Diode - Marking code . Need help.

[ted3023]

Hi all,

I am looking for to identify a through-hole diode with marking code 2 18 (printed in two rows: frist row 2, second row 18). It is a glass case diode. Can anyone help to find its datasheet and its specification?

I appreciate your help.

Thanks.

 

[Skogsgurra]

Many times it is impossible to find the exact replacement. If you don't get the help you need, then consider using a standard diode.

You may have an idea about the specs for this diode. Is it a switching diode, a zener, a shottky, germanium, perhaps? or just a plain rectifying device? Voltages? Currents? Most standard diodes do the job today.

I once had a problem finding an old (German "hand-made") diode replacement and finally got one from an antique piece of equipment. Out of pure curiosity, I cheched data like forward drop, leakage current, capacitance and such things. Found that good old 1N4148 did the job a lot better. Should have tried that firsthand.

Gunnar Englund

http://www.gke.org

 

[ted3023]

skogsgurra,

Thanks for your input. I also think about using any compatible diode, but I have no specificaton about it (diode with marking code 2 18). I am not sure it is whether zener or regular diode. However, it was used in a switching mode circuit and was connected across a MOSFET, and it was a part of pwr supply for lightsource equipment.

 

[itsmoked]

Can you provide a sketch of that part of the circuit? We could probably tell what diode we would design-in for it.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ScottyUK]

Based on what we know up to now, there is a fair chance that it is a fast or ultrafast diode, and probably fairly high voltage. Can you identify the package style? These usually denoted DO-** where the ** is a couple of numbers. This will give some indication of the current rating.


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I don't suffer from insanity. I enjoy it...

 

[ted3023]

Keith,

The unit is at my work, and I have neither a schematic nor a drawing for that part of circuit. I can trace the circuit and make up a partial schematic, but it will take me some time.


ScottyUK,

I found it defective becasue the forward diode direction was opened, and I am looking for its replacement, but have no idea what kind of diode it is.

It is an axial package type, but not sure what type of DO** is it (DO-41, or DO-35, not sure)? It is very small in diameter and a glass case type with orange color. It was marking with two lines: 2 and 18. I also saw some diodes marking like that but different numbers such as 2 and 14, 2 and 16, and 2 and 24. Just want to know who made it and what these numbers stand for.

Thank y'all.

 

[itsmoked]

Directly across a FET.... On a lighting power supply...

What kind of lighting supply?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ted3023]

itsmoked,

It is a lightsource eqipment, which provides light though an optical cable to a microscope or to a camera in surgical equpipment.

 

[itsmoked]

Sorry I wasn't clear in my question.. The "type" of light source was what I was after because it might give a hint to what-all the diode is doing.

Your application smacks of incandescent if 8 years or older. Halogen if 8 to 1 years old and possibly LED if 1 or less years.

If it is either incandescent or halogen then it probably isn't a zener. Just a regular or fast diode for handling the tungsten inductance.

At this point I concur with skogsgurra. Put in a 1N4148.



Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com