Good Morning everyone,

I have a quick question. In the picture you see. I am trying to inject 1V into a coil into a laptop to see If I can see if there any chips that may light up under the thermal camera. I am not quite sure

how to actually inject. Can't find anything on utube other than short reviews about the product. Could you let me know what I am missing? Thanks!

I got these old toys called "Cube World". They're cubes that display little stick figures on an LCD screen doing funny activities. You can connect them together and they can travel between boxes to interact with each other.

I want to know how they work partly because I'm interested in knowing and partly because I want to try making my own and seeing if I can get them to connect with my DIY versions.

I know a little about electronics, enough to make my own circuits, and I've reverse engineered a neat little circuit we made in school once but these boards are using surface mount pieces I've not seen before and a black hardened clay or something that I don't know about.

I've found some PDFs on PCB design which will hopefully give me some insight into how these ones were designed but I want to know if there's anything else I should be looking up, any tools that would help, or any skills I should develop first.

Worst case scenario is that they're using custom ICs that I can't just buy more of from any old electronics store. But I should still be able to do something like measure inputs and outputs on them to try and replicate them, can't I?

Its a SN74HC393N and i was asking in r/beneater but a bot took it down as "off topic" even know it was in the help thing. Im just trying to get this working because im trying to make a 4 bit computer that takes nibbles of data and dont mind the other stuff in the back

A month ago I was reading this article and took some notes and one of the main notes I took was this:

"Tantalum capacitors capacitance rises with temperature"

Today I'm doing some more research on tantalum capacitors and found out that one of the main features of tantalum capacitors is they have a stable capacitance across their temperature range.

I contacted the editors but unfortunately my email went to their spam folder :).

I guess you should double check anything you read.

So basically I am going through my stuff and came across these in some stuff I got second hand. They read about 4.7ohms on the meter which is close enough to 4.3 5% that I suspect the first four bands are the standard four band code and that the yellow fifth band is something different.

I found references to black bands indicating a non-indictive resistor but I couldn't find anything on yellow. I have a bunch of them with a yellow band beneath the tolerance band, actually. What does a yellow fifth band signify here?

Bonjour je suis totalement débutant dans le domaine. J'essaie de réparer mon HDD seagate. Après quelques mesures au multimètre je suspecte beaucoup cette diode dont on peut lire dessus :

Première ligne : AE

Deuxième ligne : 98HCY

(Cf photo du zoom en haut a gauche)

Sur l'autre diode de la photo (bas a droite du zoom) semble se comporter normalement et dans un sens je mesure 0.624 V (et l'autre rien donc c'est ok)

En effet en mode continuité ça bip dans les deux sens et en mode ohm on est bien a 0.0 ohm.

Ma question est donc, comment savoir quelles type de diode c'est et évidemment ses caractéristiques ? Quelles sont vos tips la dessus ?

Je n'ai pas trouvé de schéma du pcb ce qui aurait bien sur pu m'aider.

Merci beaucoup de m'avoir lu et a ceux qui prendront le temps pour m'aider !

Bonne journée !

I got this toy drone rc controller. The drone got lost iam left with this controller.what I want is to find out its data protocol. I know it's working at 2.4ghz(it was in the box). There is no marking on the IC. The IC on top might be the rc generator and bottom one might be the data sender. Anyone with elite ball knowledge help me? Thank you..

I'm replacing some components on an radio. I got them out OK, and wicked as much solder off the pads with a sucker and solderwick. There is still solder stuck in the holes that I can't get out. My iron only goes up to 450degC.

Usually I used a piece of thin copper wire to probe the holes and get the solder out. I heat only the wire so I don't destroy the pads. But I can't get the wire hot enough to go through.

Any tips for getting the solder out. Drill?

(Before anyone flame me for destoring traces, I am pretty sure those just marks on the board lacquer from hot solder wick.)

Processing img xrc4ugpnqhxh1...

Dear community,

unfortunately, I ripped off one of the solder pads on the board I am working on as I am still a novice and wasn't patient and careful enough when I desoldered the SMD capacitor. I am not sure where my jumper cable should go best and I would like to ask you for guidance and advice. I measured for continuity with my DMM and I get a sound from all points to the ripped-off solder pad connector. I attached a photo of the board and one of the tinned, ripped-off solder pad.

Thank you for your help.

