diy ultrasonic transducer

The circuit diagram of an ultrasonic mosquito repeller is presented. This circuit operates on the principle that sound frequencies in the ultrasonic range, above 20 kHz, can repel insects such as mosquitoes. It utilizes a Phase-Locked Loop (PLL) integrated...

This schematic illustrates a simple DIY solar cell phone or USB charger circuit. It is designed to charge any device that can be powered from a computer USB port, such as MP3 players, cell phones, and iPhones. The circuit...

This tremolo effect circuit utilizes the XR2206 and TCA730 integrated circuits, designed for electronic balance and volume regulation with frequency correction. The circuit is beneficial for stereo channels and can simulate the Lesley effect, also known as the rotating...

The heart rate measurement project utilizing fingertip photoplethysmography was constructed using salvaged components, specifically an infrared LED and a photodiode. Due to the nature of these parts, their specifications could not be provided in the article. The heart rate measurement...

Each unit can drive 10 LEDs in either bar mode or dot mode, with the ability to switch between both modes as detailed in the datasheet. The setup accommodates 21 LEDs of any color, with bright white LEDs being...

This document describes the construction of an RFID reader utilizing an Arduino (specifically tested with the Nano 3.0, although other models may also be compatible), a hand-wound wire coil, and various low-cost common components. RFID readers are devices manufactured...