askelectronics

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bekopharm, in What software do you use for PCB design?
@bekopharm@discuss.tchncs.de avatar

KiCAD is good and has no vendor lock-in.

There are very good beginner tutorials and videos explaining typical workflows.

It features also stuff like auto-routing, error checking, part lists and 3D previews.

M_Reimer, in What software do you use for PCB design?

I would recomment to try Kicad for this. It is free and should do just what you want.

thzihdd,

Second that. Did my own Keyboard design with it with zero preknowledge and available community resources.

MrPozor,

Another vote for Kicad. I have done a small project with it and it worked perfectly.

Saigonauticon,

Yeah! I tried it years back, and it was not so good.

Fast forward to this month. I try it again and am really impressed! It's great now!

I was using it on client work within hours.

opensesame11, in What software do you use for PCB design?

I use Altium Designer and KiCAD. KiCAD isn’t as good by just a hair but makes up for it by being free and open-source. Altium Designer is also crazy expensive for hobbyists.

ottk3, in replacement for male connector
@ottk3@discuss.tchncs.de avatar

That's a 5 Pin JST-XH Male connector.

afunkysongaday,

Thanks for your help! Looks almost identical, but not exactly! The little plastic tabs on the edge are a bit further apart on the connector you send me. Or at least that's what it looks like on pictures I find:

https://beehaw.org/pictrs/image/ab987ff1-7fea-464e-8104-b7881163d733.jpeg

Here the little plastic tabs are roughly above pin 1 and 5, on my connector it's more above pin 2 and 4... Hope you can understand what I mean. Any idea?

ottk3,
@ottk3@discuss.tchncs.de avatar

That's true. Maybe a PHR-5 JST Connector 2mm Pitch instead?

PHR-5 JST Female Connector 2mm Pitch

Source: https://uk.rs-online.com/web/p/wire-housings-plugs/8201472

afunkysongaday,

That seems to be it! Or "JST-PH"? Not sure what the difference is between PH and PHR-5. 2mm pitch seems to be it at least, and plastic tabs seem to be at the right place:

https://beehaw.org/pictrs/image/83a78341-4922-4d13-9722-a55e6b6db785.jpeg

https://beehaw.org/pictrs/image/2c82fdcb-94fb-4659-87b2-937d7e7f179b.jpeg

(Backside of PCB from pictures before)

Just order some of the generic ones I find for " JST-PH" on aliexpress and pray? You are a great help, thank you!

bmiww,

Found these over at Amazon: amzn.eu/d/6HDzJIR

Can’t say for sure if it’s a full match, but as far as generic goes - maybe this is faster than waiting for AliExpress at least.

ottk3, (edited )
@ottk3@discuss.tchncs.de avatar

As far as I know are the “PHR” series connectors a variant of the “PH” connectors. They also have a 2.0 mm pitch, but they differ slightly in their housing design. The primary difference in the “PHR” connectors is the presence of a latching feature on the housing. This latch helps to secure the connector halves together, providing additional stability and preventing accidental disconnections.

Check out this page: Common JST Connector Types – Matt’s Tech Pages

farnell.com | PHR-5 Technisches Datenblatt

afunkysongaday,

I ordered some of these:

https://beehaw.org/pictrs/image/f2232dfa-a7dc-4c7c-a09c-7ebf1f9e475e.webp

With a little bit of luck it should be an easy repair. Thanks again!

HakFoo, in What software do you use for PCB design?

Another tool worth exploring is EasyEDA. The fun part is you can even run it as a webapp.

It's tightly linked with the JLCPCB/LCSC ecosystem, so there's a lot of libraries of parts and it scans for their design rules, if you want to use their services.

There's also a somewhat basic auto-router baked in, which is harder to integrate in KiCAD.

I do agree that KiCAD is the consensus "full fat" tool these days, but I've put together decent projects in both.

ron33, (edited ) 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.

dfitz, in Location of BIOS/CMOS security chip on Thinkpad T470?

