In this post we’ll provide brief introduction to different types of wires available for numerous magnetic applications:
This is the most commonly used wire, made of a round conducting section covered by an insulation layer.
The applications of enameled wires are widespread, serving as components for electromagnetic products, including building generators, motors, transformers, inductors, relays, measuring instruments, control, telecommunication equipments, and other electronic equipments.
Depending upon the underlying application, they are available in many insulation types, such as, polyester, polyurethane, polyester-amideimide and in many gauges.
Wire made of many thin wire strands, individually insulated and woven together in prescribed patterns.
It’s ease of use and having a very good AC resistance at high frequencies makes them well suited for high frequency transformers. Perhaps the biggest advantage that Litz wire can offer over any alternative is the reduction of AC losses due to skin effect. They also help in achieving least inductance-leakage as possible. However, as compared to rounded wire, they are quite expensive.
These are similar to round, but have a square section. They have good compacity due to it’s large conducting section.
Paper covered square wire has good mechanical properties and heat resistance and has been well received by both the local and international markets.
However, they have a very low AC resistance at high frequency and cost of fabrication is quite high as well.
The applications of paper covered rectangular wire is the principle type of conductor used for winding coils of transformers, welding machines, generators, and other electrical equipment. As such, these are similar to round, but have a rectangular section. They have good compacity due to it’s large conducting section.
Just like square wire, they have a bad AC resistance at high frequency and can be difficult to wind as well.
Copper foil inductors also offer several practical benefits for engineers and manufacturers. These include the following advantages:
- Size reduction – Windings made from copper foil optimize space.
- Temperature control – Copper foil dissipates heat more effectively than magnet wire.
- Reduced voltage stress – Copper foil facilitates a reduction in voltage stresses between the turns in the winding.
- More robust – Foil-wound components offer increased mechanical strength compared to wire-wound components
- Cost effective – Copper foil is much more affordable than Litz wire.
These are wires that are printed directly on a PCB, using external and internal layers when a low profile magnetic is needed. Manufacturers either use flat copper sheets or etch spiral patterns on a printed circuit board to form the “windings” of a planar transformer, replacing the turns of wire used to make other types.
Some planar transformers are commercially sold as discrete components, other planar transformers are etched directly into the main printed circuit board and only need a ferrite core to be attached over the PCB. A planar transformer can be thinner than other transformers, which is useful for low-profile applications or when several printed circuit boards are stacked. Almost all planar transformers use a ferrite planar core.
There are billions of possible combinations along the path towards designing the optimum magnetic element. When, additionally, different types of wires are introduced to the equation, the complexity of the problem can grow mind-numbingly large; especially because the usage boundaries and their trade-offs are not always clear.
At Shreejee Electronics, our team of expert engineers can assist you with the selection process, ensuring that you get the right materials for your design.