In this article I have explained a simple walkie talkie circuit that can be easily built by any hobbyist and used for communicating between rooms or floors or simply for having some fun across neighbors and friends. The range of this system is around 30 meters. A walkie-talkie, also commonly referred to as handheld transceiver is […]
Wireless Circuits
Control a Relay ON OFF Using SIM Card, Mobile Phone, and Arduino
This project I will explain how we can control a relay remotely using a SIM card and a normal mobile phone, with help of Arduino and a GSM module. The relay can be turned ON or OFF by sending an SMS or by making a phone call to the SIM card placed inside the GSM […]
10 Simple FM Transmitter Circuit Diagrams Explained
An FM transmitter circuit is a high frequency wireless device which is able to transmit voice signals into atmosphere so that it can be received by a corresponding FM receiver circuit for reproducing the voice signals in a loudspeaker. Here we’ll discuss how to build small FM transmitter circuits using 10 different methods, one that […]
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 […]
27 MHz Transmitter Circuit – 10 Km Range
The 10 km range, 27 MHz transmitter circuit explained here uses citizen’s band which consists of 2 main types of users: radio control (R/C) modellists and users of low-power FM transceivers for local communication. However, here it is designed and intended for testing antennas and aligning receivers. It is actually an AM/FM quartz controlled for […]
2 Meter Ham Radio Transmitter Circuit
In this post I have explained the complete building procedure of a 2-meter amateur ham radio transmitter circuit, using ordinary electronic components and ordinary test equipment. What is 2-Meter VHF Radio The 2-meter amateur radio band is a section of the VHF radio spectrum, which includes frequencies ranging from 144 MHz to 148 MHz in […]