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How much detail do I need to include in the Product Description?

To help narrow down the design possibilities it is best if you can specify whether the part is a transformer or an inductor. Further more, it helps if you can identify what application the part is being used in. For example, some inductors may be used as common mode chokes and some transformers may be used as switch mode transformers. Knowing the application, helps select the proper core geometry and size.

Why do you need to know the operating frequency?

The operating frequency of any magnetic component is a key parameter. This helps the designer determine what possible core materials can be used on the design. It also helps determine the size of both the core and wire as well.

Do I need to include physical space limitations?

Including the physical parameters, especially dimensions that are constrained, are best to be highlighted. There is no guarantee that a design can be created to fit into some tight spaces, but knowing the limitations will help the designer select different geometries that support your highlighted constraints. Often times a compromise can be found.

What are special package requirements, give some examples?

Identifying the package/mounting options determines the type of bobbin or winding form that must be used. Situations where a PCB board is involved, the parts are either through-hole or surface mount. With other, stand alone transformers, flying leads or terminals can be used.

What is meant by operating mode?

Typically, specific type transformers, aka “switchers” not only operate in a frequency range, but also are used in a specific circuit topology. Operating mode describes how the transformer is used in the circuit; modes like flyback, forward converter, and bridge mode help define how to design the transformer. Specifying the operating mode is imperative, especially for switch mode type transformers.

Why do you need to know all the output voltages and currents?

When determining the size of a given transformer or inductor design, the amount of output power (the summation of all the output voltages and currents) is necessary to properly determine the overall size of the transformer.

Is it important to provide the input voltage?

Giving the input voltage details along with the output voltage helps the designer determine the turns-ratio that is needed for a given transformer. With this information, the designer can determine whether the secondary voltage needs to be stepped-down or stepped-up.

What is meant by Agency Requirements?

Often times a transformer or inductor is to be safety certified by a third party testing house. These safety consulting and certification type companies have standards and directives that key electrical components, such as transformers must meet. If the product to be designed is going to be in a power supply that is going to carry a UL or CE mark, it is best to know that up front. That way it can be determined what, if any, standards apply and how those translate to the insulation techniques and creepage requirements needed to meet those standards. Often times these requirements have significant impacts on shape and size of the magnetic component.


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