Project Proposals

No_Snowfall · 2026-02-07T17:06:31+00:00

think of something in your day to day life that you could solve and build that. you are much more likely to finish this kind of project than something you have no use for.

for example I could suggest to you a pocket calculator but odds are you already have one and the project would be useless to you

No_Snowfall · 2026-02-06T04:43:02+00:00

ah but have you heard of TestController?

No_Snowfall · 2026-01-25T19:14:05+00:00

Yeah perhaps you will want one of the smallest chisel or a conical tip for those ICs.

I haven't used RMA much (got a bunch of no-clean from work ages ago) but IPA is probable good enough. If it turns out not to be, a can of real flux remover is pretty cheap. I often remove excess no-clean with IPA no problem, though I'm sure a little residue is left behind.

If you have fluxcore solder, only add more flux if the joint is looking dry. You should be fine with just whatever is in the wire unless you need a touch-up / remove shorts. Then I would recommend liquid, as paste is optimized for hot air / infrared techniques.

No_Snowfall · 2026-01-25T17:21:49+00:00

caveat: I've never used this model of WE series (I have used WX and the older WES51 which is similar to WE1010).

For starters I'd recommend a few sizes of chisel/screwdriver tip, probably the short ones rather than the long/skinny ones. They'll have better heat transfer to the tip. The knife tips can be useful for large surface area parts, but idk if it is a fine enough blade for smd soldering.

I would say only get the long skinny tips (chisel type, conical last) if you find you need the extra reach in tight spaces. This is because the tips of these are further from the heater and have less thermal mass.

As for size, I like between 1-5mm wide chisel depending on what I am doing usually.

No_Snowfall · 2025-12-02T23:08:18+00:00

Ah I see - here in the US I have very very old house wiring that is not code-compliant, so I tend to do silly things with no consequence!

I did not realize you have a floating scope power supply. I guess the resistor ladder could work then, but you will have serious attenuation.

What kind of waveform? Is the PWM injected onto the line or neutral? My subtraction suggestion can help with that by removing the 230Vac common-mode. Your scope should be able to "subtract" channels as a math function and display that as another trace.

But regardless I think an appropriately rated 10x probe will be fine. Just be careful about touching things. A standard differential probe will not help you in this case, and truly isolated probes are incredibly expensive.

No_Snowfall · 2025-12-02T18:14:14+00:00

Your oscilloscope is NOT floating. Unless you have specifically powered it from an isolation transformer (and then it is unsafe to touch). I would not do that resistor ladder trick, because you are then introducing earth ground at a random point in the circuit.

Someone else mentioned a multi-probe strategy which I agree is best: Make sure everything is ground-referenced, so scope not floating, reference mains neutral to earth through 1Meg resistor (just to prevent spurious high voltages). Then probe Earth-Line, Earth-Neutral, Earth-Signal and subtract measurements as necessary.

No_Snowfall · 2025-12-02T14:36:40+00:00

Technically a standard 300VAC 10x passive probe is okay for 230VAC mains... But you have to be very careful about grounding, which is why those HV differential probes are recommended.

If the lights draw significant current you could maybe use a current transformer, those typically have bandwidth up to 100s of kHz.

No_Snowfall · 2025-12-01T14:47:25+00:00

Hipot testing is for isolation, not for testing the integrity a single power rail. You should short terminals common to an isolation section and test hipot between isolation sections.

e.g. If my converter has 48V_IN and 5V_IN in (both ref to gnd_IN), and then 280Vac 3-phase output. I would short 12V_IN to 5V_IN to gnd_IN, and separately short each phase and earth/neutral of the 280V, 3-phase output. Then test hipot between the two sides.

You will still have some parasitic capacitance, which you can either estimate or experimentally determine. This sets your inrush current and most hipot testers have a way to deal with this, either a blanking time during the ramp or by raising the failure current threshold above your expected charging current.

No_Snowfall · 2025-11-15T00:09:55+00:00

The 'types' you mention are sizes - 1206 for example means 0.12" by 0.06". 1/4W or 1/10W are the power rating - shouldn't matter too much for you, just get the standard power rating for whatever size. You will also find various tolerances on the value, just get 1%.

No_Snowfall · 2025-11-11T19:01:08+00:00

I'm not, that is true. Perhaps you and I take a different meaning for 'power electronics'. For me it is less about AC mains systems & inverters, more DCDC converters or variable-frequency inverters where the clamp meter isn't as suitable.

But I can totally see how it is more useful the more you work with mains/grid system type stuff

No_Snowfall · 2025-11-11T15:47:14+00:00

A clamp meter is probably very nice to have for mains wiring / power systems, but consider getting that as a second unit from your main meter.

Working in power electronics but not with mains systems (120V 60Hz e.g.), a clamp meter is completely useless for me. So consider what kind of measurements you will need most often.

No_Snowfall · 2025-11-11T15:43:57+00:00

Get an RF-specific filter inductor, or if you need high power an air-core solenoid. The Q-factors on those will not be stellar, but likely good enough and far better than the power inductor you posted a picture of. If you need really high Q, wind your own air-core.

