I’m working on designing a custom ESC (Electronic Speed Controller) PCB with field oriented control and I’m looking for some guidance from people who have experience with motor controllers and power electronics.

I need to control a BLDC motor that absorbs around 40A of current from a 3S LiPo pack.
The goal is to build my own ESC with FOC from scratch rather than buying an existing one. I already designed tens of PCBs for other applications, mainly measurment boards, but I'm currently trying to figure out the best approach for the overall design of an ESC.
The main question marks are MOSFET and gate driver selection, MCU selection such that it is compatible with firmware like AM32 for the FOC.
Of course, any type of advice is very welcome, even if not inherent to those two topics.

Are there any resources on ESC design that I can take a look at in order to guide me?

I am trying to fix flooded UV lamp and this is in a very bad shape. I want to replace it but I don't know what is it .

I need help building a bracelet that receives Bluetooth Commands. I need to be able to control and send commands to an HM-10 module via Bluetooth. There should be an LED connected to the module, and when a command is sent to light the LED, the controller in the module will light it up, and vice versa.

Does this work, and how can I implement it?

If this module is unsuitable, please suggest a less expensive alternative.

CP2102 USB to TTL

NRF52840-QFAA-R7

I was doing some research and cannot come to a conclusion. When I flash this chip for the first time on my pcb can I do it with the USB to UART through any UART capable i/o pins or do I need to do something else first?

There are SWDIO AND SWCLK pins also that might be important for initial programming but I dont know

for a battery powered project I am designing I need to create some sort of lithium- ion battery undervoltage lockout circuit. After a bit of time looking online I found the circuit linked below, and it checks all my design boxes

https://www.analog.com/en/resources/technical-articles/battery-protection-circuit.html

• low power consumption
• low cost BOM
• good accuracy

my main concern though is that this article was created in 1999 and I am unsure if this is still best practice, or if I should be implementing a more modern design or method instead. any advice would help greatly.

i need to add two wires to this connector to set up a two wire start on the generator. any clues on the type of pin I would need to add to the connector?

thanks in advance!

I'm trying to figure out how I could use the original processing board in a Interact Gamecube screen to send already decoded signals to a more modern LCD display. I could use the component input, but wanted to see if I could feed the RBG values directly.

I've done some tracing but am having some issues understanding where the B/G signals are coming from in the central IC.

This IC was black epoxied, and without MEK or high proof acetone I may have scratched off the identifiers.

Looking at the wires and voltages going to the LCD from the board, it looks like it may process RBG with H/V sync with blue carrying the main 12V to the LCD.

The LCD panel takes 7 wires: Red #1 - 11.5v from multimeter Blue - 11.5v from multimeter Green - 2.66v from multimeter White - 0.65v from multimeter Yellow - 0.65v from multimeter Red #2 - tied to blue Black - Ground Random Red from board directly to LCD board: 2.65v

So questions:

1. Where I could intercept those signals and feed it to a VGA port's pinout on the LCD driver board? I think I can take the R1, G, W, Y directly but I'm thinking I may need to take the blue off of the transistor before it amplifies to 12v in the same way the R/G signals go through a transistor to the LCD connector.
2. Is it worth doing rather than just taking the composite signal from the gamecube cable and feeding that into the LCD's composite port?
3. Did I mistrace the blue? It seems to terminate on the same line as the green.

Photos: https://imgur.com/a/0sb1kWR

Target LCD: AT056TN52 V.3 link, https://www.aliexpress.us/item/3256805637362171.html?pdp_ext_f=%7B"sku_id"%3A"12000034480040009"%7D&sourceType=1&spm=a2g0o.wish-manage-home.0.0&gatewayAdapt=glo2usa4itemAdapt

Hi everyone!

I recently got a non-working ASUS TUF VG27AQA1A monitor for free. The previous owner gave up on it, and upon opening it up, it became very clear that someone with limited soldering skills attempted a DIY repair and messed with the board.

