50-W Stereo Analog Input Class-D Audio Amplifier with a small number of external components mounted on a circuit board that can be used to directly drive a speaker with an external analog audio source as the input; can also be configured as a 100-W, Class-D mono audio amplifier in PBTL mode.

High-performance ESP32-based smart CDI / motorcycle ECU with automotive 12V transient protection, flyback HV capacitor charging, isolated SCR firing, VR pickup input, analog sensors, and auxiliary low-side outputs.

This project is a battery charging circuit utilizing a MAX1551 chip. It features a USB and DC power input, with LED status indicators. The design is outfitted with necessary decoupling capacitors and resistors to ensure smooth operation. #project #Template #charger #referenceDesign #batterycharger #MAX1551 #template #bms #analog

Reference schematic recreation of the DSO138 DIY digital oscilloscope, including analog input conditioning, STM32 control/display circuitry, controls, and power input.

High-level modular schematic requirements for a Teensy 4.1 based RFID-triggered audio system with Bluetooth input, analog source selection, stereo amplification, and 12V to 5V power partitioning.

50-W Stereo Analog Input Class-D Audio Amplifier with a small number of external components mounted on a circuit board that can be used to directly drive a speaker with an external analog audio source as the input; can also be configured as a 100-W, Class-D mono audio amplifier in PBTL mode.

Automotive smart fuel pump controller with >12 V battery qualification, protected battery input, analog FSCM command following, 25 A current sensing, thermal/fault indication, blue/red LED signaling, and 5-second buzzer alert. Control and fault nets are explicitly terminated to avoid floating or undriven states; any intentionally provisional control nodes are weakly biased to safe defaults during refinement.

50-W Stereo Analog Input Class-D Audio Amplifier with a small number of external components mounted on a circuit board that can be used to directly drive a speaker with an external analog audio source as the input; can also be configured as a 100-W, Class-D mono audio amplifier in PBTL mode.

FlowState Headband EVT1 — 4-Channel EEG Calibration Device Closed-loop EEG neurofeedback headband for theta/beta baseline calibration. 4-layer mixed-signal PCB, 40x30mm. Core ICs: - ADS1299-4PAG (TI) — 4-channel 24-bit EEG analog front end, SPI interface, 250 SPS - nRF5340 (Nordic) — Dual-core BLE 5.3 SoC, 128 MHz app core + 64 MHz network core Key requirements: - Separate analog and digital power domains (dual LDO: LP5907 for AVDD, AP2112 for DVDD) - Split analog/digital ground planes with single-point connection - 6 electrode inputs (4 active + 1 reference + 1 DRL) with individual TVS ESD protection on each - LIS2DH12 accelerometer (I2C) for motion artifact detection - MCP73831 USB-C battery charging (300-500 mAh LiPo) - 2.4 GHz chip antenna or PCB trace antenna at board edge with 10mm keepout - Conformal coating for sweat/moisture protection Reference designs: - Analog front-end: TI ADS1299 EVM (SBAS499) - Digital/BLE: Nordic nRF5340 DK reference schematic Critical constraint: Microvolt-level EEG signals — analog input routing and power supply filtering are the highest-priority layout concerns.

Simple bus-powered USB audio interface for MacBook Air and Ableton Live using a USB audio codec, stereo analog input and output path, monitoring buffer stages, USB-C power and data connectivity, and low-noise PCB guidance.

50-W Stereo Analog Input Class-D Audio Amplifier with a small number of external components mounted on a circuit board that can be used to directly drive a speaker with an external analog audio source as the input; can also be configured as a 100-W, Class-D mono audio amplifier in PBTL mode.

- ESP32 DevKitC V4 (microcontroller) - 2x BME280 sensors (temperature, humidity, pressure) - 8ch relay board with 12VDC relays (NO/NC SPDT) - 12VDC power supply - USB connectivity - Various components (resistors, caps, opto couplers, op-amps, motor drivers, multiplexers) - 2x SPDT relay boards (for fan fail-safe) - 4x 2ch bidirectional level controllers (3.3V to 5V) - ESP32 GPIO 21 (SCL) to BME280's SCL - ESP32 GPIO 22 (SDA) to BME280's SDA - ESP32 GPIO 5 (digital output) to 8ch relay board input - ESP32 GPIO 25 (PWM output) -> Fan PWM (0-255 value) - ESP32 GPIO 26 (PWM output) -> Light PWM (0-255 value) - ESP32 GPIO 34 (analog input) -> Tachometer input (0-4095 value, 12-bit ADC) - Add a 5V voltage regulator (e.g., 78L05) to power the ESP32 and other 5V components - Add a 3.3V voltage regulator (e.g., 78L03) to power the BME280 sensors and other 3.3V components - Include decoupling capacitors (e.g., 10uF and 100nF) to filter the power supply lines - Ensure proper grounding and shielding to minimize noise and interference -- Power supply: - VCC=12VD Available, to be used for LM358P - 5V voltage regulator (78L05) - VCC=5V, GND=0V - 3.3V voltage regulator (78L03) - VCC=3.3V, GND=0V - 3.3V voltage regulator (78L03) - VCC=3.3V, GND=0V - Fan PWM boost: - Input (3.3V PWM): 0-3.3V, frequency=20kHz - Output (5V PWM): 0-5V, frequency=20kHz - LM358P op-amp (unity gain buffer) - VCC=5V, GND=0V - R1=1kΩ, R2=1kΩ, R3=1kΩ, R4=1kΩ - C1=10uF (50V), D1=1N4007 - 0-10V signal conditioning: - Input (3.3V PWM): 0-3.3V, frequency=13kHz - Output (0-10V): 0-10V, frequency=13kHz - LM358P op-amp (non-inverting amplifier) - VCC=5V, GND=0V - R5=2kΩ, R6=1kΩ, R7=2kΩ, R8=1kΩ, R9=1kΩ, R10=2kΩ - C2=10uF (50V), R11=10kΩ (1%) ------------------------------------ Fan PWM Boost (3.3V to 5V): 1. ESP32 GPIO 25 (PWM output) -> R1 (1kΩ) -> VCC (3.3V) 2. ESP32 GPIO 25 (PWM output) -> R2 (1kΩ) -> Vin (LM358P) 3. LM358P (Voltage Follower): - VCC (5

