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So i built a outdoor hoop antenna to replace my cheap and crapy walmart antenna. IDK if the pre-amp fried the 5g/LTE filter or it wad my diy antenna. Is it possible for a 5g/LTE filter to stop working and filter out every channel. I orderd a new filter to see if it is the problem. Here is the antenna tutorial I followed: https://youtu.be/Tg0JjeotXq4 And the 5g filter: https://a.co/d/gwpNo2g

I recently got a nice deal on a stereo microscope, and leapt at the chance. I've had a few projects in mind that would entail SMD soldering, and now all I need is a proper soldering station.

Back in my day, you could usually sip a few mA from a USB2 port without any trouble.

Hi, my 3d printer psu fan gave up the ghost, and I wanted to replace it. It was pretty noisy, so I thought about upgrading from a 30mm to an 80mm fan. I am designing the top case with mounting holes, and want some input on where to place the new fan. The original placement is the box with the red color. The green and blue box are some options I thought of for the new fan placement. Would placing it over the busier part of the pcb yield lower temps, or is that a bad idea? Does placement even matter for psu fans? The new fan has higher airflow, but lower static pressure than the original one, and the plan is for it to always spin at a low rpm and occasionally speed up when the psu detects a high temperature. The original config runs it completely fanless until the psu reaches 50c and only then does it send voltage to the fan header.

I have a 750m 0.75mm² wire on a spool that needs a quick disconnect connector of some sort on it so it can take it off in 250m lengths. But it has to handle the tension of being spooled up. Any ideas?

Bought a new PC, and I was measuring its consumption out of curiosity. I noticed something weird (to me): when the PC is off (in fact, I completely disconnected the PSU and did the same test), there is quite some current running in the power cable to the PSU (0.15A).

I’m looking for a 5 pin connector type that I can easily find chassis plugs for both male and female.

Hello everyone, I bought a bottle dynamo for my bicycle with a rear and front light. Though I have one little tweak that I would like to add and that’s a way to keep it light up for about 1 minute (at least 30 sec) without pedaling. I thought of putting a capacitor in the circuit to store some energy but I would like what do you all think of it ?

Can I charge a 19V laptop from multiple USB ports?

I’ve been messing around with circuits my entire life but this design was time sensitive and I’ve never done my own PCB designs before, so I hired someone to put this together. After getting some test boards, when I plug them in the charger chip gets very hot and smells like burning…

I’ve been trying to solve an automotive electronics problem for several weeks now, but everyone I’ve spoke to can’t seem to come up with a solution.

I've recently been learning about superhet and frequency mixing and wanted to start tinkering. Specifically I'd like to try using two heterodynes in series to first frequency shift then uninvert the original audio, sort of like an analog frequency shifter.

I'm trying to achieve variable speed control on two brushed DC motors powered by a 3s or 4s LiPo battery (~12V or 15V). This is for a nerf blaster I'm modifying, which is why I'm not using a pre-made speed control ie I want control over the shape/layout. I'd like to vary projectile speed with a thumb knob.

I'm trying to build a very simple, stupid light switch for my grow light. Essentially, I want to turn on the light, if it gets too dark outside, so that my plants can survive the northern winter.

I have one of those basic motor kits you can buy off of Amazon. I was wondering what steps I should take to make it so that I can turn the motor on/off with the press of a button, wirelessly.

I built a Ploopy mouse yesterday. All the buttons work, and for the most part it's fine. But the movement is on and off laggy. Sometimes it works great, even faster than what I had before, and then it just stalls or stutters and slows down for a several seconds. I've tried a couple different USB cables, I've taken it apart and tried to reseat everything, I took the optic piece off and tried to blow out any dust that may have been in there. But it's still on and off laggy. Happens in windows and Linux both.

I have a foldable 120w one with 4 panels in sewn cloth. Gust blew it and the little plastic anti-tug box broke so wires could move.

