9V battery-powered 555 timer LED blinker with on/off switch and hand-solderable through-hole parts. Uses a DIP-8 LM555 in astable mode with 47k/47k/10uF timing for about a 1 second blink interval, a 100nF decoupling capacitor, and a red 5mm LED with 680 ohm series resistor.

Simple 9V battery-powered NE555 astable LED blinker with on/off switch, red indicator LED, and hand-solder-friendly through-hole components.

9V battery-powered NE555 astable LED blinker (~1 Hz) with on/off switch; through-hole hand-solderable parts.

Battery-powered car vent clip fragrance diffuser with USB-C charging, motion-triggered wake, and open-loop timed heater control.

Battery-powered ESP32-WROOM-32 design with MAX30102 PPG sensor, MCP73871 single-cell Li-ion charging and power-path management, 3.3V regulation, and two low-current output terminals.

Battery-powered 555 timer LED flasher with on/off switch, timing network, and indicator LED output for simple oscillator testing and demonstration.

Architectural Lavender Translation Collar – ESP32‑S3 Wi‑Fi + LoRa, USB‑C, Li‑ion, low‑power design Overview Experience a cutting-edge IoT solution with this low‑power board built around the ESP32‑S3‑MINI‑1‑N8. Designed for seamless Wi‑Fi (2.4 GHz), BLE, and LoRa (868 MHz) connectivity, this board integrates ENS161 and ENS210 sensors over I2C alongside an RFM95W‑868 LoRa radio on SPI. It is powered via a 3.7 V Li‑ion cell with USB‑C charging up to 500 mA, complete with full battery protection, a robust 3.3 V rail tailored for Wi‑Fi burst currents, and per‑peripheral power gating to enhance energy efficiency. Core Features • MCU: ESP32‑S3‑MINI‑1‑N8 equipped with an onboard PCB antenna for 2.4 GHz Wi‑Fi/BLE, ensuring optimal wireless performance. • Sensors: Integrated ENS161 and ENS210 sensors utilize a shared I2C bus with controllable 4.7 kΩ pull‑ups for streamlined communication. • LoRa Radio: The RFM95W‑868 module, connected via SPI, enables long‑range communication at 868 MHz. Power & USB‑C Connectivity • Battery: A reliable 3.7 V 1200 mAh Li‑ion battery connected via a right‑angle JST‑PH 2‑pin connector features built‑in battery protection. • Charging: The USB‑C receptacle, with CC resistors and TVS protection on D+/D− along with series resistors, supports fast, safe charging with a current limit of 500 mA. • Regulation: A dedicated 3.3 V regulator capable of handling Wi‑Fi burst currents coupled with bulk and high‑frequency decoupling ensures stable operation, supported by status LEDs indicating power and charge states. Low‑Power Control • Peripheral Management: Load switches allow selective power‑gating of the ENS161, ENS210, and RFM95W modules, controlled directly by ESP32‑S3 GPIOs. • Energy Efficiency: Controllable I2C pull‑ups minimize idle current, vital for prolonged battery life in IoT applications. RF and Antenna Integration • 2.4 GHz: Utilizes the integrated PCB antenna on the ESP32‑S3 with proper ground/metal keep‑out zones for optimal signal integrity. • 868 MHz: Features a controlled‑impedance feed from the RFM95W to a PI matching network (C‑L‑C pads) with flexible antenna options—selectable via SMA connector, chip antenna, or PCB trace—and includes RF ESD protection. Connectivity & Debug Features • USB‑C Interface: Provides secure data connectivity with integrated safeguards and proper terminations. • Debugging: A comprehensive programming/debug header exposes EN, BOOT, and UART lines, with test points on key rails and buses (3V3, VBAT, SCK, MOSI, MISO, SDA, SCL, RESET/EN, GND) to simplify development and troubleshooting. Design Verification • Rigorous ERC/DRC and decoupling checks ensure adherence to component ratings and optimal signal routing. • Maintain RF keep‑outs and impedance‑controlled traces for both 2.4 GHz and 868 MHz paths, securing reliable performance even during high‑intensity operations. #IoT #ESP32S3 #LoRa #LowPowerDesign #USB-C #WirelessConnectivity #BatteryPowered #RFDesign

9V Battery-Powered 555 Timer Astable LED Blinker at 1 Hz (Through-Hole Design)

Battery-Powered Audio/Bluetooth System with External TP4056 Charging, Dual MT3608 Boost Rails, and Star-Grounded Power Domains

Battery-Powered MCU Sensor Board with Peripherals

Battery-Powered 2-Layer LM358 Analog Replicator PCB with Dual-Gain Edge Potentiometer and Solid 12 V Ground Plane

Battery-Powered IoT GPS Tracker — Power / Protection Review Summary (Updated)

Battery-Powered IoT MQTT Notifier with USB-C Power-Path Charging, Multi-Rail Power Architecture, and 3 s Long-Press PFET Power-Gate (MP5014 + LTC2955 + MCU SYS_EN Override) #power_control #long_press #load_switch #sys_en