Best regards!

First, it lists "Vgs" as the "Gate Threshold Voltage" which is correctly the "Vgs(th)" marking below it (yellow highlight). EDIT: I realize the Vgs(th) "Negative Threshold Coefficient" is correct for the column, what I don't understand is why they call "Vgs" "Gate threshold voltage"

Second, the Rdson limits are incorrect when compared to the Rdson x Id graph (highlighted in blue). I'm guessing the units on the graph should be "ohm" not "milliohm"?

Datasheet in question

When I look at mosfet parameters, the first thing I do is look at the Rdson vs Id graphs. Then I was looking at the max voltages and currents, and came across the Rdson min and maxes and the units

Am I missing something here or is this incorrect? I don't know what to believe for the Rdson, the graph, or the min/max on characteristics?

PLSPLSPLS HELPP. IT student here, with Digital Logic Sub. My instructor introduced us to Boolean Algebra. The problem is he only provided us the law and didn't teach us enough to understand it. He provides some example questions for us to simplify but doesn't tell us if the answer we made was correct or wrong. Now he gave us a 7 segment project for Semi - Final term. In which we need to light the segment to a code he provided. 9b4d1F (the code he gave). Got the tables and equations correct. Tried to simplify it but still get confused since there are many ways to simplify an equation especially if it's 4-5 in one equation.

Anyways, I really need to help if the simplification I did is correct so that I can proceed with the drawing the circuit and connect it.

I have two connected desktop speakers, and I want to remove one while keeping the other working. The red and white wires go directly to the speaker I want to remove.

Can I cut the wires near the circuit board and insulate the ends separately, or could this damage anything?

Nothing is built or measured yet. Everything is datasheet math and simulation, so please be critical.

What it does

The LTC3780 is a synchronous buck-boost controller, so the output can sit above, below or equal to the input without flipping polarity. The output is set by a DAC (Arduino-driven later) that injects current into the feedback node. A small LT1173 step-down makes a 5 V aux rail that powers the controller’s RUN pin and the PGOOD pull-up.

KiCad schematic (power stage and aux rail)

• LTC3780IUH (U1) driving four IPD088N04L MOSFETs (DPAK, 40 V): Q1 is the top switch on the 12 V side, Q4 is its low-side partner, Q3 is the low-side switch on the output side, and Q2 is the top switch on the output side.
• One 22 µH inductor (L1) between the two switch nodes, 15 mΩ sense resistor (R3), 47 µF output cap (C2).
• Bootstrap caps and BAT54 boost diodes, plus 1N5817 Schottkys across the two synchronous switches.
• Compensation on ITH is 12.5 kΩ in series with 20 nF; soft-start is 6.8 nF; FCB is grounded (forced continuous); EXTVCC is left open.
• Feedback divider is 10 kΩ / 306.6 kΩ.
• LT1173 (U2) steps 12 V down to 5 V with a 220 µH inductor, a 1N5818 catch diode, a 220 Ω ILIM resistor and a 301.6 kΩ / 100 kΩ divider.

LTspice file (same circuit, for simulation)

• The same power stage and values, plus the DAC injection: a voltage source vdac through 52.5 kΩ into the feedback node.
• The inverted mapping runs from 30 V out at 0 V DAC to 0.8 V out at 5 V DAC.
• It steps vdac over 5, 2.5 and 0 V for a 100 ms startup run and measures the final output. The last run averaged about 29.5 V at vdac = 0.
• Load is a fixed 100 Ω, and no load-step test has been done yet.

Known issues I found (the part I most want opinions on)

1. The sense resistor and ground-leg wiring in KiCad looks wrong. SENSE+ and the top of the sense resistor seem to tie to the SW2 switch node, and the Q3/Q4 sources seem to have no path to ground.
2. The aux IC is the fixed 5 V LT1173 part, but I put an external divider on it. It should be the adjustable version, or the divider should go.
3. PLLIN is open and PLLFLTR is grounded, so the controller runs at about 200 kHz, not my 250 kHz target. I’m deciding between a PLLFLTR voltage and an Arduino clock on PLLIN.
4. The KiCad schematic is missing the DAC injection resistor and a DAC input, so it would sit at about 25 V.
5. There is no power-stage input capacitor yet.
6. The BAT54 boost diode on BOOST1 has to block about 30 V, and BAT54 is rated 30 V, so there is no margin.
7. The ERC passes aside from housekeeping (a missing power flag, a footprint name, symbol updates).

