Toroidal transformers are built around a ring-shaped core, which, depending on operating frequency, is made from a long strip of silicon steel or permalloy wound into a coil, powdered iron, or ferrite. Toroidal transformers are more efficient than the cheaper laminated E-I types for a similar power level. Other advantages compared to E-I types, include smaller size (about half), lower weight (about half), less mechanical hum (making them superior in audio amplifiers), lower exterior magnetic field (about one tenth), low off-load losses (making them more efficient in standby circuits), single-bolt mounting, and greater choice of shapes.

Application:
This kind of toroidal transformer is widely used in electronic equipment and other electronic equipment of higher technical requirements, such as computer, medical equipment, telecommunications and lighting and so on.

Material
Core: High quality cold grain silicon sheets inserted by machine, annealed by advanced vacuum annealing furnaces to improve electronic data
Bobbin: Excellent Anti-combustion
Wire Materials:
1. Copper, Aluminum, Aluminum Clad Copper.
2. The size of transformer total in Aluminum is larger than which total in Copper.
3. Aluminum instead of Copper Cost Save: 13%-35%/PCg

Advantages of toroidal transformers
Efficiency
Smaller in size
Lower in weight
Less mechanical hum
Low exterior magnetic field
Low off load losses
Single mounting point

Operating environment
1)Temp.: The ambient temperature can not over +40degree Celsius
2)Altitude: Mounting location can not exceed the altitude of 2000m
3)Relative humidity: Maximum 90%
4)The site not attack by rain and snow
5)The medium which no explosion danger, no corroding metal, no electrical breakdown

Testing Items:
No-load Test(No-load Current, No-load Voltage, No-load Loss)
Load Test (Load Voltage, Temperature-rise)
Inductive Voltage Test
DC Resistance Test
Safety Test

Warning
Under no circumstances should both ends of the fixing bolt simultaneously contact the metal chassis or framework as this would create a potentially dangerous 'shorted-turn'.

Certificate
The certificate of our transformer has CE CQC RoHS UL

Note
The above-mentioned toroidal transformer is frequently-used, we can also manufacture the products by customer design. And the specification is for reference, if has the change further, please take the material object as the standard.