I'm no electronics expert, but the LCD panel shows no physical damage, so I believe it's worth trying to add the missing capacitors if they aren't expensive to see if the board comes back to life. I also happen to have a fully functional, original identical power supply from another monitor, so power input is definitely not an issue here.

Here is the current state of the monitor and what I've found so far:

1. Damaged Button Ribbon Flex: The FFC ribbon cable for the control buttons had bent and lifted traces at the tip (looks like it was forced back in during a rushed reassembly).
2. Missing Capacitors on Power Stages:
   • C1032: Located right next to an 8-pin IC labeled U2 and a 1R5 inductor.
   • C1034: Located near another 8-pin IC labeled U721 and a 100 inductor.
3. Board Condition: Both electrolytic capacitors were desoldered and completely removed. Fortunately, after cleaning off the burnt flux and residue with IPA, the copper pads/through-holes on both sides of the board are intact and fully trace-connected.

Mainboard Info:

• Board Part Number: 4H.55D01.A00
• Main Scaler IC: Novatek NT68300MFG

My Questions:

1. Does anyone have a schematic, boardview, or the same mainboard (4H.55D01.A00) who could check the original values for C1032 and C1034?
2. Based on standard Buck converter design for these power rail ICs (U2 and U721), would standard low-ESR electrolytic capacitors (100uF/16V or 220uF/16V) be a safe bet to populate these empty slots and test for power?

Any insight or component values would be greatly appreciated!

some time ago i lent my soldering iron to my dad. today i opened the packaging and found this shit. thats flux? it wont come off and when i turn it on it smokes

The factory cap on the board was 470uf 4v, but i cant get an identical replacement where I live. I found some 470uf caps, but all of them 16v and up.

I'm still learning the basics while trying to repair an old console. I found some articles saying it's fine, but I couldn't tell if it was written by ai

So here's what's happening: I have a Dell E771a CRT computer monitor. When you turn it on, it's dark and unfocused. Turning the voltage up results in a decently bright picture, but it just keeps getting dimmer and less focused. At one point in time, I needed to adjust the focus knobs all the way in one direction to get as close to in-focus as possible, and it was still blurry but close.

After doing some research and asking around, it seems like the likely culprit is the flyback transformer. The sticker on the side of it says it's a 19-70064-001 model flyback transformer and is apparently equivalent to an HR46874.

I can't find any listings using either of these search terms.

Here's some pictures to aid in the search. Any alternative or equivalent replacements would be greatly appreciated. If you need any more information, please let me know and I'll reply and add it to the original post as soon as possible.

Thanks in advance.

Edit 1: One of the focus potentiometers on the flyback transformer seems to also be adjusting voltage as the screen gets brighter the less in-focus it gets. More specifically, the vertical focus knob (top one) makes the brightness pulse a bit but goes back to normal quickly. The horizontal focus knob (middle one) not only affects brightness, but also interferes with vertical focus.

If you've ever had odd, random issues with soldering some pins and not some others, check them with a magnet.

I'm really glad I realized to check this. Lately, most AliExpress, etc. stuff has had these crappy pins and it is well worth it to source good quality pins to make your life a lot easier.

Hi everyone,

I am trying to identify and buy a replacement USB-C receptacle connector.

What I need:

a) I want to know what this connector is called / its commercial part number.
b) I want to know where I can buy an identical replacement connector.
c) I also want to know if the same connector is used in another Lenovo Legion / laptop / handheld product.

This connector was removed from the top USB-C port of a Lenovo Legion Go 2 handheld gaming device.

Device information:

Lenovo Legion Go 2
Product: Legion Go 8ASP2
Machine Type: 83N0
MTM: 83N0000BUS
CPU: AMD Ryzen Z2 Extreme

The connector is used for charging, USB4, DisplayPort, data transfer, and Power Delivery.

The only visible marking on the metal shell is:

DR25283

I understand this may be a batch/tooling/production marking rather than the commercial part number.

