Main Features of Coaxial Transformers
Exceptional Magnetic Coupling
The coaxial design of the shotgun transformer ensures superior magnetic coupling between the primary and secondary windings. The use of a copper tube for the secondary winding confines the magnetic field of the primary winding within the tube. This significantly benefits topologies that demand excellent magnetic connectivity between windings.
High Current Handling
The naturally large cross-sectional area of the copper tube, combined with its substantial surface area, allows coaxial transformers to handle extremely high currents efficiently. This makes them suitable for applications requiring robust current capabilities.
Controllable Magnetic Saturation
Unlike conventional transformers that experience abrupt saturation leading to potential degradation of semiconductors, coaxial (or shotgun) transformers feature a more controlled saturation profile. By incorporating two powdered toroids into the core stack, the transformer softens the saturation curve. When the ferrite cores reach saturation and temporarily lose their magnetic properties, the powdered cores maintain magnetic functionality, providing critical microseconds for the system to respond. This feature protects semiconductors from excessive current and ensures stable device operation.
Compact Form Factor
Coaxial transformers offer a higher power-to-volume ratio compared to conventional designs. Additionally, their ability to integrate a synchronous rectifier within the transformer structure further enhances power density, making them ideal for applications with space constraints.