42 votes

Parts shortage, no stock, what now? (canonical reference question)

I work at a major analog IC manufacturer since 1990, and I have seen these kind of supply shortage cycles. These cycles come and they go, like the weather. From an IC manufacturer's perspective, the ...
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  • 13.4k
24 votes
Accepted

Why does my MOSFET always burn?

It looks like you have two problems here. Your steady state losses are excessive; you say there's no heatsink, but 1.5 W (incidentally, your current of 1.5 A will actually result in a power loss of ...
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  • 19.8k
23 votes
Accepted

Which manufacturer's logo is this?

Which manufacturer's logo is this? Nichicon (or fakes): - Here is the actual part (UCM series marked as CM): -
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  • 384k
19 votes

What is ohm joules unit used for?

That's not J for joules. It's probably J for 5% tolerance. The component is just a 10 mΩ resistor with a 5 W rating.
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  • 4,705
18 votes

Parts shortage, no stock, what now? (canonical reference question)

I'm answering as a circuit designer facing the supply challenges of 2021 when trying to use high-specification silicon carbide transistors What do I do? I've been facing supply problems for a design ...
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  • 384k
17 votes

What is ohm joules unit used for?

"J" means a resistor value tolerance of +/- 5% as per this site. The resistor in question has a value of 10 milli-ohms (\$m\Omega\$). It also applies to capacitors as per this wiki site: -
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  • 384k
16 votes

Component Tolerance Probability

The problem is, nobody knows. Each manufacturer may work differently. You might ask a specific manufacturer about a specific series of resistors how they are binned, but why would they reveal that ...
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  • 89.7k
15 votes

Is there any difference between Silicone and RTV

For electronics work you want "platinum cure", "addition-cure" or electronic grade silicone. "RTV" means "room temperature vulcanizing" and is a generic term ...
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14 votes
Accepted

What does this beautiful 8-winding magnetics do?

This could be part of an electron beam stigmator. A solenoid with an axial magnetic field can focus/defocus an electron beam. If you have 2nd order and higher astigmatism to correct, you need higher ...
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  • 11k
14 votes
Accepted

What is this blue capacitor?

It is not a capacitor, it's an inductor, and it's not leaking, it is held firmly in place with glue.
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  • 89.7k
13 votes
Accepted

What does this schematic symbol mean? (Circle with an arrow in it)

That is a current source. It will be a sub-circuit to generate a reasonably constant current through the push-pull output transistor biasing circuit. To avoid cross-over distortion (a discontinuity on ...
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  • 160k
13 votes

In terms of costs of mass production: is it better to try to reduce resistances' tolerance or capacitors' tolerance?

Generally it is much cheaper to get tight tolerance resistors than capacitors. You might find that even 5% resistors are mostly within 1% since the manufacturing process for resistors has become very ...
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  • 19.7k
12 votes

Why does my MOSFET always burn?

Do you have any cooling or heatsink on the MOSFET? The on resistance of the MOSFET will cause it to dissipate ~500-600mW of heat. The MOSFET has a thermal resistance of junction to ambient of about ...
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  • 26.2k
11 votes

Parts shortage, no stock, what now? (canonical reference question)

I had worked for 40 yrs on all sides of component choices as a designer to Ops Mgr of SMT R&D responsible for all aspects of purchasing, stock picks, and order management to eng mgr for a major ...
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11 votes

Which manufacturer's logo is this?

They are nichicon capacitors, here is a pic of a similar capacitor Source: https://in.element14.com/nichicon/uwd1h221mcl1gs/aluminum-electrolytic-capacitor/dp/1899629 Source: https://www.farnell.com/...
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  • 63.7k
11 votes

Is this component a resistor or an inductor?

It looks and sounds like a fusible resistor. I say this for two reasons (1), it measures an open circuit (it has fused hence the reason you are investigating it) and (2), fusible resistors quite often ...
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  • 384k
10 votes

What are these two rectangular, black components?

SMD tantalum capacitors The "J" means 6.3 V. I don't know what the value is, but, from the size, I'd say around 30 to 100 uF.
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9 votes

Parts shortage, no stock, what now? (canonical reference question)

Just spent last 2 weeks scrambling to secure 2 years' supply for what should be very ordinary BOM's that were 100% stock until now, but came in with 52+ week estimates for some parts. Part of the ...
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  • 1,157
9 votes

Parts shortage, no stock, what now? (canonical reference question)

As a hobbyist/student, you are stuck with the stock that common suppliers have. You can buy demo or hobby boards and remove parts if you're hard up. As a company, it is very important to have a face-...
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  • 4,058
9 votes
Accepted

Component Tolerance Probability

In ancient times, with carbon composition resistors, there was generally a reasonable spread of values - for "precision" circuits you might get instructions like "pick through your 100 ...
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9 votes
Accepted

What kind of component is this resistor-like part?

It's a 10,000 pF (0.01uF) axial-lead ceramic capacitor. It should measure open circuit on a resistance range of a multimeter and close to 10nF on a capacitance range. Replacing it with a radial leaded ...
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8 votes
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How does this glass-protected surge absorber work?

It is a precision microgapped conductor <<1 Ohm in an inert gas that goes thru the normal fast pre-glow ionization microsecond period then arcs much faster as an avalanche feature like all gas ...
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8 votes

Help Identifying SMD components + How is one meant to know what these are?

Firstly, are a number of these small surface mount boxes which are a light grey color. I have tried a number of multimeter tests on them. They do provide 0.5nF capacitance, so does that mean its a ...
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8 votes
Accepted

What is this strange black rubbery component? A capacitor?

It's an unshielded (drum type) inductor with shrink-wrap tubing around it to protect the winding. Hence the designator "L2". Part of a switching regulator. Edit: The PN8016 switching ...
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8 votes
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Is there any difference between Silicone and RTV

Cheap silicone is acidic (like vinegar) while GE's Room Temperature Vulcanizing (RTV) is not, and is suitable for electronic anti-corrosive insulation on metals. The main features are thermal ...
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7 votes

What is this mains blade connector called?

That is a NEMA 1-15P. The connections internal to that device are probably custom -- connectors are something that are easy enough to make that for volume manufacture you'll often see partial or full ...
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  • 36.3k
7 votes

What does this beautiful 8-winding magnetics do?

To add to the previous good answer some intuition as follows with optics and waveform required. In optics we have corrective lens that depend on the spherical and cylindrical correction opposite to ...
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7 votes
Accepted

Help identify IC

Found it, and deleted my previous answer. How ironic was finding the IC after saying "almost impossible to find" (facepalm). Anyway, here it is: AOZ1282 What we did wrong was to Google "...
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7 votes

Why is the Base-emitter ON voltage as high as 2V in the BJT datasheet?

The 0.7V is a typical rough estimate value for a typical generic small signal transistor with few milliamps of base current. It can be used as a simple mental model in general. What you have is not a ...
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  • 89.7k
7 votes

Why is the Base-emitter ON voltage as high as 2V in the BJT datasheet?

Your BJT datasheet plots always shows nominal and the tables show Max. I added what to expect in Red to interpolate for worst case MAX devices due to process variances @ 25'C These are exceptionally ...
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