9V Battery-Powered NE555 LED Flasher with SPST Switch

ESP32 Battery-Powered Wireless Data Logger with IMU, GPS, and IR Sensors

This project is a Lithium-ion battery charger circuit based on LTC4007 IC. The design incorporates n-channel power MOSFETs and extensive protection features for overcurrent, overvoltage, undervoltage, and overtemperature conditions. It is ideal for portable, battery-powered systems. #project #LTC4007 #ReferenceDesign #charger #BatteryManagement #reusable #module #bms #analog #template

This project is a Lithium-ion battery charger circuit based on LTC4007 IC. The design incorporates n-channel power MOSFETs and extensive protection features for overcurrent, overvoltage, undervoltage, and overtemperature conditions. It is ideal for portable, battery-powered systems. #project #LTC4007 #ReferenceDesign #charger #BatteryManagement #reusable #module #bms #analog #template

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #attiny2313 #TPS613222A #ISP #buzzer #reusable #module #simple-embedded #microchip #arduino #sublayout

XIAO MG24 Sense is an ultra-low-power wireless development board based on Silicon Labs' EFR32MG24 SoC, featuring a high-performance 78MHz ARM Cortex®-M33 core. It‘s Matter® native over Thread® and Bluetooth® Low Energy 5.3, all supported by the Arduino® Core. With 4MB Flash onboard, 19 GPIOs, LED, and charging circuit onboard, it boasts extremely low operating current and ultra-low-power modes, making it an ideal choice for IoT applications, especially battery-powered projects utilizing Matter® protocols. Additionally, the onboard analog microphone and six-axis IMU sensors make XIAO MG24 Sense a great fit for TinyML applications such as posture detection

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #attiny2313 #TPS613222A #ISP #buzzer #reusable #module #simple-embedded #microchip #arduino #sublayout

The APM2300CA, manufactured by Sinopower Semiconductor, is an N-Channel Enhancement Mode MOSFET designed for efficient power management in notebook computers, portable equipment, and battery-powered systems. This MOSFET operates with a maximum drain-source voltage of 20V and can handle a continuous drain current of up to 6A. It features a low drain-source on-state resistance (R_DS(ON)) of 25mΩ at V_GS = 10V, making it highly efficient for switching applications. The component is packaged in a compact SOT-23 form factor and is compliant with RoHS standards, ensuring it is both lead-free and environmentally friendly. Notably, the APM2300CA offers reliable and rugged performance, with a maximum junction temperature of 150°C and various gate charge characteristics that support fast switching. This MOSFET is ideal for applications requiring high efficiency and compact size.

This is a schematic of an IR (infrared) remote control system. It's built around a Microchip ATTINY2313 microcontroller (U1) and boasts five push-button switches, an indicator RED LED and an electret buzzer for user interaction. An ISP header provides programming capabilities. The project is battery-powered and implements boost converter TPS613222AD (IC1) for stable power supply. #project #Template #projectTemplate #lock #keypad #attiny2313 #TPS613222A #ISP #buzzer #reusable #module #simple-embedded #microchip #arduino #sublayout

The TPSM64404, TPSM64406, and TPSM64406E from Texas Instruments are highly integrated synchronous buck power modules designed for high power density and low EMI performance. These modules feature integrated MOSFETs, inductors, and controllers within a compact 6.5mm × 7.0mm × 2mm overmolded package, making them ideal for space-constrained applications. They support a wide input voltage range of 3V to 36V and deliver adjustable output voltages from 0.8V to 16V. The TPSM64404 offers dual 2A outputs or a stackable 4A output, while the TPSM64406 and TPSM64406E provide dual 3A outputs or a stackable 6A output, with the TPSM64406E rated for extended temperature ranges down to -55℃. These modules achieve peak efficiencies exceeding 93.5% and feature ultra-low quiescent current, making them suitable for battery-powered applications. Designed to meet stringent EMI standards, the modules include features such as dual input paths, integrated capacitors, spread spectrum modulation, and low-noise packaging. Additional functionalities include precision enable inputs, power-good indicators, overcurrent protection, thermal shutdown, and the ability to configure for multiphase operation up to 18A. The TPSM6440xx series is optimized for test and measurement, aerospace, defense, and factory automation applications.

The OPA835 and OPA2835 from Texas Instruments are ultra-low-power, rail-to-rail output, voltage-feedback (VFB) operational amplifiers. Designed for high-performance applications, these single (OPA835) and dual (OPA2835) op-amps operate over a power supply range of 2.5 V to 5.5 V. Consuming a mere 250 µA per channel, they offer a remarkable balance of power efficiency and performance, boasting a unity-gain bandwidth of 56 MHz, a slew rate of 160 V/µs, and ultra-low THD of 0.00003% at 1 kHz. Key features include a large signal bandwidth, negative rail input, power-down mode reducing current to 0.5 µA, and input voltage noise of 9.3 nV/√Hz at 100 kHz. Packaged options such as SOT-23, QFN, SOIC, VSSOP, and UQFN are available, accommodating a range of design requirements. The devices are ideal for battery-powered and portable applications, offering superior performance-to-power ratios for high-frequency amplifiers.