Used when asking questions about the meaning or use of marks, symbols or codes used on components, PCBs, or cases with regard to controls or connections. Can be used for advice to help identify marking meanings or what markings to use to help others identify.
Questions tagged [markings]
106 questions
66
votes
4 answers
What do the PCB markings mean?
On a printed circuit board, I see lots of tiny letters and numbers. Is there some kind of standard that dictates what letter indicates what type of component?
kinokijuf
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4 answers
Ceramic capacitors: how to read 2-digit markings?
Related question: Ceramic capacitors: how to read 3-digit markings?
I have some ceramic capacitors with a 2-digit marking. How to read them? Do the colored markings at the top mean anything?
Image description:
Brown ceramic capacitors with 10…
Denilson Sá Maia
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15
votes
2 answers
Unknown SMD Component
I'm trying to find the components of the PCB I have. I have a problem with a 5 pin (SOT23-5) component. Can someone help me with this?
There are version1, version2 and version3 of the PCB and marking codes are AA43, AA44 and AACB respectively.
There…
harmonica
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15
votes
1 answer
What does the e3 or e4 printed on an IC mean?
So after staring at a few ICs today, I was wondering what the "e3" or "e4" stands for on the top of an IC. For example, here is an e3:
user1307
14
votes
1 answer
What is a good methodology to identify small SMD components?
Having been in the position of trying to identify a strip of mystery 0603 components I found on my floor, I thought a good general question to pose to this community might be what a recommended set of steps could be to identify similar unknown…
DanSut
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13
votes
3 answers
What do capacitor markings in dash-dot style mean?
I have got a few capacitors in my sortiment which have got dash-dot markings above and below the value code, like this:
What do these dash-dot codes mean? Do they reflect voltage rating or temperature dependency, or do they just denote a production…
aschipfl
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13
votes
3 answers
SMD LED polarity marking: is the cathode marking standardized?
SMD LEDs normally have some kind of marking like the following image from here indicates:
The site states
The CATHODE lead is always the lead to be identified with ALL LEDs, including surface-mount LEDs.
There are definitely manufactures that do…
Rev
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12
votes
3 answers
PCB Logic Board Reference Designator "E"
I'm looking for some help identifying what the reference designator 'E' on this Logic board is for.
Can these pads be used as test points when trying to find a fault?
The board is from a Datamax O'Neil / Honeywell industrial printer (I-4212e)
Nick
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11
votes
4 answers
Various Small capacitors' markings?
Wikipedia explains the basics about the markings of capacitors, here. It lacks many markings most of which confuses me:
Ceramic brown-yellowish cap
104 K5K (small ) --- what is the end "5K"? (Cannot be 5 kelvin as operating temperature!?)
10 (box…
hhh
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9
votes
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What is ohm joules (ΩJ) unit used for?
I found the following component but I don't know what it is. In particular, what does the ΩJ unit mean?
doubleE
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8
votes
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What do multiple contact ratings on a relay represent?
I have some questions about relays. I'm putting together a board that will use 5 V as the trigger for a SPDT relay. The device I'm connecting to the load side of the relay consumes 24 VAC up to .75 Amps.
I've seen several relays and have some…
LoganRoy
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8
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3 answers
Is this capacitor marking in pF or µF?
Capacitor marking with line underneath; these aren't tantalum (I don't think anyway), so I'm not sure which units the capacitance is written in.
Shashvat Verma
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8
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3 answers
What does the "D/V" marking on small DC motors mean?
I have noticed with the large amount of optical drives and CD/DVD players I have taken apart that most of the spindle motors (RF-300, RF-310, RF-400, etc.) have the somewhat cryptic marking "D/V 5.9" on them along with the standard part number. This…
3871968
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7
votes
3 answers
What is the meaning of speed grade marking on Xilinx FPGAs?
According to Xilinx FPGA product datasheets, the numbers on the 5th line as 4C or 5I stand for speed grade and temperature.I have a XC3S400 with 4C speed grade (4= standard speed, 5= High performance).
I want to know what exactly the standard speed…
Aug
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7
votes
3 answers
What are markings on top of electrolytic capacitors?
I often see a marking like the following pattern on the top of radial PTH elcos.
What does it mean? Is it an identification of the manufacturer?
stevenvh
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