Free Electronics Mini Project Circuits

Here we have presented a list of various mini electronics projects circuits that are published on this blog. This is page is more helpful for the visitors in getting an idea about the different electronics circuits that are present in this blog. You may click on any of the following list of projects to get detailed explanation about that particular project and its circuit diagram.

Electronics Mini Projects Free Circuits

Free Project Circuits from ElectronicsHub.Org

List of Electronics Mini Project Circuits:

Mini Project Name
Water Level Indicator: The Water Level Indicator employs a simple mechanism to detect and indicate the water level in an overhead tank or any other water container. It can be used in Hotels, Factories, Homes Apartments, Commercial Complexes, Drainage, etc.
Boolean Algebra Calculator: Boolean algebra calculator works as a portable calculator to simplify the Boolean expression on the fly. In our circuit, we use Boolean algebra simplification methods like the Quine-McCluskey algorithm to simplify the Boolean expression and display the output on the display.
Unbiased Digital Dice with LEDs: Playing with dice is an age old game. We all love to play with it too. Playing with dice needs us to pick up a dice and make sure that it is unbiased. Making a block as a dice and cutting it clearly to make sure that it is unbiased is all an old story.
Automatic Washroom Light Switch: We turn On the lights in our washroom when we enter it and turn them off when we leave. We sometimes forget to turn Off the lights after leaving the washroom.
Intelligent Unambiguous Night Lamp Switcher: We usually turn ON the lights in our houses and offices manually. We need to turn ON the lights only when it is dark.
Automatic Door Bell With Object Detection: If we install this automatic doorbell using object detection circuit, the circuit will automatically sense the presence of the person and it rings the doorbell.
Panic Alarm: This is a panic alarm circuit which can help us to intimate others regarding our bad situation without any delay.
Continuity Tester With Melody: A continuity tester is a device which tests the continuity of the wire at hand. It is an indispensable tool to check broken wires and undesired shorting of wires.
Auto Night Lamp Using High Power LED: Auto Night Lamp Using High Power LEDs is a circuit which turns ON the LED lights interfaced to it at night time and it turns OFF the lights automatically when it is day.
Thermistor Temperature Sensing Alarm: This circuit raises an alarm whenever the temperature crosses a certain limit.
Pull Pin Security Alarm System: This circuit helps us to get alerted when anybody picks our pockets or bags. The circuit is very helpful to prevent our goods getting pick pocketed.
Auto Turnoff Soldering Iron Circuit: This circuit helps the soldering iron to turn off automatically when it detects overheating and thereby avoids it from getting damaged.
Hot Water Geyser Controller Circuit: This circuit is made to turn OFF geysers as soon as our water gets hot and are ready for bathing.
Remote Operated Alarm Circuit: This circuit rings an alarm when you point a TV remote at it and press on any button. This can be used as a calling bell to call your assistant.
Fire Alarm with Siren Sound: This circuit alerts us when there is a fire accident at home by ringing a siren sound instead of a buzzer.
Automatic Railway Gate Controller with High Speed Alerting System: The main aim of this project is to operate and control the unmanned railway gate in the proper manner in order to avoid the accidents in the unmanned railway crossing.
Water Level Alarm Using 555 Timer: In this project, we are using a water level alarm using simple and low cost hardware using a 555 timer circuit. The aim of this project is to make a water level detecting alarm with simple and low cost hardware without compromising on the performance of the device.
Battery Powered Portable Light: The instant solution to the problem described is to have a handy battery powered portable light which we can easily carry to the place it is needed. It provides considerable amount of brightness required to do our daily tasks.
Speed Control of DC Motor Using Pulse Width Modulation: If we want to use any devices like microcontrollers or any other digital equipment for automating our DC fan speed, then this method will not work in general. A more efficient way to proceed is by using pulse width modulation technique to manage the speed of our DC motor.
Interfacing 16×2 LCD with 8051: Here, we have brief discussion on how to interface 16×2 LCD module to AT89C51which is a 8051 family microcontroller.
Car Parking Guard Circuit Using Infrared Sensor: This project circuit helps the person in the driving seat and gives an alarm if there is any obstacle or a wall while parking or while driving in reverse.
PWM LED Dimmer Using NE555: The Pulse Width Modulation (PWM) plays an important role in controlling the circuits. We use this PWM to dim the intensity of light of the LED.
Simple 100W Inverter Circuit: This is a small Inverter circuit which converts the direct current (DC) to alternating current (AC).
Lead Acid Battery Charger Circuit: Lead Battery is a rechargeable battery in the 1857 by gaston plante. The main advantages of Lead battery is it will dissipate very little energy (if energy dissipation is less it can work for long time with high efficiency),it has very low energy to weight ratio, it can deliver high current’s and very low cost.
Metal Detector Circuit: Metal detector is very common devices for checking the person in shopping malls, hotels, cinema halls to ensure that person is not carrying any explosive metals or illegal things like guns, bombs etc.
Monostable Multivibrator Circuit Operation: Multivibrator is an electronic circuit which will work as two stage amplifier operating in both stable and astable mode.
Interfacing16X2 LCD with PIC Microcontroller: This is a circuit which helps in interfacing 16×2 LCD to PIC18F4550 microcontroller which is of family PIC18F.
Battery Charger Circuit Using SCR: The battery is charged with small amount of AC voltage or DC voltage. So if you want to charge your battery with AC source then use this circuit.
Interfacing 16X2 LCD to AVR Microcontroller: This is a circuit which helps in interfacing 16X2 LCD with AVR Microcontroller. The Atmega16 belongs to the AVR microcontroller family.
FM Bugger Circuit: Here is small circuit with which you can listen to another people conversation from long distance using the normal FM radio set. This FM bugger circuit is kept in room where you want listen the conversation. You can listen to this conversation using the normal FM radio set.
IR Remote Control Switch: By using this circuit, we can control any house hold appliance with the help of remote. In this project, there are two parts – one is in transmitting section and the other is in receiving section. Receiving section will be in a stable position which is connected to any load and transmitter will act as a normal remote.
Simple FM Radio Jammer Circuit: This is a Jammer circuit which is used to block the signals. Jammer circuit produces the high frequency signal which will confuse the receiver of particular system from receiving the signal, even though circuit is working properly, user of the system feels that circuit is not working properly.
Mobile Jammer Circuit: This circuit is used to block the signals of cell phones with in the range of 100 meters. This circuit can be used in TV transmission and also for remote controlled toys or play things.
Simple Fire Alarm Circuits: Here are two simple fire alarm circuits which are used to detect the fire automatically and inform to the people immediately with an alarm.
Simple LED Blinking Circuits: These are the circuits which are mainly used for visual indication in any electronic devices, measuring and interacting with the process, displaying the pictures in TV or in any advertisement hoarding, etc.
Morse Code Generator Circuit: This is a circuit used to generate morse code. Morse code is very old and versatile technique to send text messages using wireless media.
Motion Detector Circuit: The motion detector is not only used as intruder alarm but also used in many applications like home automation system, energy efficiency system, etc. The motion detector will detect the motion of the people or objects and give the appropriate output according to the circuit.
Rain Alarm Circuit: Rain water detector will detect the rain and make an alert; rain water detector is used in the irrigation field, home automation, communication, automobiles etc. Here is the simple and reliable circuit of rain water detector which can be constructed at low cost.
Automatic Plant Irrigation System: Here is a simple project more useful in watering plants automatically without any human interference.
Understanding 555 Timer: Working of 555 Timer as an Astable Multivibrator and Monostable Multivibrator circuits. 555 Timer IC Pin Diagram and circuit diagram. Modes of 555 Timer IC.
Touch ON and OFF Switch Circuit: Touch On Off Switch Circuit diagram and its working, 555 Timer IC simple circuit are explained in detailed manner.
Automatic Street Light Controller Circuit Using Relays and LDR: Circuit Diagram and working of Automatic Street Light Controller Switch Using Relays and LDR. It automatically turns on and off street lights.

