Get Ready to Build Simple Electronic Projects on Your Own!

This article is for all those electronics enthusiasts eager to fidget with the basic components in electronics, available all around. So here are very simple yet interesting electronic projects. This article is a collection of simple electronic projects with PCB layout that are helpful for beginners, diploma students, and engineering students to do mini-projects. During practice, the implementation of simple electronic projects helps to deal with complex circuits. Therefore, we recommend beginners to start these projects as these are capable of working for them on their first attempt itself. Before proceeding with these projects the beginners should know how to use a breadboard and basic Components used in Electronics.

Simple Electronic Projects for Engineering Students

Here is the list of simple electronic projects for beginners and engineering students which are helpful for doing mini project works. These projects based on electronics, electrical, diploma, beginners, simple electronic projects without a microcontroller, simple electronic projects without IC, simple electronic projects using LED, simple electronic projects with transistors.

Simple Electronic Projects for Electronics Engineering Students

The following projects are simple electronic projects for electronics engineering students.

1). Crystal Tester

Crystal is used as an oscillator, to generate a high frequency. In all the major electronic projects crystal is used instead of a coil. It is easy to test a coil using a multimeter but it is quite tough to test a crystal. So in order to overcome this problem this simple project is designed using a few passive components for testing the crystal.

Circuit Components 

The required components of the crystal tester circuit include the following.

Circuit Connection

This electronic circuit consists of a crystal oscillator, two capacitors, and a transistor forming a Colpitt oscillator. A combination of diodes and capacitors is used for rectification and filtering respectively. Another NPN transistor is used as a switch to make the LED glow.

Circuit Diagram & Its Operation

The entire circuit is operated with two transistors, two diodes, and few passive components. If the testing crystal is good then it operates as an oscillator in combination with a transistor. The diode rectifies the output of the oscillator and the capacitor filters the output. This output is now fed to the base of the transistor and the transistor starts conducting.

An LED is connected to the collector of the transistor through the resistor. The LED gets proper biasing and starts emitting light, i.e. it starts glowing. In case of any fault occurring in the testing crystal then the LED does not glow.

2). Battery Voltage Monitor

This electronic project is used to monitor the charging and discharging of the battery such that the battery voltage doesn’t exceed the specified level of that battery. It basically acts as a controlled battery charger. It indicates the state of the battery.

Circuit Components 

The required components of the battery voltage monitor circuit include the following.

Circuit Connections

The circuit of the battery voltage monitor is implemented using an operational amplifier IC (LM709) which is used as a comparator. Here a bi-color LED is used to indicate the status of the battery. A combination of a resistor and a potentiometer is used as a potential divider.

The voltage at this potential divider is fed to the inverting input pin of the comparator. The resistor R3 and R4 are used as a current limiter of the LED.

Circuit Diagram & Its Operation

The entire electronic circuit is powered by a 12V battery. When the voltage level of the battery increases up to 13.5 volts, the voltage at the inverting input is less than the voltage at the noninverting input and the output of the OPAMP goes low. LED1 begins to emit red light which indicates that the battery is overcharged.

When the voltage level of the battery falls to 10volts, the voltage at the inverting terminal is less than the voltage at the noninverting terminal. The OPAMP output goes high. LED2 begins to emit GREEN light which indicates that the battery needs to be charged.

3). LED Indicator Light

This project is used to design an indicator using LEDs. It is an inexpensive electronic project and can replace the traditional indicators used in bikes and cars.

Circuit Components

The required components of the LED indicator light circuit include the following.

Circuit Connections

A 555 timer is used in astable mode to generate clock pulses. The trigger pin of the timer is shorted to the threshold pin. A BCD counter IC 7490 is used to indicate the pulse count by switching on/off the LEDs. The LEDs are connected to the output of the counter IC.

Circuit Diagram and Its Operation

The pulses generated by the 555 timers are fed to the clock input of the counter. The counter accordingly generates a high signal at each of its output pins based on the number of the pulses received. For a high signal at any output pin, the connected LED glows. When the counter starts progressing, the light appears to move towards left.

If the frequency of the pulses increases, then the light emitted by the LEDs appears to move in one particular direction. If the frequency is high then the LEDs appear to glow at an instant. Individual flicker is eliminated as the light appears to move left at a faster rate.

4). Electronic Dice

Dice is a cube that is often used in many indoor games. Clearly a dice needs to be unbiased. Conventional dices used often get biased due to certain deformations or any defects in the construction. Here in this electronic project, an electronic dice is built which will always remain unbiased and would provide an accurate reading.

Circuit Components

The required components of the electronic dice circuit include the following.

Circuit Connection

Here a 555 timer is connected in astable mode. A resistor of 100K is connected between pins 7 and8. A resistor of 100K is connected between pins 7 and 6. The output from the timer at pin 3 is connected to the clock input pin of the counter IC 4017.