Kind of an ELI5, but I tune a radion into a specific frequency to listen to a station. If that frequency is constantly being modulated (changed), how is the radio not going in and out of tune? I expect it is finding a way to measure multiple frequencies around the tuned station and decodes the data from it's deviation from the tuned frequency?

Hello,

I've got a VFD display on board along with UPD16311 driver is made for negative voltage around -30V and i think so is display (i couldn't find any info on display) and I'm doing it mostly from junk parts. I want to know what devices could/should contain power supply for such voltage. I've tried -12V from psu i've got lying around but it didn't work. There's also a chance that display itself is damaged but there's no visual sign of it.

I have a 3d printer in my car powered by a bluetti eb3a. The bluetti is charged by the 12v outlet in my car while driving. I have a 24v solar panel i want to mount to the roof of the car. My bluetti has only one dc 7909 input. So got a a Y splitter to combine power from the car and panel. But when plug it into the car outlet that turns off when i turn off the car, the solar panel turns on the stereo. Thats not the case with the outlets that are always on. I am worried that i will danage the car electrical system from a 24v solar panel flowing electricity back into the car?

I have a project that is using a Teensy 4.1, the cheep 5v regulator I was using in the project let the magic smoke out for no good reason. I replaced that but now the Teensy boots and runs for about a min then quits. There is a TLV75733P power IC that is supplying the 3v3 and it gets hot then quits supplying power. Since that IC is $0.46 vs a new Teensy 4.1 ~ $40 I want to try and replace it. I have done a bit of SMD work but not tried to remove a tiny chip with a GND pad before so I’m looking for any tips. The PCB of the Teensy has header pins so I can’t really get good contact to a hot plate to preheat the board.

I am working on a WLED project, using a esp32 in a 3d printed enclosere. But my dad says that i can't install it because it is not UL listed. He is worried if the house burns down, the insurance company won't insure it due to diy electronics possibly starting a fire. What am i to do, i am not developing a project to sell?

Hello !

I want to store a battery powered device long term (decades) as a reference article, it will never be switched on or charged again. The problem is that it contains a small LiPo battery that will be very hard to remove.

EDIT: Thanks everyone for you help, that has been very instructive. I think I just have a very poor quality cable adapter. Given that Blueretro is mostly an opensource DIY project, I’ll make a cable adapter myself instead of trying to fix what would obviously not function properly.

So my wife cracked the screen of her Playdate console. I got a replacement memory LCD (Sharp LS027B7DH01A), but the LCD is mounted with optically clear adhesive directly to a piece of glass which is adhered around the edges to the console’s faceplate.

I'm new to electronics and looking to assemble an array of components and tools for working on and designing electronics & circuits. Something immediately apparent is that all of the widely available kits orient you towards working with microcontrollers and SBCs; these kits are cool, but I want to have a halfway decent understanding of the underlying analog components and circuit design before I go digital.

Hi everyone

So, I've got a laptop screen that's giving up on me. 2/3 of the screen runs alright but the 1/3 on the left edge is acting weird. Half of the broken section displays an image but the image smudged and weird, while the other half is just dead. I opened it up to see what's up and, lo and behold, a wee tiny capacitor is missing (I know it's a capacitor 'cause I looked of the board marking, C248).

Does anyone have any advice on routing some high speed signals on flex PCBs? I'm looking at jlcpcb because of the low cost but I'm having difficulty getting impedances to be decent.

Hy I bought a cheap Yagi wifi antenna need some help cause the previous owner broke it and tried to fix it red neck style... It didn't work ... I hope I would be able to add a picture here is a breaf description anyway it's the cheapest brand you can find online the main element is formed into an oval shaped metal ring and here comes my question where should I solder the middle wire ? On one end ? On the other ? Should I pass it throu the (hollow) metal ring and weld it back to himself ? I have seen people build Yagies with similar ovaly shaped rings and they made the cable pass through half the ring and weld it there the problem is that my ring is shaped exactly like a C it doesn't have a second gap in the middle of the left part ... (Here=>C) English is not my first language hope it's good enough to be understood ask if not 👍🏻

I am looking for some sort of big programmable buttons. Not sure if something simple exists.

