Questions tagged [markings]

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.

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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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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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What is this "/|\" symbol on the enclosures of various appliances?

I keep seeing this symbol on old electronics appliances of varying types. Two examples that I own... Early 1960's portable "Megger" insulation tester July 1969 Marconi attenuator I have also seen this on other equipment manufactured as late as the…
Wossname
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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
15
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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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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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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 NOT…
Rev
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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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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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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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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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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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Whose company logo is this?

I can't find any specifications for the chip below, but I believe it is an op-amp good for at least the audio frequency range. It's just marked "A 56" (and maybe shows "a dolphin jumping out of the water"?). This is used on the latest liteVNA…
bobuhito
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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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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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