The enable pin of the counter IC is grounded.  4 output pins (Q0 to Q5) are each connected to an LED. The 5^th output pin is connected to the reset pin 15 of the counter IC. This whole circuit is powered by a 9V supply.

Circuit Diagram and Its Operation

With proper values of the resistor and capacitor, the 555 timer generates clock pulses at a frequency of 4.8 kHz, i.e. a clock cycle of quite a low time period. When these pulses are fed to the counter, each output pin goes high according to the number of pulses.

The LED connected to each pin starts glowing as the pin goes high. In other words, the LEDs start glowing for each corresponding count. The switching of the LEDs is at such a fast rate that it cannot be perceived by the human eye. The counter resets automatically as the count advances to 7.

5). Electronic Thermometer

This is one of the simple electronic projects where an electronic thermometer is designed. It can be used for measuring a wide range of temperatures. This thermometer can replace the clinical thermometer used by doctors.

Circuit Components

The required components of the electronic thermometer circuit include the following.

Circuit Connection

A 9V battery is used as the DC power supply source for the entire circuit. A diode is used as a temperature sensor and is connected in the feedback path of an operational amplifier. The input voltage is fixed by VR1, R1, and R2 at the noninverting pin 3 of the op-amp IC1. The output from this IC1 is fed to the inverting terminal of another OPAMP IC2. The non-inverting terminal of this OPAMP is given a fixed voltage signal. The output from this IC is connected to an ammeter which shows the current reading which is calibrated to show temperature.

Circuit Diagram and Its Operation

The voltage drop across the diode changes with a change in temperature. At room temperature, the voltage drop across the diode is 0.7V and reduces at the rate of 2mV/degree Celsius. This voltage change is sensed by the operational amplifier. The output of the operation depends upon the voltage drop across the diode.

Here another Operational amplifier is used as a voltage amplifier. The output from IC1 is amplified by the operational amplifier IC2. The ammeter indicates the current amplitude of the output signal and this is calibrated to indicate the value of the temperature.

Simple Electronic Projects for Electrical Engineering Students

The following projects are simple electronic projects for electrical engineering students.

1). Electronic Motor Controller

This electronic circuit is designed for controlling the motor using electronic devices. It is more efficient than any electromechanically controlling device. This project is also designed to eliminate the problems of noise triggering and noise pulses. These types of electronic projects are very simple and easy to be constructed and implemented. Here, we have demonstrated lamp intensity control instead of motor control.

Circuit Components

The required components of the electronic motor controller circuit include the following.

Circuit Connection

The secondary of the transformer is connected to the diodes. The diode D1 and D2 are used for rectification and the capacitor is used as a noise filter of the switching circuit. Here 5 transistors are biased in common emitter mode. The transistors Q1, Q2, Q3 are used to detect any fluctuations in voltage. The output of transistor Q1 is given to transistor Q2.

The output from transistor Q2 is given to the base of transistor Q3 and the output from transistor Q4 is fed to the base of transistor Q4. The collector of transistor Q5 is connected to a 2CO relay. A reverse-biased diode is also connected to the relay (at its other point). The resistor network R11, R12, VR1 form a current sensor circuit.

Circuit Diagram and Its Operation

The entire circuit is power by pressing the switch SW1. When the switch sw1 is pressed the transformer gets the mains voltage supply and converts it into low voltage. The current through the resistor R8 gives base current to the transistor T5.

When the relay gets activated the motors also switch on. The current sensor senses the logic high signal. When the transistor T4 receives a logic high signal from the current sensor, the R8 resistor gives a low signal to the transistor T5 and the transistor will not conduct.

As a result, the relay does not get energized and the motor is switched off. SW2 switch is used to switch off the motor. The transistor T4 gets on when the over and under voltage is given to the T3 transistor. The capacitor C2 and R10 resistor together form a low pass filter for avoiding noise triggering and pulses. It also provides sufficient time delay to the circuit.

2). Automatic Car Headlights Turn OFF Circuit

This electronic circuit saves the battery energy while the car ignition switch is turned OFF. It reduces the need for checking whether the headlights are ON/OFF. We can also vary the time for turn OFF the lamps by varying the potentiometer connected to the timer IC.

Circuit Components

The required components of the automatic car headlights turn off the circuit include the following.

Circuit Connection

This circuit mainly comprises of 555 timer IC, NPN transistor and the relay. Timer IC is connected in the monostable mode of operation. In this mode, timer requires a trigger input to generate the pulse with a certain time period. The output from the timer IC is connected to an NPN transistor. The collector of this transistor is connected to one terminal of a relay coil. Relay is used to control the ON/OFF periods of the lamp.

Circuit Diagram and Its Operation

An ignition switch acts as a triggering pulse to the timer. When the ignition is switched ON, a high logic signal is fed to the trigger pin of the timer and the timer doesn’t produce any output. The diode, as well as the transistor, don’t conduct. The relay coil gets energized as it is connected to proper supply and headlights get switched on.