This circuit can take an analog input, control a DC gearmotor, sense its direction and cumulative number of revolutions, and turn on and off three LEDs, in whatever way it is programmed. It can be repeatedly reprogrammed through a connector on the PCB. Powered by six AA batteries, it economizes on power by disconnecting some components when they are not in use.

Arduino-based 14-Panel LED and Button Controller with Analog Ladder Input

Compact 2-layer ESP32-S3-MINI-1 piezo TX/RX board for a shared 3 MHz transducer node. Includes USB 5 V input, TP4056 single-cell LiPo charging, TLV75533 3.3 V regulation, ferrite-bead isolated 3V3_ANALOG rail, ~12 V pulsed TX boost rail, low-gate-charge NMOS transmit driver, clamp-protected RX input, 2-stage OPA836 analog receive chain, envelope detector, ADC interface, TMP117 I2C temperature sensor, and status LEDs. Layout intent: piezo centered, RX chain within 10 mm of PIEZO_NODE, boost section remote from RX, digital and analog partitioning, and AGND/DGND star connection near RX front end.

Single-channel Universal Input schematic with LM76202 field protection, AD7708 ADC measurement core, CD4066 mode switching, HC595 control mapping, and comparator-backed digital input support for DI, analog, 0-10 V, 0-20 mA, resistance, RTD, and thermistor modes.

ESP32-based universal inline analog signal conditioner with protected sensor input, DAC output, fail-safe NC relay passthrough, OLED UI, Bluetooth profile logic, and terminal-block I/O for automotive/bench use.

Pulse induction metal detector using an Arduino Nano, TC4420-driven IRF3205 coil switch, TL072 analog gain stages, LM393 detection comparator, 12V input power, and buzzer alert, optimized for low-noise sensing and separated analog/power grounds.

Teensy 4.1 based coffee machine control board with five 120VAC relay channels, thermocouple and RTD temperature inputs, analog divider inputs, UART breakout, and 5V power input.

Analog water-level controller using an LM31 liquid level sensor input and PEL00884 brushed DC motor drive. The circuit buffers and scales the ratiometric sensor signal, derives motor current demand versus water level, shuts the motor off at 100%, and lights a green full-tank LED.

This project is a reference design for a 2A Solar Panel Power Manager With 7.2V LiFePO4 Battery and 17V Peak Power Tracking based on LT3652 IC. It includes components like resistors, capacitors, LEDs, and a JST connector for power input and battery connection. The design caters to high input voltage applications and ensures efficient charging with minimal components. #project #LT3652 #ReferenceDesign #charger #BatteryManagement #solar #LiFePO4 #referenceDesign #bms #analog #template #reference-design

This project is a reference design for a 2A Solar Panel Power Manager With 7.2V LiFePO4 Battery and 17V Peak Power Tracking based on LT3652 IC. It includes components like resistors, capacitors, LEDs, and a JST connector for power input and battery connection. The design caters to high input voltage applications and ensures efficient charging with minimal components. #project #LT3652 #ReferenceDesign #charger #BatteryManagement #solar #LiFePO4 #referenceDesign #bms #analog #template #reference-design #polygon

This project is a reference design for a 2A Solar Panel Power Manager With 7.2V LiFePO4 Battery and 17V Peak Power Tracking based on LT3652 IC. It includes components like resistors, capacitors, LEDs, and a JST connector for power input and battery connection. The design caters to high input voltage applications and ensures efficient charging with minimal components. #project #LT3652 #ReferenceDesign #charger #BatteryManagement #solar #LiFePO4 #referenceDesign #bms #analog #template #reference-design

This project is a Lithium-ion battery charger circuit utilizing the LTC4054 integrated circuit. It includes input and output connectors, a charging current programming resistor, decoupling capacitors, and a charge status indicator LED. The design can deliver up to 800mA charge current. #project #Template #charger #referenceDesign #batterycharger #template #bms #analog #reference-design #polygon

This project is a reference design for a 2A Solar Panel Power Manager With 7.2V LiFePO4 Battery and 17V Peak Power Tracking based on LT3652 IC. It includes components like resistors, capacitors, LEDs, and a JST connector for power input and battery connection. The design caters to high input voltage applications and ensures efficient charging with minimal components. #project #LT3652 #ReferenceDesign #charger #BatteryManagement #solar #LiFePO4 #referenceDesign #bms #analog #template #reference-design