Power Distribution II Signal Contacts in Parallel This is the final article in our series about the distribution of current in power applications. In the previous article in this series, the topic was distribution of current using dedicated high current, several tens of amperes, contacts.  This article will address the use of multiple signal—low current,Read More

Power Contacts and Connectors Part 1: Power Distribution Today, there are three different approaches to power distribution in connectors, particularly, on current distribution. They include individual high-current contacts, multiple low-current contacts in parallel, and hybrids, which use both approaches in the same housing. Each approach has its advantages and limitations. Let’s begin with high-current contacts,Read More

Power Contacts/Connectors Part III: Current Rating 2 This week, let’s examine the current rating test program, which includes the measurements to be made and the conditioning and exposures to be applied in connector testing. Figure 1 includes an example program. A program of this general nature is under consideration in ECA CE-2.0 National Connector andRead More

Power Contacts/Connectors Part III: Current Rating 1 A number of issues need resolution in order to perform a current rating test program. Both practical and philosophical issues should be taken into consideration as you embark on this process. We first discuss the practical issues. The relevant document for this discussion is EIA 364 D: TP-70B,Read More

Power Contacts/Connectors Part II: Current Concerns Before we begin discussing current rating, let’s define the types of current a contact or connector may carry. There are four different current types: Transient, overload, steady state, and intermittent, also called duty cycle, currents. Figure 1 illustrates the first three current types in an induction motor application. RegionRead More

Power Contacts and Connectors Part I: What is Power? Understanding power is critical to the design of power contacts and connectors. By presenting a six-part series exploring these specialty contacts, I hope to empower you to make the best design decisions the next time you embark on a project. We’ll begin by defining what isRead More

Dr. Bob Relates Connector Degradation Mechanisms to Connector Testing New Connector Series Begins The last article on loss of contact normal force completed the series on connector degradation mechanisms. (For completeness, the series included an introductory discussion of degradation mechanisms, two articles on corrosion—one on fretting corrosion and one on corrosion in noble metal contacts—anRead More

Degradation Mechanisms – Loss in contact normal force In the previous article on wear as a degradation mechanism, I noted that wear is an indirect degradation mechanism. Wear of the contact finish, if it exposes the underlying base metal of the contact spring, introduces additional sources of corrosion directly at the contact interface. Similar commentsRead More

Connector Degradation Mechanisms – Wear This is the fourth article in a series on connector degradation mechanism, and it addresses connector wear mechanisms and processes. The previous three articles in this series discussed corrosion as a connector degradation mechanism; fretting corrosion in the case of tin contact finishes and general corrosion due to exposed baseRead More

Connector Basics: Connector Degradation Mechanisms—Corrosion Part II This is the third article in a series on connector degradation mechanisms and the second article focused on corrosion. Tin-to-tin contact interfaces and fretting corrosion, as the dominant degradation mechanism in such systems, was the focus of the previous article. Now, we will address corrosion effects on contactRead More

Connector Basics: Connector Degradation Mechanisms—Corrosion Part I This is the second article in a series on connector degradation mechanisms. Corrosion, in general terms, followed by a discussion of a particular corrosion mechanism, fretting corrosion, will be the focus of this piece. Last month, we studied the asperity or a-spot model of a contact interface. InRead More