r/Electronicsinindia

Helloo guys, a fellow designer here. I am building a custom macropad for myself. I have already built a trial version and am now moving on to the advanced version. Below are the components which i am thinking of using. Please guide me on how to do the wiring and if any changes are required.

1. ESP32C3 Seed studio

2. 2x3 Grid of Mechanical Switches

3. A battery, I dont which one to use so please help in that aspect also

4. A tft display- https://robocraze.com/products/smartelex-2-4-inch-tft-display-240-320-for-arduino-esp32-raspberry-pi?variant=48481303232736&country=IN&currency=INR&utm\_source=chatgpt.com

5. Link to the data sheet of the display: https://cdn.shopify.com/s/files/1/0559/1970/6265/files/2.4_inch_manual.pdf?v=1765955651

6. Diodes/resistors for the switches to prevent floating

I have attached the link to the display and attached the pinout for the esp32.

Happy Building

Hello, I’m looking for help with a digital electronics circuit project.

This is the circuit we currently have (image attached). I’m looking for help analyzing it — any advice, comments, or suggestions would be greatly appreciated.

These are the project requirements:

Using:

• Logic gates
• Combinational circuits
• Sequential circuits
• Flip-flops
• 1 push button
• Buzzer
• 7-segment display

I need to design a circuit with 6 inputs where, when any of them is activated, a 9-second countdown starts. Once the countdown finishes, an alarm (the buzzer) must turn on.

The push button should:

• Cancel the alarm activation if pressed during the 9-second countdown
• Turn off/cancel the alarm once it has already been activated

Any help with the logic design, circuit analysis, or implementation would really help. Thanks!

So I got my LG AW-Q18WUXA window AC 1.5 ton 3 star delivered to me by flipkart today. While checking for any damages, i found that a small section of the fins were bent/damaged. Should this be of concern? There is no major bending but I would like to know if this would create any serious issues in the long run, or effect cooling to much extent?

Hey everyone, I’m looking to buy an ac stabilizer for 1.5t split inverter ac. We currently have 2 ac stabilizer:

1. Vguard ve400 standard
2. Candes (don’t know the model, installed back in 2016)

I’ve shortlised these 3 stabilizers, would love to know if these are good and reliable!

Budget is 3-4k. If you have any suggestions, please drop them below!
Thank you.

Bunch of us friends were working on an EV prototype. These were the surplus spares that we had purchased still in unused condition. Anybody wants it then yeah please let me know.

The fuses were purchased for 900 per piece. I can give it for 400 each.

The Fotek switch was about 2K shipped from overseas. Can give for 1000 rs.

Ambrane's reputation took a serious hit after a Gyan therapy's video their power bank/charger combo that literally exploded under normal use also damaging more things around it . Like many others, I avoided Ambrane products after that, but out of curiosity, I went ahead and purchased their 25/30W GaN charger specifically to test its safety and design. To my surprise, it is actually quite well-made. Here is an overview of my findings:

Pros -

1. Transformer - The transformer secondary (safe DC voltage part) is triple insulated many cheap ones only the thin lacquer (enamel) on the wire itself for separation which has a high chance of coming in contact with the primary (high voltage AC counterpart) this transformer uses triple-insulated wiring for the secondary side. This provides a robust physical barrier between the high-voltage AC and the safe DC output (img2)
2. Synchronous Rectification - Instead of a schottky diode a proper synchronous rectifier is used for output rectification which basically uses a MOSFET with a control circuitry to the simulate a diode (ideal) nearly eliminating the voltage drop of a normal silicon diode (img3)
3. Creepage - Because it is very small and compact the thing i was also worried of AC-DC separation it was hard to do that ,but they have handled it pretty well by using a plastic part and a slot between it so the creepage distance might be small but it is well separated (img4) (img5)
4. EMI suppression - Most fly-back SMPS have a capacitor between the primary and secondary to provide a return path for high frequency common mode noise generated due to switching now since it is between primary and secondary it is safety critical so a specialized one should be used many cheap ones use a normal one to save on cost but this one uses a proper class Y1 (img6)
5. Power ratings - it does what it claims. refer to the image for more info (img7)

Cons -

The main drawback is the lack of primary-side EMI suppression. To save on cost and space (though the footprint would only have increased by ~15%), they omitted: (img8)

1. MOV (Metal Oxide Varistor): Essential for surge protection.
2. Class-X1 Capacitors & Common Mode Choke: These filter out high-frequency noise.

Why this matters: Without these, you might notice flickering on sensitive electronics (like monitors or TVs) or touch-ghosting on your phone if they are plugged into the same circuit as this charger.

Technical Observations

1. Fuse - instead of a glass fuse a box type slow blow fuse is used which is more reliable and has better manufacturing tolerances (img9)
2. Main IC - it is a OB2733V which according to it's datasheet is a PWM controller with a integrated 650v GaN MOSFET the datasheet does not mention the continuous drain current (Id) of the mosfet for some reason but it it mentions the wattage as - 25w meaning Ambrane is pushing it slightly at the 30W peak. It was also covered with some thermal clay for better heat dissipation (img10)
3. Construction- The Usb c port it is mounted on a separate board along with the communication IC which is not a good or a bad thing just a design decision (img11 & img12)

Final Verdict: 7/10

Surprisingly, it is a well engineered product even tough it lacks EMI filtering , the core safety features (insulation, Y-caps, and creepage) are all present and accounted for and the BIS certification appears valid

It is safe to use✅

Note: This is a completely different design from their failed power bank combo, and this teardown/analysis does not mean all other Ambrane products are either safe or unsafe. This analysis only applies to this specific 30W model

SriHome PTZ IP Camera: Hardware and Software Analysis

TLDR: The SriHome SH020 PTZ camera utilizes a budget-friendly hardware design centered on a 64M-bit (8MB) SPI flash for firmware storage and a general-purpose SoC to manage video encoding and two-way audio. The device operates on a standard embedded Linux stack, likely employing a proprietary application for network streaming and PTZ control, making it a target for custom firmware or UART access.