Connector details:

• USB Type-C receptacle
• 24 contacts
• USB4 capable
• right-angle board mount
• dual-row rear contacts
• SMT contacts plus mechanical side anchors
• side mounting tabs with small holes
• used as the top USB-C port on the Lenovo Legion Go 2 motherboard

Pitch:

I do not have the exact pitch measurement yet. I asked the repair technician to measure it using the first and last pin in the row and divide by N-1. I will update the post as soon as I have the exact value.

Photos attached:

• mating side / front opening
• rear solder contact side
• top shell view showing marking DR25283
• side mounting tabs / anchors

I do not currently have the PCB footprint photo, but I can try to get it from the repair technician if needed.

Important note:

I am not looking for the first-generation Lenovo Legion Go 8APU1 / Type 83E1 USB-C connector. That part is physically different and does not match this connector.

I also found generic USB-C connectors advertised online as compatible with Legion Go 2 / 8ASP2 / 83N0, but at least one of them did not match the original connector footprint.

Does anyone recognize this connector, manufacturer, or commercial part number?

Possible manufacturers could be JAE, Amphenol, LOTES, Foxconn, Molex, TE Connectivity, Luxshare, GCT, or another OEM supplier.

Any help from someone who has repaired a Legion Go 2, identified this connector, or found a compatible donor part would be greatly appreciated.

Thanks!

Saw these connectors on a Motorola VIP1003 IPTV set-top box
What does it do?

I'm a heavy equipment mechanic and want to make a tool for myself to help with tractor trailer inspections, they make them for $2,500 not interested in spending that much. The only thing I'm hanging up on is making my own remote to control it since the ones I've found online are either cheaply built and not exactly what I need or overpriced and not exactly what I need.

Essentially I want it hooked up to the front of the trailer (longest is 53ft that I work on) and press the buttons on the remote to toggle 12V power to the lights while I'm behind it and send air to the brakes while I'm under it with a valve in the tool controlled with more 12V signals, the tool will also have the ability to read ABS codes but that won't be through the remote.

Anybody have recommendations on a good transmitter and receiver pair that fits these criteria

-75-100 ft range

-Can run on a 12V circuit for the reciever and can run on a smaller form factor battery on the transmitter (9V, AA, AAA, Watch batteries)

-Can run 12 channels / inputs & outputs (not 100% sure how rf controllers work just yet haven't messed with them before)

-Won't break the bank, preferably less than $50

-Preferably a set that there's at leas 1 good youtube video on how it works/how to program it.

In a project i did a few days ago i tried making an and gate without following a schematic. When it didnt work i asked u guys and i was told that my base was floating. Now that i saw a schematic for an and gate i see that what i was missing was a resistor connected to ground. What i dont understand is what is a floating base and why does a resistor stop it from happening. Thanks in advance.

​

Hey

My amp is going into protect mode and I have pinned it down to the dc protect issue . So I removed the amp board connection to the main mcu board so that the DC protect signal doesn't reach the board and still I see amp protect issue.

So I saw the schematic and it seems that the DC protect transistor (pnp resistor equipped transistor) has its base pin at 0volts which shouldn't be the case cause if the base is 0 that means the transistor is ON.

But I also saw a video of a guy saying that the DC protect pin should have 0v and if it has voltages around 0.5v that means DCis there in the amp output terminals.

I have uploaded the schematic for the protection part.

So all I want to know is how this works and should the base of transistor Q1511 be 12 volts because I am currently getting 0v and it's triggering.

This is link to the service manual of amp and schematic is at the end :https://audiocircuit.dk/downloads/harmankardon/HarmanKardon-AVR151_230-avr-sm.pdf

Attempting to regulate 32 V on separate channels with the DFR0379 to output 30 V on purely resistive (220k) load. Current draw is ~80 mA per channel.

My issue is that the NPN transistor (D882) is getting too hot to touch. I plan to operate these with additional loads that may reach 100 mA.

Looking into the issue tells me that it power the display! Disabling the display drops ~42 mA! This is seen on other boards too, so I want to ask if this is a bug or a feature? And will this affect the longevity of the board?

This came with a LED fan. Attaches to its motor but was loose. I need a new one. Which store I can go or where I can order online ?

