The following simple analogue frequency meter circuits can be used for measuring frequencies which may be either sine wave or square wave. The input frequency which is to be measured must be at least 25 mV RMS, for optimal detection and measurement. The design facilitates a relatively wide range of frequency measurement, right from 10 […]
Search Results for: 555
6 Best Ultrasonic Circuit Projects for Hobbyists and Engineers
In this post I have explained a 6 very useful yet simple ultrasonic transmitter and receiver circuit projects which can used for many crucial applications, such as ultrasonic remote control, burglar alarms, electronic door locks, and for listening to frequencies in the ultrasonic range which are normally inaudible to human ears. Introduction Many commercial ultrasonic […]
Simple Digital Timer Circuit with 2 Digit Display
This simple digital timer circuit can be used to obtain timing output through selectable ranges, which can be set from 0 to 99 second, with 1 second interval, 0 to 990 seconds with 10 second interval, and 0 to 99 minutes with 1 minute interval. All these timing outputs can be visualized and tracked through […]
Automatic Hand Sanitizer Circuit – Fully Contactless
In this article I have explained how to make a low cost yet fully automatic hand sanitizer dispenser circuit which will allow a touch-free or contactless dispensing of the sanitizing liquid on the user’s hands. This contactless hand sanitizer circuit facilitates the user to access the sanitizing liquid on hands automatically without the need of […]
Neon Lamps – Working and Application Circuits
A neon lamp is a glow lamp made up of a glass cover, fixed with a pair of segregated electrodes and containing an inert gas (neon or argon). The main application of a neon lamp is in the form of indicator lamps or pilot lamps. When supplied with a low voltage, the resistance between the […]
How to Kill Coronavirus with Ozone Gas Generator
In this post I have explained the basic construction of an ozone generator apparatus for disinfecting a closed premise from dangerous viruses such as coronavirus. Ozone is a tested and an officially recommended method of eliminating viruses and pathogens on outside surfaces. Viruses Cannot be Killed with Medicines The fact that makes a typical influenza […]