TEARDOWN Video
This post summarizes the identified components, their functions, and the likely software architecture of a disassembled SriHome PTZ IP camera.

I. High-Level Device Overview

The device is a Pan-Tilt-Zoom (PTZ) IP camera that provides video and audio surveillance over a network. It supports both wired (Ethernet) and wireless (Wi-Fi) connectivity and features night vision capabilities via an infrared LED array.

II. Hardware Component Analysis

The camera is comprised of several interconnected printed circuit boards (PCBs) and peripherals.

A. Main Camera Board (Black PCB - Logic & Imaging)

This board acts as the central brain of the camera, handling all processing, imaging, and audio functions.

System on a Chip (SoC) / Main Processor:

Component: IP101GR 1804S11 PDH8A5701 (likely a typo in previous query, likely an IP series chip from a company like iPiotek or similar).

Function: This is the primary processor. It runs the operating system, executes the main camera application, processes the raw data from the image sensor, encodes video (e.g., to H.264/H.265), and manages all other components on the board.

SPI Flash Memory:

Component: KH 25L6436F M2T-09G

Function: A 64M-bit (8 Megabyte) Serial Peripheral Interface (SPI) flash memory chip. This non-volatile storage holds the entire firmware for the device, including the bootloader, Linux kernel, file system, and the main camera application.

Image Sensor:

Component: Unmarked, square sensor in the centre of the board.

Function: The core imaging component that captures light and converts it into raw video data, which is then sent to the SoC for processing.

Audio Power Amplifier:

Component: S 8002A

Function: A Class-AB audio amplifier. Its presence indicates the camera supports two-way audio and can drive a small speaker.

Microphone:

Component: Small, circular metallic component.

Function: Captures ambient sound to provide an audio stream alongside the video.

Power Management:

Components: Various smaller ICs (HRXP, HRBP) and inductors (marked 2R2).

Function: These components form the power regulation circuitry (likely buck converters) to step down the input voltage and provide stable power rails (e.g., 3.3V, 1.8V, 1.2V) required by the SoC, sensor, and other ICs.

B. Power & Communication Board (Green PCB - I/O)

This board serves as the interface between the main camera board and the outside world.

Wi-Fi Module:

Component: Realtek RTL8188FTV

Function: A complete Wi-Fi single-chip solution that enables the camera to connect to a wireless network.

Ethernet Port Transformer:

Component: GR HB1601SNL

Function: A 10/100 Base-T transformer module required for isolating the Ethernet circuitry and ensuring signal integrity for the wired RJ45 connection.

Connectors:

RJ45 Port: For wired Ethernet network connection.

Micro USB Port: Provides 5V DC power to the entire device.

FFC Connector (White): A flat cable connector that serves as the main data and power bridge to the black Main Camera Board.

J4 Header (Unpopulated): A set of through-holes that are the most likely location for a UART (serial) debug port. This is a critical access point for low-level system interaction.

C. Peripherals

PTZ Motor:

Component: MAINTE W-24BYJ 5V DC Stepper Motor.

Function: Provides the physical pan and tilt movement for the camera, controlled by signals from the Main Camera Board.

Infrared (IR) LED Board:

Component: A circular PCB with multiple IR LEDs and a central light sensor (photodiode/photoresistor).

Function: Provides illumination for night vision. The light sensor detects ambient light levels and automatically enables/disables the IR LEDs.

III. Software & Firmware Analysis

Operating System (OS): Embedded Linux. This is standard for such devices due to its stability, robust networking stack, and extensive hardware support.

Bootloader: Likely U-Boot, a common bootloader for embedded Linux systems. It is the first software to run, initializing the hardware and loading the Linux kernel from the 25L6436F flash chip. Accessing the U-Boot console is often possible via the UART debug port (J4).

Networking Services:

RTSP Server: yg rtsp server 1.0 running on port 8554. This service is responsible for streaming the encoded video feed over the network.

Authentication: The RTSP stream requires authentication (returns a 401 Unauthorized error), indicating a user/password security mechanism is in place.

Other Open Ports: 843, 1300, and 8699 are open for various functions, which could include proprietary control protocols, discovery services (like the identified Arcserve), or VoIP-related functions.

ONVIF Support: The camera is likely ONVIF compliant to ensure interoperability with third-party network video recorders (NVRs) and video management software (VMS).

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drafted by Claude

SOLD

This is my 32 inch tv from samsung there is a motherboard issue but the motherboard is old and it will be tough to find these motherboard what should i do . I just want to use this tv with my laptop thats just it

Due to the Increased Storage IC prices and Supply chain shrinkage, new SBCs became too expensive.

So I am looking to buy some Used Single Board Computers (SBC) or System on Modules (SoM)

Preferences :

Raspi 4 or above

Jetson Nano

Raspi CM4 or above

Rockchip SoM or SBC with decent performance

If anyone is willing to sell their Boards, please DM