotransformer; Phase Shifting Autotransformer
- Input Voltage: 600
- Primary Frequency: 50 / 60 Hz
- Power Rating (VA): 660000
from Block USA, Inc.
Rated input voltage 3 x 200/208 - 3 x 690 Vac. Rated output voltage 3 x 400 Vac. Rated power 2000 - 250000 VA. Insulation class F. Maximum ambient temperature 40 °C. Efficiency up to 98 %. Degree of protection IP 00/23/54. Optionally adapted package for higher degrees of protection. [See More]
- Transformer Type: Autotransformer
- Output Voltage: 400
- Input Voltage: 200 to 208
- Power Rating (VA): 10000
from Block USA, Inc.
Rated input voltage 3 x 400 Vac. Rated output voltage 3 x 130 - 3 x 240 Vac (5 stages). Rated current 3 x 1.5 - 3 x 15 A. Insulation class E. Maximum ambient temperature 40 °C. Degree of protection IP 00. Autotransformer. to: VDE 0570 Teil 2-13, DIN EN 61558-2-13, EN 61558-2-13, IEC 61558-2-13. [See More]
- Transformer Type: Autotransformer
- Output Voltage: 130 to 240
- Input Voltage: 400
from Block USA, Inc.
Rated input voltage 230 Vac. Rated output voltage 110 Vac. Rated power 250 - 1000 VA. Insulation class A. Maximum ambient temperature 40 °C. Efficiency up to 96 %. Degree of protection IP 22. Autotransformer. to: VDE 0570 Part 2-13, DIN EN 61558-2-13, EN 61558-2-13,. IEC 61558-2-13. [See More]
- Transformer Type: Autotransformer; Encapsulated Transformers
- Output Voltage: 110
- Input Voltage: 230
- Power Rating (VA): 1000
from Block USA, Inc.
Rated input voltage 230 or 400 Vac. Rated output voltage 80 - 310 Vac. Rated output voltage 0.8 - 18 A. Insulation class B. Maximum ambient temperature 40 °C. Degree of protection IP 00. Autotransformer. to: VDE 0570 Teil 2-13, DIN EN 61558-2-13, EN 61558-2-13, IEC 61558-2-13. Autotransformer... [See More]
- Transformer Type: Autotransformer
- Output Voltage: 80 to 190
- Input Voltage: 230
from Block USA, Inc.
Rated input voltage 110 Vac. Rated output voltage 230 Vac. Rated power 250 - 1000 VA. Insulation class A. Maximum ambient temperature 40 °C. Efficiency up to 96 %. Degree of protection IP 22. Autotransformer. to: VDE 0570 Part 2-13, DIN EN 61558-2-13, EN 61558-2-13,. IEC 61558-2-13. [See More]
- Transformer Type: Autotransformer; Encapsulated Transformers
- Output Voltage: 230
- Input Voltage: 110
- Power Rating (VA): 1000
from Block USA, Inc.
Input rated voltage 3 x 690 Vac. Output rated voltage 3 x 400 Vac. Rated power 650 - 1386 VA. Ambient temperature +60 ° C. Protection index IP 00. Autotransformer. to: VDE 0570 Part 2-13, DIN EN 61558-2-13, EN 61558-2-13,. IEC 61558-2-13. Matching transformers to adjust the supply voltage of... [See More]
- Transformer Type: Autotransformer
- Output Voltage: 400
- Input Voltage: 690
- Power Rating (VA): 650
from Block USA, Inc.
Rated input voltage 110/125/230/240 Vac. Rated output voltage 110/125/230/240 Vac. Rated power 150 - 3000 VA. Insulation class B or E. Maximum ambient temperature 40 °C. Degree of protection IP 00. Autotransformer. to: VDE 0570 Teil 2-13, DIN EN 61558-2-13, EN 61558-2-13, IEC 61558-2-13, UL... [See More]
- Transformer Type: Autotransformer
- Output Voltage: 110 to 240
- Input Voltage: 110 to 240
- Power Rating (VA): 1000
from Block USA, Inc.
Rated input voltage 230 Vac. Rated output voltage 0 - 250 Vac. Rated current 0.8 - 20 A. Insulation class B. Maximum ambient temperature 45 °C. Degree of protection IP 00. Variable transformer. to: VDE 0552. Variable auto transformer for continuous adjustment of AC voltages or currents under... [See More]
- Transformer Type: Autotransformer
- Output Voltage: 230 to 250
- Input Voltage: 230