Did you ever came across cases where the contact material of the PCB connector was different from the contact material of the mating connector that the user was using unknowingly? What might happen if the PCB connector has gold plated contacts when the mating connector had tinned contacts?
That is a really interesting question. I must admit I have never come across a contact material issue other than how it relates to thermocouples. I don't believe I have ever seen terminal blocks (non-pluggable) with gold plating. Gold plating is available on pluggable connectors "for very small signals" (quote from a Weidmuller catalog).
IIRC I have seen a connector degrade as a result of oxidation during storage and as a result when installed the contact resistance was high enough to cause problems, but that has only happened once in over 20 years and was attributed to a production quality issue.
Mxing and matching terminal platings might be more a question for someone with electro-chemical or metalurgical knowledge- I certainly can only answer with "I don't know". I will see if I can find someone with an answer. I can say that with dissimilar metals you will get a thermocouple junction and there probably will be a uV source in series with the wire. This would not be that different to other metal junctions in the signal path- wire/connector or connector/solder.
I have a question regarding the contact material. Did you ever came across cases where the contact material of the PCB connector was different from the contact material of the mating connector that the user was using unknowingly? What might happen if the PCB connector has gold plated contacts when the mating connector had tinned contacts? A poor contact resistance and faster wear & tear? If the current is in the order of 20-30 mA, even then would there be reliability issues?
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Are the design challenges the same as with embedded systems, but with a little developer- and IT-skills added in? What do engineers need to know? Rick Merritt talks with two experts about the tools and best options for designing IoT devices in 2016. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.