Fire alarm using thermistor & NE555

jacky March 8, 2012 53 Comments
Description. Many fire alarm circuits are presented here,but this time a new circuit using a thermistor and a timer to do the trick. The circuit is as simple and straight forward so that, it can be easily implemented. The...
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Street light circuit.

admin March 8, 2012 220 Comments
Description. The circuit diagram present here is that of a street light that automatically switches ON when the night falls and turns OFF when the sun rises. In fact you can this circuit for implementing any type of automatic...
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Fire alarm circuit

admin January 21, 2014 127 Comments
Description. Here is a simple fire alarm circuit based on a Light Dependent Resistor (LDR) and lamp pair for sensing the fire. The alarm works by sensing the smoke produced during fire. The circuit produces an audible alarm when...
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High & Low voltage cut-off with delay& alarm

jacky March 8, 2012 101 Comments
Description. This straight forward circuit will protect electrical appliances from over voltage as well as under voltage. The circuit also produces an alarm when the power supply comes back. An ideal circuit for home to protect your valuable equipments...
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Simple battery charger circuit

admin August 13, 2017 22 Comments
How to make a 12V battery charger at home? Description  Here is the circuit diagram of a simple and straight forward 12 V battery charger circuit with diagram. This circuit can be used to charge all type of 12V...
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UJT Organ circuit

admin February 16, 2012 4 Comments
Description. Here is the circuit diagram of a simple yet interesting mini organ based on UJT 2N 4891 (Q1). You can produce the desired sound by pressing each pushbuttons. You have also the option to set each push button...
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Mosquito repeller power saver

admin February 16, 2012 7 Comments
Description. Almost all liquidator type mosquito repellers are rated 5Watts. It is a pretty energy consuming game  when these repellers are operated through out the night. Even though these liquidators are switched ON and OFF in discrete intervals there...
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Cat repeller circuit

admin February 15, 2012 5 Comments
With this cool cat/dog repeller circuit you could chase the cats  off  from any where you want. In fact, I designed this circuit to chase my cat from my computer table. Most of the animals like cats respond violently...
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Infrared Motion Detector Circuit

admin August 3, 2016 255 Comments
In this tutorial, we have explained how to build a DIY (Do It Yourself) Infrared Motion Detector Circuit using 555 Timer IC, IR Diode, 2 comparator IC’s and other associated components. An Infrared Motion Detector circuit can be designed...
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