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Topic: Feasibility of measuring large DC current with Arduino (Read 4356 times) previous topic - next topic

jackrae

You'll often seen multi-pronged
wipers on switches and potentiometers for this reason, since if one contact point corrodes the other
still has a low resistance and prevents further damage on the corroded one.
Whilst that may well be the case, the real reason for using multi-contact wipers on switching devices is to permit good contact distribution with controlled minimal pressure since a single solid (inflexible) contact wiper surface must inevitably give poorer current distribution as no two sliding surfaces will ever be in perfect contact.  As an analogy a brush head with bristles is much better at sweeping than a solid wooden brush head

JohnDeere630

........As an analogy a brush head with bristles is much better at sweeping than a solid wooden brush head
LOL, I have to remember that one! That pretty much sums up my day, on occasion. Eating soup with a fork is another saying I use; you stay busy, but don't accomplish much.

I don't remember all the details of the incident I was referring to. It was a very, very large bank of 2 volt batteries, on the order of 40k a/h at a biomass powerplant. I was just a helper on another crew and remember asking about the show. I have no idea why such a small cable was anywhere near such a large bank. When it was finished, it was all big copper bars that connected everything.

JohnDeere630

MCP6002 has 2 amps on the one 8 pin chip, you only need one thus "1/2 MCP6002" it can be had with 1, 2 or 4 amps per chip as MCP6001,2 and4.
BTW since the old timers here seem to know a lot more than me it would be best to listen to them.
Gotcha. I have a couple of things I plan to try. All approaches I would not have know about without you folks. Thanks a bunch to all of you that answered!

Gary

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