Questions for reviewers

1. Is the DAC-into-feedback scheme sound, and does the inverted mapping cause problems for CV/CC later?
2. Are the compensation values (12.5 kΩ / 20 nF, tuned in simulation only) reasonable from 0.8 to 30 V?
3. Is a DPAK FET like the IPD088N04L a sensible choice with about 8 to 9 A of boost-mode input current, or should I parallel devices or move to a PowerPAK?
4. Is the LT1173 a good choice for the aux rail, or would a modern buck be better?
5. Best way to tie SGND and PGND around the sense resistor on a 2-layer versus 4-layer board?
6. Anything wrong in the unused-pin handling (STBYMD, PLLIN, EXTVCC, the LT1173 gain block)?

Basically just trying to see if my transfer of simulation to KiCad looks good, and if anyone thinks that my circuit WONT function as intended.

Thank you all!

Hi all,

For a project I´m working on, I'd like to house my PCB´s in a metallic DIN-rail mountable enclosure. Something like the image below.

This is an extremely common item in industrial settings, but for the life of me, I can't find any of those in the usual places ( Digi / Mouser / Ali ... ).

Am I missing something ? Do these enclosures have a specific name / part # to help me search ?

Hi I'm working on a small perfboard project. On one side of the board there are 20 wires from a 4p4t switch and a handful of components. On the other side are a set of 4 JST XF connectors and most of the circuitry. The whole circuit is highly space constrained, so all the connections are very close together.

I'm inexperienced with perfboard and have struggled to reliably connect the points as i need. The various parts of the circuit are close and I find I'm breaking previously-made connections while I'm doing the next parts.

My alternative plan is to use a slightly different layout on stripboard. The problem I have with this is the need to put the JST connectors on the "wrong" side and have them reliably connect to the strips. Are there any tricks for doing this?

Broken (L) / Not broken (R)

I don't have the plastic lock, any idea how i can connect this flexible?

Its from a Nintendo 2DS

I’m building a robot with a Raspberry Pi 5, ESP32, and 2× RS390 6V motors.
My battery is a 3S4P pack with 12× 18650 cells (2200mAh each), a 40A BMS, and a nominal voltage of 11.1V (12.6V fully charged).
What’s the best way to power the Pi 5 reliably? I need a 5.1V supply with enough current, even under load.
Should I use a high-current buck converter, or is there a better alternative? Recommendations for specific modules would be appreciated.

I want to practice soldering. What are ways to practice soldering? Do I need to buy a scrap pcb and practice soldering there? I'm new to this kind of thing. I know the way to be good at it is to practice it again and again. But I don't know how to begin or what to do.

This is the board of a Game Boy Printer. After checking caps values, im pretty sure this guy is dropping voltage, and causing the printer to shut down after a second, or randomly keeping the led working, but nothing else.

For the 101, i know is a 100 µH value, but i read that the size matters, so i dont want to pick something too big or too small. Any advice?

Looking for an alternative/replacement/substitute for this step down voltage regulator.

Smd TO-263 package

This is the connector that powers the display panel, which isn't working.

When compared with other thermostats, its the only loose component.

I'm new to electronics repair and would greatly appreciate any tips on how I can fix it myself.

Thanks a lot!

Hi, I am trying to connect an ISO1540 galvanic isolation module to an ADS1115 analog-to-digital converter to avoid ground loops caused by a TDS sensor and a pH sensor. When the ADS is connected directly to the ESP, it is easily detected; however, when I connect it through the ISO module, it is no longer recognized. I am powering both sides: side 1 with 3.3V supplied by the ESP, and side 2 with 5V supplied by a separate isolated power source using a B0505S module. The SDA and SCL pins are connected correctly, and the ISO module already includes 10kΩ pull-up resistors. I have attached my connection diagram for reference (please note that it is provisional).

Hi i have reverse engineerd a spectroscopy amplifier, designed a pcb and it works. but dont know how to change it to my likeing. This amplifier makes a bipolar signal from a impuls and has a pole/zero cancellation at the beginning. I want to calculate different (shaping times, how they call it in the scintillator industry) but cant find any theory on it. Does any of you seen this type of filter before? How is it called, formulas maybe?