In this post I have explained 5 useful power supply failure indicator circuits which can be used to get an instant indication regarding an input power failure situation. This post includes the following 5 types power failure indicator circuits: Main Function The main function of the proposed power failure indicator circuits is to alert or […]
Newly Updated Circuit Projects:
Adjustable Voltage Regulator Circuit using LM324 IC with Over Current Protection
In this post I have explained how a single LM324 IC can be used to create an adjustable voltage regulator circuit with overload and over current protections. Basic Working A basic IC LM324 quad operational amplifier regulates an unregulated 28-volt input source to approximately ±0.02%, resulting in a 1 amp 0 to -20 V supply. The […]
Accurate Transistor Tester Circuits Explored
In this article we talk about a few simple yet accurate transistor tester circuits which can used to identify whether a transistor is good or bad. Note: Please test *only* BJTs and MOSFETs (enhancement or depletion) with these circuits. Simple Good/Bad Transistor Checker using a Single LED Do you have a lot of strange old transistors […]
How to Measure Very Low Current [Circuit Diagram]
Accurately measuring very low currents of a few microamps or less using a regular panel meter or multimeter is not feasible. To make such precise measurements, you need to employ an active circuit, like the one depicted here. This circuit low current ammeter circuit can be constructed as a self-contained unit or integrated into an […]
How to Use TTP223 Capacitive Touch Switch Module [Pinouts Explained]
In this article I have explained how to connect and use the TTP223 capacitive touch switch module. These modules work using 2.5V to 5V. They are all pre-debounced, all you need is to provide the DC supply across the VC and GND terminals, and you get an output in the middle. So it is really […]
Flashlight Activated Burglar Alarm Circuit
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 […]





