This presented refrigerator door open alarm circuit which alerts you after a period of time whenever your refrigerator door is left open. This circuit becomes very handy, because in case the door is left due to carelessness may cause significant increase in the consumption and affect the life of the fridge. Circuit Operation This circuit […]
Simple
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 […]
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. 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 on and […]
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 Ultrasonic Sound Sensor Alarm Circuit using Opamp
This article discusses a simple ultrasonic sound sensor alarm circuit which may be appropriately set for detecting sound pressures well above the normal human listening capacity, that may range from 20 kHz and over. Ultrasonic Concept Ultrasound or ultrasonic sound waves was probably invented even before humans existed on this planet by a few of […]
Simple RGB LED Color Mixer Circuit using LM317 IC
In this post I have explained a simple LM317 IC based RGB 3 watt LED color mixer circuit, which can be used for demonstrating the color mixing effects of red, blue, green colors as specified in the standard color charts. The idea was requested by Mr.Praveen. Technical Specifications My name is Pravin, I work in […]