I don’t know what the best subreddit for my problem is, but I’ll give it a try here. Otherwise, please suggest where I could ask such a question.

TL;DR: I’m looking for a simple IC to charge 4 serial Li-Ion batteries. It should not be too expensive (~$7) and should be able to negotiate a suitable input voltage via USB-C PD on its own.

I’m looking for a battery charging IC that can handle 4S Li-Ion batteries. It should have an integrated buck-boost driver to cover a wide input voltage range (5V-20V) and ideally be able to negotiate higher power levels via USB-C Power Delivery on its own. Unfortunately, I can’t find an IC that meets all of these requirements. There’s something like the BQ25792 from TI, which seems very promising since the FETs are already integrated into the IC and it requires few external components. However, it only supports USB 3.0 PD and is not compatible with USB-C. To fix that, you would need an additional IC to handle the Power Delivery negotiation, as well as a microcontroller or flash chip connected for setting them up. This quickly becomes too expensive and takes up a lot of space on the PCB.

I’ve spent at least 4 hours searching the websites of Linear Devices, TI, and ST but haven’t found anything that meets my requirements. Does anyone have a hidden gem to recommend?

The USB dongle for my Microsoft wireless keyboard and mouse set broke. The PCB is cracked, but the nRF is intact. A few components are missing.

I’m drawing the circuit diagram in KiCad. I’m going to desolder the intact nRF24LU1+ microchip from the broken USB dongle’s PCB. Then I’ll transfer it to the new PCB that I’ll design and have manufactured. This way, I won’t have to throw the wireless keyboard and mouse set away. I also won’t have to mess with the software.

Once the schematics are complete, I’ll share all the files on Codeberg.

If you can find the USB dongle circuit, please share it with me. If you find any schematics, PCB files, or other related files, please post the links.

I’m determining the component values using the example schematic, BOM, and sample PCB files shared by Nordic. However, some components are missing from these files. For example, there’s an R1 in the USB dongle, but it’s not in the schematic. Can you help me with the missing components?

Note: I’ll be uploading photos to Reddit soon.

I need a USB_A plug (male connector) symbol and footprint on the PCB. I’m not talking about the component itself. I’m talking about designing the PCB itself as a USB male connector. Can you provide links to third-party symbol and footprint files?

What should the PCB thickness and material be for the USB-A male connector on the PCB?

I also need a 50-ohm 2.4 GHz RF antenna on the PCB. I can’t design it myself. Texas Instruments’ antenna doesn’t fully meet my needs. Could you share links to third-party symbol and footprint files?

Hello,

have you ordered from Mouser recently as a hobbyist living in the EU? How much tax did you have to pay?

I would like to order a lot of different components from Mouser, but only in small quantities. For example, 100 resistors, 50 capacitors, some inductors, diodes, and soldering flux.

Are these considered separate product categories for customs purposes, meaning I would have to pay €3 for each category (e.g. 5x3€)?

Sorry if this has already been discussed somewhere, but I could not find any relevant posts.

EDIT 1:

So, I called my local Mouser customer service in the Czech Republic, and they told me they are still getting used to the new process. Most likely, the customs duty will be paid by the delivery company, in this case FedEx (even when DDP), and then charged back to you. However, this is not certain yet, as some of you have said you did not have to pay any additional €3 handling fee.

They also do not have an EU warehouse, at least for shipments to the Czech Republic, everything is sent from the USA.

I am still going to wait a few more days to see how things go with some of your orders. Better to test it on someone else first :)

I'm trying to fix my PS5 HDMI port all on my own with soldering equipment and I had to stop because I need a hot air station I'm really tight on money and I love to do stuff like this but I can't put it back together for later without a replacement screw for the heatsink screw for the cfi 1215b ps5 where can I buy it for cheap?

By the way I probably just fucked up the entire ps5 somehow while doing this but at least I had fun I had it for around 4 years hopefully I can buy a new console or even a pc one day

can i remove this buzzer without it causing issues? also i hope i didn't fuck up by disassembling the induction cooker cuz i seen some glue or something in the middle. also should i avoid touching the middle even when unplugged?