corroded copper hookup wire?
agimuhing
Posts: 39
I have a propeller chip on a breadboard. when I powered it up recently, it wouldn't do anything. I later measured its power rail and found out that 1 volt was missing. I measured the regulator and it was outputting 3.3V.
I am sure that everything is wired up correctly because I have gotten it to work intermittently.
The breadboard was wired up with bare copper hookup wire I cut more than six months ago
Do hookup wires corrode enough in six months to cause a 1 volt drop?
I am sure that everything is wired up correctly because I have gotten it to work intermittently.
The breadboard was wired up with bare copper hookup wire I cut more than six months ago
Do hookup wires corrode enough in six months to cause a 1 volt drop?
Comments
Unless you have it immersed in acid, it's very unlikely you would see any corrosion of that magnitude. But this does sound very much like a bad connection somewhere. If you used bare copper wires, what are the chances that two wires are touching? It's better to use insulated wire, of course, and to keep your connections as short as possible. If you want, you could post a photo of your breadboard and we might see something odd going on.
It's also possible you could have a blown bypass capacitor or something.
My 2 cents.
works fine now and the voltage at the prop power pins is back to 3.3
Sweat from your fingers is the acid, and yes it will corrode copper in a few months quite happily (just leave a fingerprint on a clean copper-clad circuit board for example). Acids in the atmosphere increase the problem and if the copper gets at all damp then verdigris (copper carbonate) will form (its green and is often a feature of copper sheet roofing). This is why electrical hookup wire is usually tinned copper wire, as tin is much more inert to atmospheric and sweat attack.
Bare copper wire should be soldered or connected with a screw-terminal.
Some copper oxides act as a semiconductor and can rectify if in contact with a different metal. Another reason to tin it.
[edit: and clean totally oxide-free copper is salmon pink in colour - not copper-coloured!]
These may require a jumper to make them continuous.
BTW, I use the 8 strand telephone wire, the stuff used installed behind the walls, for hookup wire on my plugboards.
Its really cheap in 100' reals, that's 800'.
This wire has a relatively hard plastic insulation and strips easily.
Duane
Also, some foks have LOTS of acid in their fingers. I had a friend who played guitar with me, and used the same Ernie Ball lights, and he would practically dissolve the strings off the guitar. He went through strings about four times faster than I did.
Now I sometimes use latex gloves or finger cots when I'm working on projects that are tricky or touchy.
possible. This will afford a better connection as the spring tension is less
when using the adjacent holes.
Some of the breadboards were designed to have separate contact springs, but most are
a long bar of spring material and the problem shows on that type easily.
jr