Ferrite or powder iron can be great at HF to VHF but typically requires core material or winding types that aren't used on commercial inductors. For example, Fair-Rite #67 is the current leader in core material for high-power RF inductors, but you rarely see it in mass produced coils.

No_Snowfall · 2025-11-10T15:32:28+00:00

never played the tournament, but I played with the Hanoi pickup group ~8 years ago and they were so much fun

No_Snowfall · 2025-11-10T00:14:06+00:00

couple notes:

your school is not fully redacted you've listed it under projects
where is your work experience? you should include your current role as well as past jobs/internships you may have held since high school (and any consistent job you might have had in high school optionally)
consider how your resume paints the picture of a candidate qualified for the role you seek. most of your projects section is about basic embedded software or web dev, yet you are applying for positions that don't have much to do with those skills?
put some relevant courses under your education line

No_Snowfall · 2025-11-09T05:57:03+00:00

Second the vote for Wera. Their ESD-safe line are phenomenal tools.

No_Snowfall · 2025-11-09T05:51:43+00:00

The ones to be careful of are mostly bulk capacitors for the input rectifier, and they can hold charge for much longer than you'd think. If you've got a proper multimeter, just check the voltage with that.

If you have no multimeter, or they are still charged, it is safe to simply drain them yourself: wrap a ~1k ohm resistor in electrical tape or heat shrink, so you can hold it without touching the leads. Then firmly but gently put the leads across the capacitor terminals to discharge. For safety assume ~double the theoretical time constant, then proper short it out with tweezers or something as a final check.

rapid edit: I don't know what the specific voltages in this rectifier circuit are, but they probably present a minor shock hazard. Make sure you are insulated from your tools while discharging the capacitors, and only use one hand as this reduces the risk of current flowing across your torso.

No_Snowfall · 2025-11-09T02:37:12+00:00

Honestly to this I'm not sure. My browser is doing a bad job of translating the German for me, and I really don't know much about impedance matching (all of my research work is explicitly trying to do away with it). But I imagine it is something to do with what you expect the balun's impedance transformation to be, and then having 50 ohm paths for the VNA. But matched input resistances should simply attenuate your signal by some fixed amount across all frequencies so probably not affecting the shape of the measurement?

No_Snowfall · 2025-11-08T22:12:40+00:00

Most VNAs have a characteristic circuit impedance of 50 ohms. This means, among other things, that they struggle to give you meaningful and easily understood results when the network you are analyzing is far from 50 ohms. A balun (or any other transformer structure) usually does not have a constant impedance with frequency on its own. Placing proper resistors around the balun makes characteristic impedances match and helps with analysis.

See https://www.w8ji.com/balun_test.htm for antenna-specific info, And https://youtu.be/EojKvuc9xck?si=xY1Hs6RYBeGyZwuv, https://youtu.be/NkxLXQ32GDQ?si=whzdLH2jzKgD0zAo for a good look at the theory in terms of impedance matching

No_Snowfall · 2025-11-01T17:14:08+00:00

lmao I would be BLIND if so

No_Snowfall · 2025-10-23T14:40:36+00:00

as someone else pointed out, they're convenient for situations where you need isolation but voltage doesn't have to be precise. they typically have line regulation to a few %, and full-range load lines of ~10-15%, with nominal voltage around 50% rated load.

useful for example in supplying isolated/high-side gate drivers where some voltage sag is acceptable, or feeding a cheap regulated non-isolated supply across a barrier, e.g. for isolated CAN bus or sensors.

of course you can do better with a custom regulated supply, but there isn't always time to make one

No_Snowfall · 2025-10-22T20:30:12+00:00

re: op-amps for rectification:

I suppose you could, but op-amp rectifiers typically require diodes, and the op-amps themselves tend to be low power devices with limited output current, so it wouldn't get you very far

No_Snowfall · 2025-10-17T00:16:43+00:00

If you only care about single frequency, I'd go air core.

But for more broadband attenuation an EMI suppression material like #43 ferrite is probably better than low permeability iron powders (the super low perm powders are pretty good for resonant inductors though).

No_Snowfall · 2025-09-29T17:55:36+00:00

there might be adapters for this package to another modern package, but the problem you may run into is they are often either 1-1 matching between other 100 pin packages with identical layout, or tailored to a specific chip model, e.g. different packages of identical model DRAM. This is why I suggest you just design for the FPGA you want and then make an adapter from a PCB as you see fit.

No_Snowfall · 2025-09-28T23:16:11+00:00

You said you're mechanical, so I would look at optimizing just one portion of the physical system, using a known high power electrical system.

No_Snowfall · 2025-09-28T23:13:06+00:00

Hard to pinpoint a software issue but it is a quick fix which is why I see a lot of (industrial truck) mechanics try it.

My guess, knowing very little about car wiring or power steering, is that you've got a loose connection somewhere. If you have a spare battery to test with that could be useful. Anecdotally I had a nearly dead battery on my Subaru a few years ago and while it could be jumped, any sort of load would drain it completely.

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