Electronics > Beginners

Identifying SMD components

(1/3) > >>

HyssSnake:
I recently obtained several kilos of random electrical components and whilst some had printed information on the packaging most did not.

I just wanted to ask the best way to identify some of the tiny components that seem to have come on short strips for a pick and place machine. With a torch, a magnifying glass and my tongue at the right angle I can make out some writing but I couldn't tell the difference between a 0, an O or a D, similarly with 1 or I, or 5 and S.

Additionally they seem to just have 3 digit codes with a 1 or 2 digit code vertically printed and i have no idea what they mean.

Thank you for your help.

Michael

Fred27:
For a start, take one of each tape out so you can read it. Are they 0805/0603/0402 pieces? Generally I've found resistor have a 3 (or 4?) digit code, capacitors are unmarked. You may need to give us a bit more to go on though.

Leuams:
If you have any transistors you may have luck decoding them with a SMD code book or search site. A quick google search gave me the following hit:
http://www.marsport.org.uk/smd/mainframe.htm

I haven't had much luck identifying SMD transistors.

KL27x:
Learn to use the diode test on your DMM.

Transistors, you can at least figure out if they ARE trasistors or FETS. And with a scope and a signal generator, you could at least quantify their performance; or with a project, you could find out if they are good enough or not. 3 pin parts can also be diodes. Or voltage regulators. Or voltage detectors. Or.. well, I dunno what else.

Anything with four pins, you should maybe at least test to see if it's an optocoupler or an SSR. Optocouplers because they're common. SSR's because they are unreasonably expensive, for some reason. So even if it's a long shot, at least take a crack to see if it's an SSR.

Anything with 5-6 pins might be an opamp or a comparator. But good luck with that, since there are several pinouts for those types of parts and testing requires more external components. And dozens of other things they could commonly be.

Eight pin IC's I'd at least check for possible FET. They have standard pinout, so easy to test, anyway.

HyssSnake:
Any tips on testing a SOT-23 component with a multimeter, I fear my standard fluke probes are a bit big it keeps escaping when I try to test it. From the sheet Leuams posted it could be a thermistor or a PNP transistor but I can't seem to test well enough to be sure of either.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod