Component Identification? What are these?

[eccerr0r]

I pulled these from somewhere a long time ago and never took a look at what they were. It's too bad that I didn't study the board they came out of, but the board's long gone... anyway, now I wonder if anyone knows what these are...

When I put an ohmmeter across them they're open both ways. I suspect they're kind of broken but maybe they're nonlinear...

[trebo]

Re: Component Identification? What are these?

could be zenner diodes,at a guess

[Blargh523]

Re: Component Identification? What are these?

could be zenner diodes,at a guess

That would be my guess as well. I'm just not used to seeing color-bands on through-hole ones.

And good luck figuring out value, AFAIK, manufacturer's didn't really have a standard -- the colors don't translate directly to a voltage value, but to a part number on a look-up sheet -- which is why in most cases color-coded diodes have been replaced with ones with part numbers on them.

[Phaihn]

Re: Component Identification? What are these?

That would be my guess as well. I'm just not used to seeing color-bands on through-hole ones.

you mean see through or through hole?

[Blargh523]

Re: Component Identification? What are these?

you mean see through or through hole?

Through-hole as opposed to surface-mount (SMT).

[Phaihn]

Re: Component Identification? What are these?

Through-hole as opposed to surface-mount (SMT).

ok

[eccerr0r]

Re: Component Identification? What are these?

They really do not look like diodes through the glass, but then again who knows... usually there's a visible whisker or orange like the one Blargh posted.

The fact that they're open both ways is bothersome, unless all four of them were fried at the same time... Very weird. A zener diode works like a regular diode when forward biased.

The internal construction of these things look like resistors more than semiconductors which bothers me... but then again they may be fried...

[Evil Lurker]

Re: Component Identification? What are these?

I have seen those before on CRT monitors/tvs on the small driver board that physically connects to the tube pins. Also I have seen similar looking devices on the mains input on some circuit boards. I have no clue what they are either... the only hint is the board is marked "SGXXX" wherein the x's are like any other component numbers.

[Longbow]

Re: Component Identification? What are these?

I believe these may be transient voltage suppressors, known as TVS diodes. These parts will test open until the rated voltage is exceeded. They come in either mono-directional or bi-directional types. The new ones I have are all in the standard black diode package however.

[retiredcaps]

Re: Component Identification? What are these?

SG is spark gap.

http://img.diytrade.com/cdimg/605332..._Spark_Gap.jpg

http://en.wikipedia.org/wiki/Spark_gap

[tom66]

Re: Component Identification? What are these?

Definitely minature spark gaps.

[ben7]

Re: Component Identification? What are these?

Definitely minature spark gaps.

Yeah, the definitely are.

I have some too. They work like neon lamps, they glow orange at about 80v. They look like the OP's too.