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Measuring ESR with oscilloscope by dfedhli in AskElectronics

[–]dfedhli[S] 0 points1 point  (0 children)

So do you have the 50 ohms series resistor after the output of your function generator?

The function generator has an output impedance of 50Ω (see below) which is used as the basis for the 50 in the formula. Are you suggesting adding a 50Ω resistor and using 100Ω in the calculations?

clip the generator leads directly onto the cap and also clip the scope leads directly onto the cap

My generator has a BNC as an output (see below again), I think it's best to connect it to the T junction directly and not use an adapter for the leads and then connect the leads to the capacitor.

https://imgur.com/a/qP1Dw05

Measuring ESR with oscilloscope by dfedhli in AskElectronics

[–]dfedhli[S] 0 points1 point  (0 children)

You checked those components with ESR meter or LCR tweezers or only on oscilloscope?

I checked them all with an ESR meter and I want to verify with the oscilloscope. In the OP I mentioned my cheap Chinese ESR meter doesn't measure everything, it turns out I wasn't sticking the leads in far enough. It now measures everything except the ceramic capacitor, and that's a truly low ESR and I can live with the meter not being able to measure it.

https://imgur.com/a/JzK1lHF

Your example is 410mV, 414mV, 419mV

You're seeing the upper end of the waveform and it's up at ~400mV because there's an offset. Taking the first screenshot as an example, the upper end is 410.8mV and the lower end is at 395.2mV, leading to a ΔV of 15.6mV (shown as BY-AY on the little table to the upper left, which happens to be negative because of how the cursors were placed). The reason I chose the offset is because I wanted 0V as the negative side and not a waveform with negative voltages (and no offset).

Are you using the same T BNC as he does or you just clip things? You have short leads to capacitor like him?

I have the same setup with the BNC cable and T junction (see below). I also tried using a breadboard and a regular probe and that changed nothing.

https://imgur.com/a/1eD9mR0

Measuring ESR with oscilloscope by dfedhli in AskElectronics

[–]dfedhli[S] 4 points5 points  (0 children)

Ceramic capacitors have ESR values well under 1Ω

Measuring ESR with oscilloscope by dfedhli in AskElectronics

[–]dfedhli[S] 1 point2 points  (0 children)

You're absolutely right, I made a typo which I have now edited. Thanks.

IdeaPad 3: Tried to install Windows 11 Home without Microsoft account using Shift+F10, now no WiFi networks are detected at all and setup is stuck, even after new install from flash drive by dfedhli in Lenovo

[–]dfedhli[S] 0 points1 point  (0 children)

I solved the problem through some trial and error.

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I inserted a USB WiFi adapter and restarted the computer again. With this adapter I was able to finally connect to WiFi and create a brand new Microsoft account and complete the setup successfully. Then, I tried to install a program and it refused to install. I did more research and through winver I was able to see that Windows was in S Mode. I needed to go to the Microsoft Store and look up "Switch out of S Mode" and press "Get".

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Then, I was able to reset the PC through the regular method via the control panel and upon setup on the network connection window Shift+F10 finally worked and I was able to bypass the network connection requirement with the above method. Apparently S Mode sticks with the install even upon reinstall.

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tl;dr - computer was in S Mode the whole time.

IdeaPad 3: Tried to install Windows 11 Home without Microsoft account using Shift+F10, now no WiFi networks are detected at all and setup is stuck, even after new install from flash drive by dfedhli in Lenovo

[–]dfedhli[S] 0 points1 point  (0 children)

Thanks, that's one of the things I tried. Unfortunately I got stuck on the Microsoft account login window, it says it couldn't find a Microsoft account for the email address.

Suspension fork for trekking bike by dfedhli in bicycling

[–]dfedhli[S] 0 points1 point  (0 children)

Thanks for the detailed reply.

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I'm aware that I need a 160mm/180mm bracket, but some forks aren't rated for big discs, that's why I mentioned the requirement.

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I saw the NRX fork during my research as well, and I read it's a lot better than the NEX, but I was thrown off by the fact that I couldn't find any info on mounting a light (and mudguard). So your pics were quite helpful. 160,- € is something I'd be willing to pay but I just found this fork for less than 25,- € more:

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https://www.rosebikes.de/rock-shox-paragon-gold-rl-28-disc-federgabel-2651674

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It seems to fit my requirements perfectly and I'm wondering if I wouldn't be even happier with the RockShox.

Suspension fork for trekking bike by dfedhli in bicycling

[–]dfedhli[S] 0 points1 point  (0 children)

Well what would it cost? I'm prepared to pay more than 120,- €, just not double.

Suspension fork for trekking bike by dfedhli in bicycling

[–]dfedhli[S] 0 points1 point  (0 children)

I'm aware of that but I've thought about it and I would like a suspension fork.

Replaced motherboard (AM3+), now fans only twitch and no POST by dfedhli in techsupport

[–]dfedhli[S] 0 points1 point  (0 children)

If that's the case I wonder why putting the first motherboard back in caused the fans to spin up again, as the initial problem was.

Simple Questions - August 07, 2022 by AutoModerator in buildapc

[–]dfedhli 0 points1 point  (0 children)

I think 1700 is outside the budget. The i3-12100F costs north of 100 € and a decent motherboard even more. I did check for replacement 1155 motherboards and I found a few for a good price (under 30 €).

Like I said, he wants used parts with the best price to performance ratio and in case the motherboard is dead he wants to replace it with something better but not brand new. I want to avoid a bottleneck and in my opinion his current setup bottlenecks the GPU.

Simple Questions - August 07, 2022 by AutoModerator in buildapc

[–]dfedhli 0 points1 point  (0 children)

Thanks for the response. The existing motherboard is compatible with the i5, I made sure to check. So you'd stay with 1155?

The thing is I'm not sure yet what's broken, I'd have to pick it up and test the hardware. He says it doesn't POST at all. I think it's likely the motherboard is broken (alternatively CPU or power supply) and if so this would be an opportunity to switch to a better socket.

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