The digital time clock explained here is a circuit which most electronic amateurs would love to make. You might have heard about digital clocks made from clock ICs such as the popular LM8361, MM5387 etc but these ICs could be today quite obsolete and/or complex to build. Circuit Operation The present design is much easier […]
Simple
Simple Cellphone Jammer Circuit
This is a RF jammer designed for the U.S. 800 MHz cellular phone band (870-895 MHz). This works by generating an overwhelming sweeping RF carrier on the cell phone handset’s operating frequency range. Circuit Operation An Exar XR2206 Multi-purpose Generator is going to function as the triangle wave generator for supplying the sweep part of […]
Make this Simple Music Box Circuit
This simple circuit can be used to emulate the operation of a music box. The number of notes may be limited to 10 at the most, and therefore is capable of generating a simple melody. By: Akanksha Rathode Circuit Operation The circuit uses two popular integrated circuits: The timer 555 and 4017 decade counter Operation […]
Simple Thermostat Circuit Using Transistors
The electronic thermostat explained here can be used to control the room temperature by appropriately switching (turning on and off) a heating device. By: R.K. Singh Operational details of electronic thermostat The circuit employs a thermistor NTC (negative temperature coefficient) as the sensor device. – As long as the ambient temperature stays higher than the […]
Make this Simple Set Reset Circuit using IC 555
In this post I have explained a simple IC 555 set/reset application circuit for activating or deactivating a relay alternately. Audio/Video Representation Circuit Operation This electronic set reset circuit is very simple, easy to implement and very useful. It can provide you many applications options in cases where it may be necessary to toggle (switch […]
Simple Shadow Sensor Alarm Circuit
This shadow detector circuit operates using two LDRs and effectively detects the difference between the light levels and triggers a loud audible warning siren. In circuits which uses a single LDR (photoresist), the detection may not be as sharp as with two LDRs discussed here.Operational details of the shadow detector circuit may be studied as […]