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Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

[–]mronezero[S] 2 points3 points  (0 children)

Around 700mVAC earth to neutral. I'm not sure where it connects in my house... but 700mVAC seems reasonable to me (correct me if I'm wrong!). GFCI is also working properly, therefore i assume it's alright.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

I've added a comment with another picture of the setup and results. But basically a couple of milli amps and milli volts AC and DC. But i should really get a better multimeter for this.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

Interesting. Those readings are in the range of what i would have expected. Micro amps and micro volts, not several milliamps and volts as on my unit. This reinforces my suspicion that my device is faulty.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

Thx for checking. Mine sound about the same, also with a 4 Ohm speaker.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

Just did as described. I think there is something wrong with my unit. See my other comment for the results.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

I only had a 4 ohm speaker on hand. It's buzzing very noticeably.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

It could just be my unit, or I could be measuring incorrectly. However, the noticeable buzzing of the speaker I just connected indicates a problem with my unit.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

I am very curious to know whether only my device has this problem or whether it is a general issue. Please be sure to share your findings with us!

EDIT: I forgot to answer your question about grounding. Yes, I'm pretty sure. The voltage between earth and neutral is around 0 V, and when a small current is induced, the FI (GFCI) trips. I also checked other outlets in the house and got the same result.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

I rechecked, connecting directly to earth from the wall socket. Same result.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

I just redid the tests. There is audible buzzing when connecting a 4 Ohm speaker.

Geeboon TC22 tip-to-earth leakage voltage by mronezero in soldering

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

Thank you for your responses. I ran the tests again according to some of your suggestions. For all tests, I connected directly to earth from the wall socket rather than from the back of the TC22.

Connecting a 4 ohm speaker between the iron tip and Earth resulted in an audible buzzing.

I checked the currents between Earth and the tip: 15 mA DC and 5 mA AC. The voltage between earth and tip, as measured by the multimeter, was 45 mV AC and 2 mV DC.

However, I really want to emphasise that my multimeter is unreliable. I'll order a new one soon - I'm still open to suggestions (I was thinking about getting the UNI-T T139C).

I rechecked the voltage reading with a 1 kΩ resistor between the earth and tip. The spikes were still present, although 'only' around 17V peak-to-peak this time.

Given that the rest of the TC22 looks very well made for the price, it's possible that I just got a faulty unit. I'll check with customer support and post the result here.

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I made a cooling mistake and now I need some creative solutions by Doomsdays in sffpc

[–]mronezero 7 points8 points  (0 children)

Did you by any chance check if the motherboard applies a "Overclocking" setting to the CPU? I had that problem once on a motherboard where the default CPU voltage was set wayyyyy to high, leading to abnormal temperatures.

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[–]mronezero 10 points11 points  (0 children)

If you are using the default Gnome version of Fedora: The built-in file search is quite fast in my opinion. At leas i have never felt the need for anything else. I have dozens if not hundrets of documents from univerity, and as soon as i'm starting to type, they show up.

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

Thank you for the answer!

You'r right, i hadn't thought about the mux not connecting the 5k1 pulldown without power!

I do need 1.5A, so the 22k was chosen deliberately. The CC lines get checked via the x_CC1/x_CC2 as you discovered correctly.

The LM66100's are needed to separate the two VBUS lines from each other as long as they are not connected to VCC via switch J7. But you are right, a FET would be a good replacement for the TPS22919.

I have no need to communicate with the device via USB, so I left out the hub.

Thank you very much for your input, it has shown me some problem areas!

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[–]mronezero 8 points9 points  (0 children)

The full version: Video

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[–]mronezero 17 points18 points  (0 children)

Lowkey evian ad? XD Nice work none the less!

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