***Official Electronics Thread of Officialness (it starts off with lots of Nixie Tube Clock goodness

  • Thread starter Thread starter Aod
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Feek said:
Dalo pen and ferric chloride always used to be the way to make PCBs when I was a lad. Just be careful with the ferric chloride, it's nasty stuff.
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I have considered that, seems a pretty complex circuit to draw by hand though? The problem here seems to be the lack of any reference for size.

Tefal said:
build this with strip board


http://lab.guilhermemartins.net/2009/05/06/paperduino-prints/
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Interesting... not sure how the lack of Serial/USB connection would work out though? I've come across a few simple protoboard designs but they all seem to require already having a complete Arduino so you can program the chip and drop it in.
 
Nate Silvers said:
Wait I thought if you solder a capacitor the wrong way around it will blow that's why they have the short leg and the negative strip down one side.
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those are the polarity indicators, yes, but a capacitor that isn't correctly installed is unlikely to explode, but the circuit simply won't work :)

PhillyDee said:
Thats just visual cues so you put it around the correct way. I once blew up a rather large PSU cap. Was a 63V 3000uF monster. I really did nearly crap myself!
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Niiiiice!
 
Yeah, it was about the size of a C cell battery. I thought that the cap exploding was why the PSU failed. So I replaced them both. Turns out that the cap failed due to a PSU fault. So it blew again. Amazing how much electrolyte can coat in a gooey mess!
 
Aod said:
highly unlikely, Caps only blow if they're really badly mistreated. what's much more likely is that it just won't work :p
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Exactly. They're very difficult to kill :)

One of the best ones I've seen was on a potter's wheel of all things. The wheel ran out of control because some kid bust the switch (which was effectively a dimmer circuit), and the main capacitor (think larger than 35mm film pot size) on the motor run board went bang, and fired the plastic cover up so high that it hit the ceiling of the theatre hall it was in :D
 
Many years ago I worked in a factory for about nine months and I soldered all day every day (it's where I really learned to solder) and every few weeks we'd hear a huge bang from one end of the building - It was the QC department and that bang generally meant that someone had fitted a large electrolytic backwards. A cheer always went up :)
 
Feek said:
Dalo pen and ferric chloride always used to be the way to make PCBs when I was a lad. Just be careful with the ferric chloride, it's nasty stuff.
Click to expand...

At work, we etch our own prototype boards. Ferric Chloride is horrid, I can attest to this. Just by inhaling the tiniest amount of fumes you'll have an iron-like taste in your mouth for a while, just like the taste you get from a nosebleed. It stains everything and irritates your skin. However it's pretty much essential to the process so you just have to grin and bear it. :rolleyes:
 
Just aluminium foil. They're further away than Copper and Zinc in terms of reactivity anyway. The electrolyte is pieces of kitchen roll soaked in a vinegar-salt solution, and it's a stack of 10 in all. Took it from the dangerous book for boys and improvised a bit :p
 
Right, I have a small problem. Can anyone tell me whether these caps are polar/non-polar, and which end is which polarity (if polar?). I'm replacing the red ones with the gold ones:

Wima.jpg


ObbligatoCaps.jpg


The above are just example images of capacitors of the same series, so ignore the values. The text layout/markings are otherwise identical. The gold caps have no markings on apart from the text/rating info. Both ends are black.
 
Really? :o

It's just that I saw a photo of the amp they're going into on Headfi with polar caps in (the leads were black and red). I only went and sent an email to the supplier asking them too. :o

Cheers for the info. :)
 
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