I want to replace a 4 fans setup in a plasma monitor and they are all wired into a single connector. I cannot find a direct replacement. What would be the solution here? I want to avoid soldering, I don't trust my skills, but if there is no other options, I'll do it.
Fans are Sanyo 109P0612T7F132 12V 0.1A, I would love to change them to quieter fans like Noctua.
Hello, I'm building a microphone preamp based on this schematic. My question is about protecting the output circuit. Say I accidentally plug it into the audio output of, say, a computer audio interface or electronic instrument instead of the intended audio input, this is likely to damage C4 due to reverse polarity, is that correct?
If so, I'm trying to think of ways to build protection into the circuit to prevent that from happening. Normally, I'd think to make an op amp buffer, but since this is a single supply this would rectify the AC signal.
Would a NP capacitor do the trick? That would be convenient seeing that those are so often recommended for audio circuits.
Thanks in advance for any advice!
Before you all judge me, this is my first time posting here, so please forgive me if this is a little awkward!
I’m currently learning about physical computing, and I had an idea for an AI-like robot. The problem is, I’m not sure if what I’m imagining is actually realistic or even possible.
At first I considered using an offline AI model, but I really want the freedom to customize how it works. Instead, I was thinking about creating a smart program that’s built from different information sources (like Wikipedia, for example) and can answer questions or have conversations with a specific personality.
Since it wouldn’t actually be AI, it wouldn’t learn or adapt in real time. However, I’d still like it to understand the general meaning of what someone says, even if it’s phrased differently. For example, if someone asks about the weather, whether they mention “weather,” “today’s weather,” or “what the weather is like,” the program should recognize they’re all referring to the same topic and respond appropriately.
From there, it could make simple logical connections for example, realizing it needs a location before giving a weather report. It could either make its best guess (with the possibility of being wrong) or ask a follow-up question like, “What location are you asking about?”
I’d also love to put this “brain” into a physical body. I’m thinking of starting with a small stuffed animal or electronic toy as a base, then modifying it with additional hardware and features.
My main question is: is something like this actually possible? Can you build a smart, AI-like program into a physical object without relying on cloud services or a huge company-backed infrastructure?
I know smart toys already exist, but I’m just one young person with a passion for building things.
Any advice, suggestions, or even reality checks would be greatly appreciated!
I’m sorry if this isn’t the Right community to post to, I’m not used to Reddit, if you have another one I should post this in please tell me!∩^ω^∩
Raspberry pi zero 2w suddenly stopped while in regular use. Using the sd in the image.
Was running as an IP camera, ran the whole night just fine, then put the same setup (with USB camera and powerbank for power) in my living room. Went out to do some errands for 1hr came home and the Pi was off, no led no nothing since then. Can't ssh, no HDMI output.
The sdcard is good, tried a sandisk one from my other pi zero and still same issue. Even with a fresh install. The gpio has power ie 3.3v and 5v show correct voltages. Gets a little warm like it used to before.
[ Please don't ask why I posted this here, I tried to post the same with/without image on the raspberry pi sub but the mods delete it immediately idk why. The rules are not helping either. ]
I need help from anyone who has experienced this. I can’t send SMS because it says, “Can’t connect to the network.” This module only supports 2G, while my SIM is 5G. As far as I know, the SIM should be backward compatible. Is there any way to make this work?
Also, AT+CREG? always returns 0,0 or 0,2.
+CREG: 0,0 = Not registered and not searching for a network.
+CREG: 0,2 = Not registered, but currently searching for a network.
I'm building a free browser-based electronics calculator workbench and I'm trying to make it genuinely useful for DIY electronics projects.
I'm aiming for calculators that include clear equations, units, assumptions, warnings, tolerance-aware inputs where useful, corner case outputs, guides, and worked examples.
Full disclosure: this is my project. It's called ECAD Workbench, and I can link it if that’s allowed, but I don't want to spam the sub.
The types of calculators I'm working on or considering include:
For people building small electronics projects, Arduino/ESP32 boards, battery-powered devices, sensor boards, repair mods, or custom PCBs:
First off. Yes. I'm quite aware I can literally go spend $200 and buy exactly this same thing. But I'm bored, I'm in my mid-40's, and I'd rather "create" something.
So I'm converting a hand pump sprayer (think weeds and RoundUp) into a battery powered setup. It's going to use a 12V/5A pump.
A VERY popular thing to do in this setup is to use your 20V DeWalt/Milwaukee/Ryobi whatever battery. Then you buy a BMS and a voltage regulator and wire it up and Bob's your uncle. Fine. I get that.
My question.
Why can't I just get a 12V lawnmower battery, add a fuse, and go to town? Then put it on a tender at night? I don't need to use it more than an hour once a month or so. So if I get a 12Ah battery I can use it an hour, then I'm down to 7Ah and I'm still above my 50% target for an AGM battery. Am I thinking of this wrong? I just put a V gauge on my setup then I quit when it gets to 12V, right?
