In this post I have explained how a landline telephone can be rigged up wirelessly with a small transmitter circuit, enabling easy tapping of the telephone, by transmitting the conversations to a distant FM radio appropriately set up for the listening. Circuit Description The circuit diagram for the Telephone Transmitter can be witnessed in the […]
New Circuit Projects
Difference Between Op amp and Comparator
In this article I have explained the main differences between op amp and comparator, and try to understand why op amps are not ideally suited to be used like compartaors. We also learn the main advantages of using compartaor ICs in comparator applications. Basically, you will find many electronic lectures or publications talking about using […]
Cellphone Controlled Plant Watering Circuit
In this article I have explained a couple of circuits that will allow automatic watering of plants and flower pots, even while the owner of the house is away from home, and the house is locked for many days. The first method is through a sound activated system which detects the sound from a cellphone […]
Vehicle Parking Lot Counter Circuit
In this post I have explained how to construct a vehicle counter circuit that can count the number of vehicles entered in a parking lot at office building, schools, libraries, restaurants, hotels etc. The proposed project can count up to 999 vehicles especially cars and two wheelers and it can even count long vehicles like […]
IC 7805 Variable Power Supply Circuit [5V to 15V]
Although, a 7805 IC is mostly used as a fixed 5 V voltage regulator, it is possible to configure a 7805 IC to produce a variable output from 5 V and higher, depending up the input DC supply. In this post I have explained a simple circuit network which can be used for getting an […]
Electronic Acupuncture Circuit [Bio-Stimulation Circuit]
In this article I have explained how to build an electronic acupuncture circuit, also called bio-stimulation circuit., and use it for a possible treatment of many common body ailments, without any side-effects. The unit, if built and implemented correctly can possibly provide impressive results in healing issues related to headaches, body pain, muscle pain, fatigue, […]