555 Timer IC Testing Circuit: This is a simple 555 IC testing-circuit which tests your entire 555 timer IC. So before using your IC, check immediately that your IC is good or bad by checking it.
Curtain Opener/Closer Circuit: This circuit will open and close the curtain of your home and office just by pushing a switch. So with the help of this unique circuit, we do not need to move from one place to open and close the curtain.

SR Flip Flop with NAND and NOR Gates: SR Flip Flop also known as SR latch is the most vital as well as broadly used Flip Flop. Get an idea about design of SR Flip Flop with NAND and NOR Gates.

JK Flip Flop using CD4027: CD4027 is a JK flip flop that is generally used for data storing. Get an idea about how to build JK Flip Flop with CD4027.

Wireless Switch Circuit using CD4027: This is a simple circuit which needs no physical contact with the appliance. In this circuit, all you need is to pass your hand above LDR to ON or OFF the switch.

Polarity cum Continuity Tester: With the help of this circuit, we can also identify that whether the components we are using in our circuit are good or bad before mounting them on the PCB.

Mains Operated LED Light Circuit: This is a simple circuit named Mains Operated LED Light which you can be made easily and install in your homes and will not only save resources but your energy and money will also be saved.

Reaction Timer Game Circuit: This is a simple circuit named Reaction timer game. It contains 10 LEDs are moving in a arbitrary fashion. And you have to target a particular LED given by your challenger.

USB Mobile Charger Circuit: Nowadays, the charging of your mobiles has been made easy with the help of USB outlets present in the Laptop and PC. For the charging of your mobile phone, this circuit provides you a regulated voltage of 4.7 volts.

Variable Power Supply and Charger: This is a circuit which helps to check or test your electronic projects. And also Mobile phone batteries can be charged with the help of these circuits. This circuit can work as an emergency light.

LED Lamp Dimmer Circuit: In this circuit, at the starting LED glow slowly, then grown brighter and once again slowly it became dim. The basis of the whole circuit is an operational amplifier IC named LM358.

Multiplexer and Demultiplexer: A multiplexer is a circuit that accept many input but give only one output where as a demultiplexer accepts only one input and gives many outputs. Get an idea about their circuit diagram and pin diagrams in this post.

