In this tutorial, circuit uses a PIR sensor to control an output load through transistor switching, but the main purpose of this circuit is to turn ON the output when motion is detected and when PIR sensor detects motion, it gives a trigger signal After that, the NPN transistor and PNP transistor work together as […]
5V 4A Power Supply Circuit using IC 7805 and Parallel Transistors
In this post, the below designed circuit gives a stable 5V DC output with high current up to 4A which uses the 7805 voltage regulator IC and multiple TIP41C transistors connected in parallel, because the normal 7805 IC alone gives around 1A current and we add external power transistors to increase the output current. Moreover, […]
12V Negative Voltage Regulator Circuit with Zener and Transformer
A 12V negative voltage regulator circuit gives a stable -12V DC output from AC mains supply, in many electronic applications, we need both positive and negative voltages therefore, this circuit becomes very useful. This 12V Negative Voltage Regulator Circuit with Zener and Transformer is useful in audio amplifiers, operational amplifier circuits, analog systems and dual […]
Low Ripple -9V Regulated Power Supply Circuit
Need a clean negative voltage for your project? Then this 9V negative power supply circuit is a perfect solution which provides low ripple output and stable performance, making it suitable for many DIY electronics applications. This circuit is designed to produce a smooth 9V negative DC supply from AC input which at first, steps down […]
How to Test SCR using LED and 9V Battery Circuit
This article is about simple SCR tester circuit, where we can use this circuit to check SCR is good or faulty. The circuit uses one 9V battery, one LED, three 100 ohm resistors and two push button switches. The circuit is very easy to build as it is also very useful for students, hobby users […]
Simple LDR Based Refrigerator Door Warning Circuit
In our previous post, we designed a Refrigerator Door Open Alarm Circuit with IC 555 but however, in this post, we design a Simple LDR Based Refrigerator Door Warning Circuit without using any IC. Moreover, this circuit helps to alert the user when the fridge door stays open for a long time, as this simple […]