In this post I have explained the making of simple delay timers using very ordinary components like transistors, capacitors and diodes. All these circuits will produce delay ON or delay OFF time intervals at the output for a predetermined period, from a few seconds to many minutes. All the designs are fully adjustable. Importance of […]
Circuits
7 Simple Continuity Tester Circuits Explained
If you are looking for a simple circuit to test continuity of wires and long conductors, the explained 7 easy to build continuity circuits are the ones which you can try and might fulfill your requirement. What is a Continuity Tester A continuity tester is a device which is used for identifying the correct continuity […]
3 Simple Solar Panel/Mains Changeover Circuits
The discussed automatic change over relay circuit was requested by Mr.Karimulla Baig. The circuit normally charges the connected battery at constant current through the power received from the solar panel, and reverts to DC power from an AC/DC adapter in the absence of solar energy (during night time). Let’s the read the request in more details: Technical […]
5 Simple Alarm Circuits for Protecting your Home/Office from Theft
The following article discusses a few very simple intrusion detector circuits, or ant-theft alarms. The presented designs are easy to build yet extremely effective with the functions. How the Circuits Works An intruder alarm basically consists of a sensor and a trigger stages, which work together to produce the required detection. The sensor detects the presence […]
3 Simple DC UPS Circuits for Modem/Router
In the following article I have explained 3 useful DC to DC uninterruptible power supply circuits or DC UPS circuits for low DC to DC uninterruptible power applications The first idea below presents a DC UPS circuit can be used for providing back up power to modems or routers during mains failures, so that the broadband/WiFi […]
9 Useful LDR Circuits Explained
In this post I have explained 9 LDR circuit projects that uses LDR light sensor to trigger a load ON/OFF through a relay. These circuits are mostly triggered by the absence or the presence of light on the LDR. The circuits are built using transistors, op amps and LDR along with a switching relay. Let’s […]