Security Alarm Circuit: This circuit will help you to guard your precious documents as well as jewellery from intruders or theft. All you need is just to place this circuit in front of the locker or below the mat so when any unknown person come and walk over the switch, the circuit will trigger and sound of alarm comes.

Variable Voltage Power Supply from Fixed Voltage Regulator: Voltage regulator is used to get fixed voltage at the output without depending on the input voltage. Get circuit diagram and working of variable voltage power supply from fixed voltage regulator by clicking the link given here.

Understanding 7805 IC Voltage Regulator: IC 7805 is a DC regulated IC of 5V. It is very flexible and is employed in many circuits like a voltage regulator.

LED Christmas Lights Circuit: This is a simple circuit used to decorate your house by building christmas lights using LEDs. The lights will get ON at night and OFF in morning time.

LED Running Lights Circuit: This is a simple circuit consists of 9 LED lights in knight rider scanner mode.

Basic Logic Gates Using NAND Gate: We are all well known that NOT, AND, OR are the basic logic gates. Here we have shown how to design these basic logic gates using one of the universal gates - NAND Gate.

Construction of Basic Logic Gates using NOR Gate: Here, we have shown how to construct the basic logic gates - NOT, AND, OR gates using NOR Gate which is one of the universal gates.

Electronic Letter Box: This is a simple circuit which helps in finding out any letter dropped in our box by stopping the LED lights attached in this circuit.

Luggage Security Alarm: This is a simple alarm circuit which helps in ringing a warning alarm when someone tries to steal the luggage.

9 Way Clap Switch Circuit: This circuit helps you to manage your appliances in your home by just clap without moving from your bed.

Clap Switch Circuit for Devices: This is another simple but very useful circuit which helps to ON or OFF a device without moving from you place and also helps to control the speed of the electric devices like fan, etc.

Audio Equalizer Circuit: The circuit is used to change the tune/melody into a different pitch level by devoid of loss in the tune. It is mainly useful to music lovers.

12V to 24V DC Converter Circuit: This is another kind of circuit which helps to convert 12V DC current to 24V DC current.

Police Siren Circuit using NE555 Timer: This circuit produces a sound similar to the police siren. You may also get detailed information about pin diagram and internal block diagram of NE555 timer.

Mosquito Repellent Circuit: Here is the simple electronic mosquito repellent circuit which can produce ultrasound in the frequency range of 20-38 kHz, which can scare away mosquitoes.

Cell Phone Detector: Cell phone detector circuit diagram, theory, working and applications are explained here. It helps in mobile phones tracking which are used for spying.

Air Flow Detector Circuit: This Air flow detector circuit can be used to detect the flow of air in areas like car engine. It can also be used as temperature detector.

12v DC to 220v AC Converter Circuit: Here is a simple voltage driven inverter circuit which converts 12v DC signal to single phase 220v AC using power transistors as switching device.

FM Transmitter Circuit: Here we built a wireless FM transmitter which uses RF communication to transmit the medium or low power FM signal. The maximum range of transmission is around 2 km.

150W Power Amplifier Circuit: Here we designed a power amplifier circuit using push pull class AB configuration to derive a power of 150W to drive a load of 8 Ohms (speaker).

100W MOSFET Power Amplifier Circuit: A power amplifier circuit using MOSFET has been designed to produce 100W output to drive a load of about 8 Ohms.

7 Segment LED Display Decoder: This is the circuit diagram of display decoder which is used to convert a BCD or binary code into a 7 segment code used to operate a 7 segment LED display.

100w Subwoofer Amplifier Circuit: Here is the circuit diagram and working of 100w subwoofer amplifier circuit. A Subwoofer is a loudspeaker which produces audio signals of low frequencies.

Password Based Door Lock System using 8051 Microcontroller: This system demonstrates a password based door lock system wherein once the correct code or password is entered, the door is opened and the concerned person is allowed access to the secured area. After some time, the door would be closed. Read this post completely to get more information.

Digital Tachometer using 8051 Microcontroller: Here we designed a simple non contact tachometer using microcontroller which can measure speed with an accuracy of 1 rev/sec.

Digital Voltmeter Circuit using ICL7107: Here we designed a analog to digital converter working as a digital voltmeter using a low power three and half digit A/D converter ICL7107 having internal 7 segment decoders, display drivers, a reference and a clock.

8 Channel Quiz Buzzer Circuit using Microcontroller: We built the circuit using a microcontroller which scans the input from push buttons and displays the corresponding number on a display device.

5 Channel IR Remote Control System using Microcontroller: This article is aimed to design and demonstrate a simple 5 channel remote control system to drive five loads. This circuit works on the principle of IR communication.

Battery Charger Circuit: This battery charger circuit works on the principle of controlling switching of an SCR based on charging and discharging of battery.

Bidirectional Visitor Counter using 8051: This Bidrectional Visitor Counter Circuit using is helpful to count the number of persons entering or leaving a room and to display it on a screen.

Celsius Scale Thermometer using AT89C51: This Celsius Scale Thermometer works on analog to digital conversion principle.

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