In my caveman brain this seems simpler, so I'm sure I'm missing something.
I am working on a Arduino based project that drives a A4988 motor driver and Nema 14 stepper motor to randomly rotate the face plate of this fake fire alarm box I made.
I got it all working when plugged into the wall using a 12v 1A power supply but now that I have added a BMS, 3S 1A charging module and 3x 18650s it won't work.
I'm getting 12v from the battery pack and B+/B- on the BMS but no output on the P+/P- of the module.
I'm quite new to electronics so might have done something obviously wrong.
Any help appreciated!
Ikik VERY weird fucking question, but I'm building something to track the tongue's movements while the mouth is closed and I was curious what kinda components I can use.
I mainly wanna capture movement data for when people "talk" with their mouths closed, i.e. silent speech.
PS: if it wasn't clear I'm VERY new to electronics :3
EDIT: damn y'all are amazing with the responses, thanks a lot! :D
New to electronics I've started added lights to some model kids I've been working on, and one is having a problem unique enough that google thinks it's a handful of other problems.
I wired a model with LEDs and after a month they are less bright. I wired in a new set two months ago, full brightness, and they're back to being so dim I can barely see them.
- Power supply is 12V 1amp, plugged into a remote on/off switch into a wall outlet (US). I have changed power supplies once since I initially thought it might be the culprit. When I replaced all the dim LEDs I also changed to this new power supply.
- There are two types of LEDs, the model base has five [ultra bright LEDs](https://www.amazon.com/dp/B08GSMS6H2) pre-wired for 12V, I wired them parallel. They are not enclosed, they poke through a thin plastic base and then are then open air.
- The second set are [mini LEDs](https://www.adafruit.com/product/5487) are wired in series with a 300 ohm resistor, and are connected to the power supply is parallel with the other LEDs. These are in an enclosed space.
- All connection are soldered. Large LEDs use only the wires already provided with them, small LEDs are connected with a 30 AWG ribbon cable.
I'm sure the problem is simple and I've been one or two forum posts away from the solution, but so far it has escaped me. Sorry I don't have a wiring diagram, but at this point I'm worried I'd draw it wrong and add confusion.
Model is Nilson Works Monument Repair Type in case it comes up
A lot of fun to build. There are no transistors, Arduinos, or ICs, just simple switches and some clever wiring to give this robot the ability to avoid obstacles. Original circuit by Jérôme Demers.
Edit: As requested, here's a build guide.
Hello, I got this old fan and am trying to clean all the dust from it. Looking for suggestions on how to clean this dust-caked copper wire… deoxit maybe? I don’t do this kind of thing much so apologies if this is a dumb question
Hey so I am trying to fix the reverb on my solid state amp and I need help Identifying the right potentiometer i need to get so right now the effect works but its barely noticable when i turn it up all the way and my friend has the same model amp and his goes way out of control which is why i bought one so anyways I was looking to see what ohms it is and from what ive been reading it looks like its 750k but when i look it up it says its an uncommon value and just wanted to make sure I was reading it correctly the one side says 137-05-002 and the other is 1377750
I need to get it from Amazon but not sure how to search for it.
I’ve been working on a side project involving half‑wave inductive‑stress applied to a DC motor, and I wanted to share some of the results because the behavior is… unusual but repeatable.
Under load, the motor output voltage climbs all the way up to 282 V, even while the input voltage is falling.
This voltage‑rise happens consistently across multiple test points.
For comparison, I ran the exact same half‑wave stress on:
All of them collapse immediately under the same conditions.
Only the DC motor continues to rise.
I’ll upload the full set of photos showing:
Photos coming right after this post.
For anyone interested in seeing the real‑time behavior, here’s a short reference video (non‑commercial, just documenting the experiment):
More details and breakdown in the comments once I upload the photos.
R5 protects my Arduino output.
X3: L3 and L4 are my motor wires.
X3: L1 and L2 are external 12V/GND
What could cause my motor to be running constantly, even when the Arduino is powered off?
I am trying to take a motherboard of an old laptop of mine, acer swift 1, and I only want the motherboard. As if now you can only turn the laptop on using the on button on the keyboard which is connected through a ribbon cable. I tried to measure on which pins the on switch lies by pressing it and using a circuit with an LED to see if the circuit gets completed. (My first method was with a multimeter but none of the pins were connected there, as I think because it has to high of a threshold) . Between pin 14 and 15 and also 14 and 16 there was a light so something went through although the light for 14 and 16 was weaker. So I thought that I could now shorten pin 14,15 and 14,16 but it didn’t start.
Now I need your help to start the pc without the keyboard as I want to use it for a very tight project. It would even be enough if it wakes as soon as i connect it to power.
I have soime hobby projects, and need 18650s, where can i harvest them in toronto, does anyine have suggestions.
