I have this colpitts oscillator circuit im planning to build but i do not have a 1 MHz crystal, can i just replace the crystal with an LC tank that is tuned for 1 MHz?
I want to modify my old MP3 player, but I don't have an expert or mentor to help me, so I search online but it doesn't seem to be there.
edit
i have corrected the mistake and now it's all good. Diode Inc.'s GCE marking in SOT-23-5 is a mosfet, Diode Inc's GCE marking in SOT-23-3 is a precision shunt regulator.
in short, the circuit creates a steady voltage and a switchable ground from a 120v-240v AC source to power an optoisolator to inform the power supply controller of whether there's mains voltage or not.
Original: I'm trying to draw up the schematic for the Lite-on versions of the Playstation 5 PSU and for the life of me I don't understand what's going on with this section of the PSU.
At a High level I get what's going on. When the 12v is applied, the AC from the bridge rectifier is turned into DC, knocked down by a series of resistors, then used to power (somehow) the sending side of an optoisolator (the other side of the opto sends a signal to the main PSU microcontroller)
More low-level, I can't make heads or tails of it. I'd also like to try and identify the component marked FC.
Hi, is there a specific method or type of extraction tool for this variety of JST?
As you can see, I’ve already broken off the left wing, and I can’t get it to budge by hand or with tweezers or chip extractors.
I was finally able to remove another of this same type after much difficulty and I can’t see any type of lever or release. At a loss…
I'm trying to get access to this board XLR vol to either clean it or replace but without success, the vol pot touches the main board and the main board touches the vol pot, any advice would be helpful
This is my first project trying to make something using pcb boards and soldering and I honestly have no idea what I am doing. So I am making a post just took look for any advice. In this project, I am just trying to make a speaker. I have a charging pcb a 3.7 V battery, a switch, an amplifier pcb, a Bluetooth pcb, and two small speakers. Here are the attached images of my wiring and soldering. This was my first time soldering and honestly my wiring is a mess. I probably made every rookie mistake under the sun.
I also managed to remove the metal connection from one of the speakers. Any advice is very helpful to me. Thanks in advance.
Hello, my graphics card (nvidia 3090) had a part break off while servicing it. I am trying to figure out if I am on the right track to getting it repaired.
The graphics card was shutting down my computer when fps rose too high during gameplay. I installed a graphite thermal pad to replace the old thermal paste. I inspected the pads on the rest of the card, they looked great.
A Surface Mount Device (smd) broke off during this process: https://en.wikipedia.org/wiki/Surface-mount_technology
I still have the part. It is very tiny, about 1x1x2 mm. I think I found where it came from as well, on the right side of the yellow oval: https://ibb.co/zzdCjZN
Bigger picture of graphics card: https://www.techpowerup.com/review/msi-geforce-rtx-3090-suprim-x/3.html. I think the damage is from the bottom left of the left picture (just above the connectors).
Basically I need the service described here: https://blog.silverpc.hu/2025/10/18/help-i-broke-an-smd-off-my-gpu-while-cleaning-is-it-fixable/
Am I right in thinking that I just need to find a solder service to reattach the part? Like a reputable cell phone repair store? I have no experience with this so sorry if that is obviously wrong.
I appreciate your help, thank you!
So i posted here a while ago regarding a Leslie 222 Pre-Amp schematic diagram and got absolutely flamed because it was straight AI. This drove me to actually know wtf is going on, so i grinded for a bit, and now Im back. I recently just got all of the parts I ordered and would like a final check on my basic pre-amp schematic before plugging anything in.
I do plan to switch the leslie by injecting DC voltage straight into T1 centertap (controlled by a switch and a DCDC converter) but will wait to do this after I am getting sound out of the speaker. This post is just about the audio signal chain; the DC injection side is a separate piece I'll sort out after this part is verified.
There is a drawing, but incase you cannot read my trash hand writing and poor schematic drawing skills, here is the brief explanation:
Keyboard → 330Ω series (R1) + 1N4148 clamp diodes to ±12V → C1 (1µF, DC block) → NE5532 pin 3, configured as a plain unity-gain voltage follower (pin 2 wired straight to pin 1, no feedback resistors) → pin 1 output → C3 (2.2µF, DC block) → 10kΩ audio pot as a post-buffer level control (wiper to output) → 100Ω series resistor (R4) → transformer primary.
100kΩ bias resistor (R2) from pin 3 to true ground — kept separate from supply decoupling.
±12V dual-rail supply (Mean Well RT-50B), 0.1µF decoupling at both supply pins.
Second op-amp half unused, tied off per standard practice (inverting/non-inverting pins jumpered, non-inverting input grounded).
Separate question: after tying two ~84Ω half-windings together at their common pins to form what should be a single ~167Ω secondary, I'm reading a dead short (0Ω) across the two outer pins instead of the expected sum. Does this suggest the half-windings are tied in the wrong phase/sense relative to each other, or is there another likely cause for a short appearing here?
