# I cant figure out what these are.



## TheDragonWins (May 9, 2016)

What are these black things that are running down the middle of this board.






Are these little Yellow Capacitors tantalum? Are they worth pulling?





These Yellow things that say AM on them happen to be a very reflective film about 25 feet long, tightly bound. Im just curious if anyone has processed them





WHen a contact material is listed as Gold over SIlver, does anyone know the ratio? example would be the NF series of relays made by Aromat Japan


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## Topher_osAUrus (May 9, 2016)

http://www.uchobby.com/index.php/2007/07/15/identifying-electronic-components/

That website may give you a decent guideline of what the codes on the circuit board may be.

That is the best I can do. I only dealt with escrap for a little bit and have been trying to forget about it. To me it was a nightmare. But, those boards do look like ones i encountered.

I just removed everything and then separated them into their "like piles".

Im sure one of our electronics guru's will give you much more detailed information very soon though.


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## g_axelsson (May 9, 2016)

First picture... black things are ferrite inductors, basically a copper wire in the center and iron oxide ceramic black part. Protects from radio frequency interference signals.

Second picture, small yellow capacitors are probably MLCC:s with wires. Down in the right bottom corner is a bigger tantalum capacitors with one side cut at an angle to show polarity.

Third picture, long reflective film, aluminum film capacitor. It might (big question mark here) contain some silver braze where the pins make contact with the aluminum foil, but probably not. Test it with a drop of nitric first and then with some chloride (table salt or HCl) to spot any silver chloride created. Easy test to do.

Gold over silver often means gold plate on silver base. Think thick plating, 2-3 times as thick as circuit board fingers, any thinner would have problem with diffusion.
As gold over silver is used only at small current signals it usually only occurs on smaller relays. The small size of the relay contacts makes it more of a nice thing to watch rather than a good source of gold. You need a lot of relays before the gold starts to add up, but perfect to use for inquarting, you get the separation of the gold from the silver for free.

Göran


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## TheDragonWins (May 9, 2016)

Thank you for the answer to question number 1 I've been wondering that for a while. What does the L on the board designate? Also, relay's were rather expencive when they were available, so expencive to the point that they were discontinued simply do to extremely low sales and a cheaper replacement. 


Contact Material Gold-clad silver


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## g_axelsson (May 9, 2016)

The L is traditional for denoting inductance in electronics. It is used in equations for inductance and probably goes back to when electrical circuits were new. One of the pioneers in this area was Heinrich Lenz (1804-1865) who formulated Lenz law for inductors and that is probably the origin of the L for induction.

https://en.wikipedia.org/wiki/Inductor

Göran


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## UncleBenBen (May 9, 2016)

Try a Google search for "refdes". Short for reference designation or something along those lines. You will find many lists of PCB markings and codes.

Some you will have to take an educated guess at from time to time. Each manufacturer, and each factory for the manufacturer will come up with their own occasionally to suit production needs.


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## johnny309 (May 11, 2016)

In the third picture ...you have :
On the left a IC(the black package)......contains Au ...in a form of wires and solder
On the right is an resistor array(the yellow package).... contains Ag-Pd


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