Fundamentals

It is well known (but often forgotten) that the concept of inductance, without defining a complete loop of current, is completely meaningless! Some books give inductance of a length or wire, some people talk about the inductance of a via, and still others talk about the inductance of ground braids, etc. All these discussions about inductance ignore the requirement for a complete loop before the total or loop inductance can be discussed in any meaningful way.

Over the past several years, U.S. based organizations have curtailed traditional internal verification efforts due to reliance on contract manufacturers, distributors and suppliers to do the right thing. The inspection of ESD sensitive parts is very important, but without special safeguards, the additional handling to remove and repack a product for validation can cause both physical and ESD damage in the process. For parts, including those not sensitive to static electricity, measures must be utilized to detect, inspect and validate the packaging that identifies and protects the product.

A note from the Editor: In celebration of the 150th Anniversary of Maxwell’s Equations, we are honored to bring you a chapter from the book The Life of James Clerk Maxwell, the 1882 original biography of James Clerk Maxwell. This chapter, entitled “Faraday’s Lines of Force and Maxwell’s Theory of the Electromagnetic Field,” provides a unique insight to Maxwell’s theory of electromagnetic fields.