The door security alarm circuit discussed in this article alerts the user whenever the door fitted with the circuit is opened or closed or even moved from its original locked position. Using a Reed Relay and Magnet for the Triggering The idea utilizes the very basic reed relay and magnet concept across the door and […]
Newly Updated Circuit Projects:
Arduino based DC Voltmeter Circuit – Construction Details and Testing
In this post, I will show how to construct a DC voltmeter using Arduino where the readings are displayed in 16×2 LCD. The proposed voltmeter design can read up to 30V with tolerance of +/- 0.5 volt. We are going to see how this setup functions and explore other possibilities we can accomplish other than […]
Bluetooth Car Ignition Lock Circuit – Keyless Car Protection
This circuit will allow the user to lock his car ignition using his phone Bluetooth, meaning the ignition can be locked/unlocked only through a specific code from the user’s cellphone Bluetooth. Overview In one of my earlier posts I have already explained how to hack a Bluetooth headset and use it for any desired switching […]
“WELCOME” LED Display Circuit
In this post I have explained how to make a chasing “WELCOME” display circuit sign board, which illuminates each alphabet sequentially until all the 7 alphabets are lit and then the whole display shuts off, the cycle continues permanently as long as the circuit is powered. Overview I have already discussed a similar concept explaining […]
MQ-135 Air Quality Sensor Circuit – Working and Interfacing with Program Code
In this article I have explained how to interface air quality sensor MQ-135 with Arduino. We will see overview of the sensor and construct a project which detects LPG gas leakage and see some relevant readings in serial monitor. What is MQ-135 sensor? MQ-135 is an air quality or air pollution measuring sensor device. It […]
How to Make a Transformer Winding Counter Circuit
In this post I have explained how to make a simple transformer winding counter circuit using ordinary LEDs and also through an advanced digital display circuit. The idea was requested by one of the dedicated readers of this blog Circuit Objectives and Requirements I want a circuit which counts a number of turns for winding […]