All for Want of a Connector.......

I had a customer recently, PeopleNet,  that develops Hardware and Software for Over the Road Trucking applications.  As I'm sure that you're aware, Telematics and Transportation are quickly converging on our highways. Cars and Trucks are becoming smarter and more autonomous.

I was asked to review and improve the design of a handheld tablet and docking system that was suffering from frequent disconnects while in the field.  The initial design had been based on the use of a poorly designed pogo pin style connector that linked the tablet to the dock.

A pogo style contact gets its name from the pogo stick toy that we used as children.  It relies on a plunger coated with Gold to make the electrical interface to the tablet.  The plunger, in turn, is pressed upon by a compressed spring to apply force.

Simple right? Not really.  What is created is a the electrical equivalent of a shock absorber. If the tablet moves , the contact must follow its motion with virtually no error.  If not, electrical discontinuities (shorts) appear in the communication link.

Software communication protocols have different levels of interrupt tolerance. In the customer's case, they were shipping USB 2.0. Not the fastest form of comm. - but also not the slowest.

After reviewing the overall mechanical design, I was convinced that the electrical connector had several mechanical issues ranging from minimal Gold plating to overly large assembly tolerances.  They simply were not going to build a reliable dock using the current connector.  I recommended a higher reliability connector that would have increased system cost by approx. 15 percent.

The customer was hesitant, even though they were spending significant amounts on retrofits, service calls and reputation. This was over the course of a 2 year period.

A connector is a critical design element in any system.  Marginalize it, trivialize it and you will pay so  much more in the long run.