I already have 3 lounge posts going.. why not a forth??

I have TONS of old electronics that have all passed away.. or that I have just broken for wire or something stupid like that. Well, there are probably 1 million resistors in that mess of crap, along with tons of caps, transistors, switches.. the works. I know I would be dealing with less of wire to solder to my board.. but I am sure for the cost of all the stuff [Free], that I could deal with it.

The caps have their uF and rated voltage printed on them, so that'* a no brainer. But the diodes aren't identified.. or at least not all of them.. especially not the switching diodes. So, how can I tell what kind they are? Resistors have the colour coding, however I don't fully understand it. I believe I am correct on the colour coding.

First and second colour band
Black = 0
Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Violet = 7
Gray = 8
White = 9

Third colour band
Black x 1
Brown x 10
Red x 100
Orange x 1,000
Yellow x 10,000
Green x 100,000
Blue x 1,000,000
Silver / 100
Gold / 10

And then there is the forth colour band.. which I don't know for sure.. but I wrote them down somewhere. Am I correct? I am not the greatest at remembering things, so please correct me on those, if I am wrong.

So, is it worth it? Remember I wouldn't be able to afford these things, but since I have them.. I could spend a day just de-solding them all, and organizing them all. I think it wouldn't be that bad of an idea.


-justin

You have the resistors figured out pretty well. The fourth band is a tollerance value. I'm not entirely sure what they are but I think gold is +/-5% and silver is +/-10%.

You sound like me... a packrat. I usually keep stuff for years, trip over it all the time and shortly after I throw it out... I need it.

Yep! I have a box filled with crap, that i am always tripping over. I have another box filled with at least 10 blown motherboards.. and guess what? They too are in the way of getting to my "computer area" in my basement.

I looked over my cheat sheet, and you are correct on the forth band. Gold = 5% tolerance, Silver = 10% tolerance and no band = 20% tolerance.

I was looking at one of my boards, and it does have some writing on the diodes.. but the cylinder shaped ones.. but not the other kind.. they are like flat on one end, and are like the top of a hexagon on the other.. it'* hard to explain. But anyways those don't have any writing. How can I tell what kind of diode it is? Like I previously mentioned, I would never be able to tell the switching diodes like the 1N4148 I think it is.. because it'* so small.


-justin

I only know of 2 types of diodes: Zener and regular. A Zener diode is usually orange and black. The regular diodes have a marking on them that looks something like this: ---->|---- . The triangle is the positive side and the line is the negative side. The regular diodes will have different diameters that indicate the wattage rating. Similar to 1/4 and 1/2 watt resistors.

yea yea yea! That'* it, the Zener diodes.. those ones, how can I tell what kind they are? The regular ones have a model number on them.. that would take 10 seconds for me to find the specs on, so that'* good too. What are Zener diodes used for? Like do they have a special purpose other than dioding? loL Or are they just a prettier form of diode that make circuit boards all the more complex looking?


-justin

It'* been a long time since I learned about them. I believe they are used for very precise voltage regulation. CPUs, sensitive measuring devices, etc. I have no idea what, if any, difference there are between them.

Give it a Google and see what you can dig up. You've got me curious now.

http://hyperphysics.phy-astr.gsu.edu...ids/zener.html

You are correct, everything I pulled up, had to do with accuracy, in that Zener Diodes hold their voltages, with very little tolerences [from 20% to 0.05%]. Sounds like you are correct my friend


-justin

Huh, not too bad for an old fart. I took some elecrtonics courses back in '89.

That seems like forever ago.

Not that bad, it was the year my baby was built


-justin