The ultrasonic hand sanitizer circuit detects the presence of human hand through reflected ultrasonic waves, and triggers a relay solenoid pump momentarily for dispensing the sanitizing liquid on the hands of the user. The project uses the popular HC-SR04 ultrasonic sensor module for the required sensing function. Using HC-SR04 The HC-SR04 ultrasonic sensor module is […]
Ultrasonic
Ultrasonic Fire Alarm Circuit using Air Turbulence Detection
The simple ultrasonic fire alarm circuit I have explained below detects a fire hazard situation by picking up the variations in the surrounding air waves, or the air turbulence. The high sensitivity of the circuit ensures that even the slightest of air turbulence created by a temperature difference or fire is quickly detected and an […]
How to Make Ultrasonic Remote Control Circuit
This ultrasonic remote control circuit can be used to switch and control any appliance ON/OFF through a relay in the receiver circuit. Written by: S.S. Kopparthy Using Ultrasonic Waves This circuit is a different one that uses ultrasonic sound waves whose frequency ranges from 40 KHz to 50 KHz. These waves can’t be heard by […]
How to Make Ultrasonic Directive Speaker Circuit
In this post I have explained the construction of a ultrasonic directive speaker system also called parametric speaker which may be used to transmit an audio frequency over a targeted spot or zone such that the person situated exactly at that spot is able to hear the sound while the person next to him or […]