This flashlight triggered burglar alarm circuit will instantly switch ON an alarm as soon as it detects light from the burglar’s torch or flashlight. Burglars and thieves normally set out to steal or rob during nights, when it is completely dark, and depend on a flashlight to investigate the area. Our circuit is setup and […]
Newly Updated Circuit Projects:
Mains High Low Voltage Protection Circuit with Delay Monitor
In this post I have explained an upgraded version of my previous mains 220V/120V high-low voltage cut off protection circuit which now includes a delayed restoration of power for the load with 3 LED power status indicators. The idea was requested by one of the dedicated members of this website. Circuit Objectives and Requirements Main […]
Simple LDR Motion Detector Alarm Circuit
Here I have explained how to build a simple LDR based motion detector sensor circuit using ordinary parts such as LDRs and opamps, reasonably accurately. What are Motion Detectors Motion detector or sensor alarm is a device which detects the presence of a motion or movement within a certain fixed range and raises an alarm […]
Induction Heater Circuit Using IGBT (Tested)
In this post I will comprehensively discuss how to build a high power 1000 watt induction heater circuit using IGBTs which are considered to be the most versatile and powerful switching devices, even superior to mosfets. Induction Heater Working Principle The principle on which induction heating works is very simple to understand. A magnetic field […]
How to Use Transistors
If you have understood correctly, how to use transistors in circuits, you might have already conquered half of electronics and its principles. In this post we make an effort in this direction. Introduction Transistors are 3 terminal semiconductor devices which is able to conduct relatively high power across their two terminals, in response to a […]
How to Switch Two Batteries Manually using Opto Coupler
The following article explaining a dual battery changeover relay circuit was requested by Mr.Raja so that it could become possible to switch between his old and new inverter batteries automatically, eliminating manual interventions. Let’s read it in details. Technical Specifications “I bought a new 12v 110 Ah lead acid battery for the dc home lighting system. I had another 12v […]