LEDs will conduct more current when they get warmer and differences between individual LEDs mean you cannot easily put them in parallel. A constant current DC supply will be good enough for part of the LEDs but will overload some others. To normalize current a series resistor is used with each individual LED.

Hello Lemmings, Hope you guys are doing well.

This is an idea that entered my mind. The traditional way is applying some etch resist like toner or dry film, etching away the copper and then adding solder mask before populating the board with components.

It appears to me that UV resin, used for SLA printers should be quite convenient for making PCBs with a laser etcher. You can spread a thin layer of resin on the board and quickly expose it using a laser engraver. It should be most convenient for silkscreen layers that are otherwise difficult to apply.

Seriously, what sadist saw a flat PCB surface, flat pick and place machine heads, and said "lets create a round component"?

Besides putting too many devices on a single wall socket, that draw too much power, what is supposed to happen?

I have a Mission MS 200 Subwoofer where the power supply has stopped working. I was quite happy with it, and would like to try to fix it, also I don't have the money for another. I have taken it apart and have narrowed the fault down to the PSU. I have visually inspected the solderings and components, and nothing obvious is wrong. I am not good enough to be able to reverse engineer the board, and was hoping there might be someone here with access to a schematic? Failing that, any pointers on where to maybe do some in-circuit measurements to narrow down which part(s) might be broken, would be very highly appreciated!

I'm trying to understand what's happening in this circuit:

I want to build a linux(yes i want linux specifically or a deritive of it) smartwatch as a prototype that lasts ~24 hours. Ive been looking for chips that are small and power effient enough but most of them cant run linux. If i have a 400mah battery that gives me a power budget of about 60mw... I know its possibly because there are wearos(basically android) watches that last 3-4 days. I dont know what kind of sorcery that is but that means it consumes about 15mw??? I really do feel like im miscalculating something but i checked multiple times. Do they hibernate linux/android and run it off of another chip. I also dont know how to excecute that properly and its kind of off topic of my question. So point is linux on a ~60mw budget in s smartwatch. I want to use a mip display as i really like the look and it uses little power but if ever want a heart rate sensor in it thats even more power consumpotion. Thanks in advance i guess if a saint answers this shitstorm of a question.

It happens rarely, but I will notice either my phone or the charger getting pretty toasty randomly. What could be causing this?

cross-posted from: https://sh.itjust.works/post/13637559

I work on equipment that runs off 3 phase 208V but it uses uses a transformer to drop it down to 120V for most of the controls. On this equipment I noticed that there are two fuses on the lines exclusively feeding the 208V side of the transformer and a fuse directly off of the hot side on the 120V side of the transformer.

Working on a joystick. Seems like any protocol I use to read from peripherals is going to be bottlenecked by having just one input. My microcontroller might have multiple ADCs, but there's just one processor stepping through them. Same for spi, or i2c, or uart. There's really only ever one sensor reporting back its data at a time.

I've recently bought a used computer, and it has a few problems. I'm looking for a guide to help me identify which parts are causing the problem.

Hello altogether, I guess everybody has some USB-C cables lying around, but wonder if it's 3A, 5A, 3.0, TB... Anybody able to recomment a device able to determine that? Maybe also something that can be combined with a load tester.

Since MOSFETs have a gate capacitance you'd want to limit the inrush of current from the output of a microcontroller to prevent it from getting damaged prematurely. That's what gate resistors are usually good for.

I'm an EE by trade focusing on embedded devices, but most of my work is in relatively low-power STM32 applications. When I stopped following developments in hobby kits, it was mostly Arduino Unos slowly driving I2C OLED displays.

Hi everyone!