I need it to be 20s of red, 5s of yellow, then 15s of green, but it's not working. I cant use arduino either... the buzzer system beside it is a different thing. What should I do? (Beginner)
Edit: can someone be straightforward on what I should do to get this working? 🥲
Hi! For a sequencer project, I need to connect these 12 push buttons to an ESP32, using a Ground-to-pin configuration (or at least that's what I'm thinking about). Now the problem is that the Esp32 devkitv1 doesn't have enough pins capable of reading pish buttons ins. I think I have two options here, and I'd like to know which one you think it's best and why:
Option 1: use a series of different resistors, an connect all the push buttons to one analog pins (3v -> push buttons sequence -> analog pin), given the different resistors values, I should read different currents on each button and therefore know what is being pressed. This seems kinda long to do, and I'm concerned that I wouldn't be able to read multiple buttons being pushed at the same time correctly
Option 2: connect the buttons, keeping the ground-to-pin configuration, to a MCP23017 I2C GPIO extension module, which should be able to handle all of them. I never used this module, but I have a couple from a box of scavenged electronics I found a year ago.
If you have another idea in mind let me know :)
Thank you all in advance
I tried to create sine waves using DDS and 8 bit R-2R DAC. The output waveform is like this instead of a sine wave is there anything I'm missing here?
Hello everyone, I'm new to KiCad and electronics and currently learning. I would like to know if this schematic works for my project. I need to power an ESP32-C5, some additional modules, and a screen (which is why I chose a buck converter). Are there any obvious mistakes in the USB-C input or the buck converter section before I proceed with the PCB layout? Thank you very much!
I removed the small display unit from an old Soda Stream machine. It isn't electrically connected to any other part of the machine.
I see two interesting components on it, see photos. I'm wondering what they are. They look like sensors of some sort, enclosed in glass. There are two of them.
Any ideas?
Can anyone recommend a cheap DC 🟰 Clamp Meter?
I’m looking to build a simple system to display text received from an external source, whether it’s serial or 8 bit parallel onto a TTL input monochrome crt. The circuit came from a board with an SAB-8275 chip and a 27c64 eprom for character generation with the outputs hooked to a PISO shift register. I have a basic idea of how the 8275 works but my main questions are: how would I go about building sync and dot timing circuitry for the rest of the character generator, and if it would be easier to have it driven by a microcontroller like an esp8266, an arduino mega, or a z80 which I have a couple of. I’ve attached a picture of the board I pulled the 8275 off of if it helps
I have this Home Depot Halloween animatronic and unfortunately the power cable got smashed. I am unsure of the exact cable to look for, so I was hoping someone could point me in the right direction. The cable says “Switching Adapter”
“Input: 100-240V -50-60Hz 0.5 A max”
“Output: 5.9V 2.0A”
I have attached pictures as well
Hi everyone!
So this is the schematic for the PSX PSU (SCPH-7002 model). I am trying to understand it as much as possible, but I am not an expert on electronics. I would love if some of you could help me understand the specifics of it some more, because in general I understand it, but I am lost in the details.
- Up until after the full rectifier bridge I get it: EMI filter and the bridge.
- Then there is this crazy embroidery of diodes, resistors and capacitors that lost me.
- The transformer has two spirals (sorry if this is not the word, English is not my mother tongue). I guess one to get the 3.3 resultant V and the other for the 8V exit.
- After the transformer I am also a bit lost, I get that I will have again some stabilization of the resulting voltages, but I don't get much.
- I understand that, after the bridge I have 300V in DC and the transformer will need AC, so there is this optocoupler that will recieve some feedback from the cold segment of the PSU (low voltage) to manipulate a transistor and create the alternating pulse (square form?) that the transformer needs, simulation the AC.
In summary, I am especially lost in the embroidery that is between the bridge and the transfomer, but any input on the low voltage segment would be appreciated too.
I am studying this on my own, so I still struggle to understand this complex connections, but I would love to. Especially in the embroidery I don't even get what is in serial and what is in parallel because there is just too much happening.
Thanks to all of you for any help you can provide and for taking your time to write an answer :)
Would greatly appreciate some help reviewing the schematic I'm designing for a custom camera flash. This is my first time doing anything like this so I was hoping to get some feedback before moving on to the layout stage. Some more details not contained in the schematic:
I would really appreciate any feedback on the overall schematic as well as the plan in general. Especially since this deals with some high voltage current I'd like someone with experience to take a look before I go any further.
Some of the parts I'm planning on using, like the 12V boost and USB-C charging boards, seem hard to source. I'm only able to find them on AliExpress really so if anyone has any experience with ordering parts from there please let me know if you think this is a good idea. Thanks!
I don't have enough fan headers on my motherboard for the amount of fans. I'm too impatient to wait/buy a fan splitter, so i've created this brilliance. I'd love to know 2 things:
Im pretty much a beginner when it comes to this stuff, so any help is great. My biggest fear of this is that the wires will break my PC due to limits im unaware of.
Im currently splitting 1 header into 2 fans, i believe it is wired in parallel. The fans are 3 pin. The gorgeous beige taped to the wall is a breadboard.
I think that the 3rd pin of the fan is responsible for monitoring rpm, and i heard that merging that 3rd pin is confusing for the pc. Because of this, i only have one fan connected to that 3rd pin.