discuss.tchncs.de

grasib, to askelectronics in Non-Inverting LM358 Circuit Not Working

the first thing i'd do is connect the GND from your arduino and from your power supply. At the moment there does not seem to be a common ground or it is off picture.

Drich98,

The circuit works when there is a common ground (makes sense ofc but originally I thought they had to be separate), I didn’t want to put 5V and 12V on the same rail of the breadboard. Now what I find strange is that even without the 5V input voltage, I still get 10V at the output of the Op-amp which is very confusing.

Double_A, to askelectronics in Is this one-piece battery-to-PCB "clip" standard (for easy replacement) or a custom piece? +PCB pad ?
@Double_A@discuss.tchncs.de avatar

It doesn’t seem horribly corroded. I would just sand it down to bare metal and just use it like that.

blarbasaurus, to askelectronics in Did I damage my crystal?
@blarbasaurus@lemmy.world avatar

Assuming that this is a 10MHz reference, at the extreme your reference is 0.003Hz off from nominal (3e-10, or 0.3ppb error). It varies by 0.08ppb in the plot. IDK what it is that you bought (TCXO, OCXO, whatever), but that's rather impressive stability. Depending on what type of oscillator it is you can expect a temperature coefficient anywhere in the several ppm to 0.1ppb. Do you know by how much the ambient temperature (or even better, the oscillator temperature) changed over the duration of the plot? I don't work with temperature-compensated oscillators very often, but I don't see an issue here.

sweafa,

i assume its measured under laboratory conditions, so it seems ok to me. TCXO, OCXO should usually be operated within their operating voltage range. depends on type. usually i would assume 1.8-3.3v, but who knows without datasheet?

drwho, to askelectronics in This variable cap, sending a clear message to anyone looking for identifying marks

It's probably between 60 and 140 pF. Those are the ones that you'll normally find in crystal radios for tuning.

ron33, (edited ) to askelectronics in Is this one-piece battery-to-PCB "clip" standard (for easy replacement) or a custom piece? +PCB pad ?

Thanks so much for the comments.

After viewing in-stock battery clips, did get the impression it was custom.

Interesting suggestions re: part from a broken one, foil /paperclip, and shape-your-own (not set up to re-plate).

Since it’s summer here, do have a while to explore options before the next heating season.

PS For future reference, does this sort of exposed PCB trace (pad?) used for electrical connection take solder well?

https://discuss.tchncs.de/pictrs/image/0579ac1a-57af-45fc-a6a6-48d27754ac5b.jpeg

Enclose0314,

PS For future reference, does this sort of exposed PCB trace (pad?) used for electrical connection take solder well?

I can’t tell if you have gold plate or just raw copper (probably gold. But in either case, yes, it is solderable. You can think a little bit about how they manufacture the boards. First the print on the green solder resist, then they dunk it into an electroplating bath for a gold finish, or a dunk it in solder for HASL. It would be a lot of trouble to go through (=$$$) to individually mask off that part of the board for some special process.

lemann, to askelectronics in Is this one-piece battery-to-PCB "clip" standard (for easy replacement) or a custom piece? +PCB pad ?

I'd assume that since it's from a thermostat, it's likely a custom made part - most of the common traditional thermostat companies like have been around for a while tend to mostly reuse their existing custom designs instead of using standardised components

Since it's peeling this could be difficult to salvage too... usually I use foil to solve connection issues caused by corrosion, or have a poke around on Ebay for a secondhand one if it's really bad

You could also consider re-shaping a (conductive) paperclip to contact the aa battery in a similar way.

pneumapunk,

I've had middling-to-good results making battery contacts out of springy bronze metal stock. It solders well, it's easy to shape, and if you get the right kind of metal it retains its springiness well. (510 or 544 alloy, maybe? It's been a while.)

Susan_B_Good, to askelectronics in Is this one-piece battery-to-PCB "clip" standard (for easy replacement) or a custom piece? +PCB pad ?

Acid etch, followed by electrolytic copper plate, followed by nickel plate.
Sorry, can’t help with sourcing a replacement.

sweafa, to askelectronics in can someone please help me find this IC charger pump?

How many pins does it have? I can’t see it properly in the image. Is it 4, 8 or 12 pins?

sunkryst,

i just checked with the person who checked my computer, 12 pins

sweafa,

unfortunately i neither could find anything. richtek has some weird packages like this:

https://discuss.tchncs.de/pictrs/image/449d3b62-5d64-4ab9-9f3d-03f1d287523e.png

or like this:

https://discuss.tchncs.de/pictrs/image/01dc314f-7a2d-4f9f-a7cb-060fd39a9ae6.png

so i poked around their homepage. but could not find anything with that pinning. also FMM marking is not in their marking reference :(

sunkryst,

thank you so much anyways 🙏 i’m still looking for the schematic

sweafa,

diodes uses packages like this one: www.diodes.com/assets/…/V-QFN2030-12-Type-HE.pdf but cant find FMM marking there …

sweafa,

it could be worth a try to contact diodes and ask which components use or have used in the past V-QFN2030-12 (Type HE) package

sunkryst,

thank you so much for your help!! i will contact them. my searching for the gateway schematic gave no results :( even in chinese google…

sweafa,

looks very similar to that: www.ti.com/product/TPS566235

crm, to askelectronics in Help finding replacement charging jack

They are available on ebay, for example: https://www.ebay.com/itm/362503636436

OddFrog,

THAT’S IT thank you!

feidry, to askelectronics in Help finding replacement charging jack

As the other commentor said, ebay is a good place to look for such things but don’t search the part numbers. Search the model number of your device. Get the model number as specific as possible. Sometimes there’ll be a model number printed on the outside or on the box it came in, and that number is like a customer facing model number with a different model number that the manufacturer goes by. Like you’ll have a Samsung Note 8 and that sounds like the model, right? But in reality, it’s a SM-428Z-J12 or something. That’s the model number you want to search. Do some research on your device to get the right one.

OddFrog,

Thank you for the advice! Was starting to lose my mind scrolling pages of parts.

OddFrog, to askelectronics in Help finding replacement charging jack

Searching for the number hasn't gotten me anywhere neither has searching by the dimensions of the jack. Would like to avoid stealing parts off other systems but as a last resort would consider it.

DavideAndrea, to askelectronics in Help identifying jst connector

I already answered your question when you asked it in Stack Exchange.

In summary:

  1. You reported the wrong pitch: that's a 1.5 mm pitch, not 1.25 mm.
  2. That is a JST ZH: https://connectorbook.com/identification.html?m=NN&n=lo_prof_1r_w2b_conn_1p5&s=ZH
ishelly404, to electronics in I got another oscilloscope from a ham fest.

Nice! Hamfests are great for stuff like this.

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