IFixIt have a guide for removing the CMOS battery if that helps at all.

pneumapunk, in SBC UART debug troubleshooting

In addition to the voltages being different between real-RS232 and "TTL"-serial, they're also swapped. On a DB9 you probably have something approximating RS232, where mark=-9V and space=+9V, but the debug header is likely mark=+3V and space=0V. So even if your inputs can handle a wide voltage range, the sense is inverted, which is why you'll get garble.

(For example, when the line is idle it's at the 'mark' voltage and the receiver knows a character is incoming when it transitions to 'space' for one period (the start-bit). If mark and space are swapped, the receiver will see 'space' most of the time and only detect a character starting when there are some 'mark' bits in the middle of a transmitted character. It'll never actually synchronize correctly with the transmitter.)

You can figure out what you've got with a multimeter and checking what the voltage is on the TX pin when it's idle.

HewlettHackard, in Is the efficiency of a DC DC converter Load independent?

It’s similar to AC-DC. From a simplistic perspective, efficiency at idle will be 0% because the converter itself still uses some power, then efficiency increases with load since the converter overhead becomes less significant as the useful work increases. Googling “dc dc converter efficiency curve” gives plenty of results.

ConductiveInsulation,

So I guess I have to contact Meanwell and ask why the linked Datasheet is not showing that curve. Thanks for the answer.

pneumapunk,

They might be willing to spec it as "quiescent current" (current drawn at 0 load) even if they don't provide a full curve. Annoying that it's not on the datasheet.

lemann, 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, 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, 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

teri, in Help Bypassing Timer on LED Lights

https://discuss.tchncs.de/pictrs/image/3820e804-d4cd-40d9-8d0f-18788d0ee9af.png

Difficult to find datasheets…

Second picture: To me looks like Q1 (3400) is an NMOS which connects the LEDs to power. The ‘gate’ is marked yellow. It is the ‘control’ input of the MOSFET. The 4 resistors RD RC RB RA (purple) probably limit the current through the LEDs. If you’re lucky, then an easy hack would be to bypass this transistor: Remove Q1 and connect the red and green marks via a mechanical switch. You’d need to scratch away the white coating until you get copper. Then solder wires there. As a consistency check you could measure the voltage over Q1 (red and green marks). Measure once when the module is plugged in but switched off, and once when the LEDs light up. If you see a voltage while the LEDs are dark, then this would partially confirm my guess. As a test: Before removing Q1 you could also try to bypass Q1 with a resistor (~ one, two kOhm) while the LEDs are off. If you see LEDs now lighting dimm, you know that Q1 is the one switching the LEDs.

Other possibility: It might possible that the timeout is computed with an R-C circuit. for 30min you need a rather large resistor because there can’t be very big transistors. R1 (blue) is the largest one. Experiment could be to remove it and see if timeout is still 30min. Or put another 10k resistor in series and see if the timeout gets shorter.

Wondering: What voltage do you connect to the module? Please be extra careful if you have somewhere mains supply voltage.

ProfessorGumby, in Can I get a North American plug for this 36W DC charger?
@ProfessorGumby@midwest.social avatar

something like this should work for you: www.ebay.com/itm/234784865100

Your charger can take 110 v input so you won’t need a voltage converter. Just an adapter should work.

kaladininskyrim,

Thank you

Susan_B_Good, in Can I get a North American plug for this 36W DC charger?

If you mean a replacement slide-in US standard module - I fear that your chances are slim. I don’t know of a standard that applies to such plates. As it came with a, presumably, external disc drive - asking that manufacturer or its US agent/distributor for help might get something. Even a free replacement power supply. Worth asking, surely?

I don’t recommend using an inline adapter - unless used vertically, the leverage would be too great, unless you added a third leg… You might look for a right angle adapter - that’s the norm in the UK. They can work out well.

Otherwise, you could get an EU socket strip, replacing the plug on the end of its cable with a US one (if it doesn’t actually come with a US plug already).

kaladininskyrim,

Yep, I meant a replacement slide in and was hoping there was a standard for these things. Makes sense to get a power strip. Thanks for the response!

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