The World Well being Group (WHO) recommends that everybody ought to rub their fingers with cleaning soap for a minimum of 20 seconds earlier than washing with water to stop transmission of the novel Corona virus, which is once more on rise, along with social distancing. The 20-second interval will be checked with wristwatches and the stopwatches on cellphones, however these will not be handy to make use of whereas washing fingers. This proposed circuit rings a buzzer for 20 seconds and switches on an LED for audio in addition to visible indication (for these with listening to points).
The writer’s prototype is proven in Fig. 1.
Obtain PCB and Element Format PDFs: click on right here
This venture will probably be printed in a number of weeks. If you wish to entry it now, consult with Electronics For You’s January 2023 Situation–print or ezine version.