When the ignition switch is turned OFF, a low logic pulse is given to the second pin of the timer so the output of the timer goes HIGH for a time period which is set by the RC values. The relay coil will be energized and the lamp will glow, but for a certain minimum time period and then will be switched off.

3). Fire Alarm Circuit

This simple electronic circuit is designed to give an alarm in the case when a fire breaks out. This circuit works on the principle that ambient temperature increases as a fire break out and this temperature changed is sensed and processed to give an alarm signal.

Circuit Components

The required components of the fire alarm circuit include the following.

Circuit Connection

Here a PNP transistor is used as a fire sensor and its collector is connected to the base of an NPN transistor through a series combination of a potentiometer and a resistor. The emitter of this NPN transistor is connected to the base of another transistor. The emitter of this transistor is connected to a relay. A diode is connected across the relay for back-EMF protection. This relay is used to control the switching of the load, which can be a horn or a bell.

Circuit Diagram & Its Operation

When a fire breaks out, the temperature increases. This causes the leakage current of the PNP transistor Q1 to increase. As a result transistor Q2 will be biased and starts conducting. This, in turn, brings transistor Q3 to conduction.

 The collector and emitter terminals of this transistor are shorted and current flows from the DC power supply to the relay coil. The relay coil gets energized and the load gets switched on.

4). Mobile Incoming Call Indicator

This circuit is designed to give an indication for incoming calls on a cell phone. This electronic project proves to be a relief from the nuisance created due to the sudden ringing of the mobile. There are many situations where we cannot switch off the mobile nor put it in silent mode, yet a loud ring can prove to be very embarrassing. This circuit proves to be a relief in such situations.

Circuit Components

The required components of the mobile incoming call indicator circuit include the following.

Circuit Connection

A coil is connected with a capacitor to the base of an NPN transistor. The collector of this NPN transistor is connected to the trigger pin of the timer IC555. This timer IC is connected in monostable mode with a resistor of 1M connected between pins 7 and 8. The output of the timer at pin 3 is connected to the anode of the LED and the cathode of the diode. This whole circuit is powered by a 9V battery.

Circuit Diagram & Its Operation

When the mobile receives an incoming call, its transmitter generates a signal around 900MHZ.  This oscillation is picked up by the coil in the circuit. As current flows from the coil to the base of the transistor, it conducts. As the transistor conducts, i.e. gets switched on, the collector and emitter are shorted and connected to ground.

 This gives a low logic signal to the trigger pin of the timer and the timer is triggered. A high logic signal is produced at the output of the timer. The LED gets proper biasing and starts blinking. This blinking of the LED indicates the incoming call.

5). LED Knight Rider Circuit

LED Knight rider running circuit is a light chaser or running light effect generator which produces forward and reverses moving effects. This type of lighting is used mainly in automotive applications and another sequential type of lighting application. It is one of the application circuits of IC 4017.

Circuit Components

The required components of the LED Knight rider circuit include the following.

Circuit Connection 

This circuit comprises of two IC’s i.e., timer IC and decade counter IC. 555 timer IC generates the clock pulses which are fed to the clock signal of the decade counter IC. The rate at which the lights are glowing depends on the RC time constant or clock frequency of the timer. Decade counter IC 4017 has ten outputs which go on high in sequence when pulses are applied at the clock input. These LED’s are connected through the diodes to produce the to and fro chasing.

Circuit Diagram & Its Operation

555 timer IC is connected in the astable mode so that it will continue to generate the pulses at a rate fixed by the RC values connected to it

These pulses are applied to the 4017 IC so the outputs of this IC are sequentially turned ON at rate fixed by the timer. Initially, the LEDs are switched on in increasing order and as the last LED gets switched on, the switching of the LEDs occurs in reverse order.

In other words, the first 6 outputs are connected directly to the LEDs to produce sequential switching of the LEDs and the next 4 outputs are connected to each LED so as to produce a reverse lighting effect. By varying the potentiometer at the timer we can get the variable rate of the LED’s switching.

Simple Electronic Projects for Diploma Students

The following projects are simple electronic projects for diploma students.

FM Transmitter

FM Transmitter allows you to send as well as receive any external audio source played through MIC with FM (frequency modulator) band. It is also called as RF (Radio Frequency) modulator or FM modulator.

When the audio from portable audio devices like iPod, phone, mp3 player, the CD player is connected to the FM Transmitter, then the sound from the audio device is broadcasted through the transmitter as an FM station. This is then picked up on your car radio or other FM receivers when the tuner is tuned to transmitted FM band or frequency.

This is the first stage wherein the converter converts the external audio source output to frequency signals. In the second stage, the modulation of the audio signal takes place by using the FM Modulation circuit. This FM modulated signal is then laid on an RF transmitter. So, by tuning the FM receiver or local FM devices one can hear the audio that is actually sent by the transmitter.

Circuit Components

The required components of the FM Transmitter circuit include the following.

• Q1 transistor-BC547
• Capacitor-4.7pF,20pF,0.001uF(has code 102),22nF(has code for 223)
• Variable Capacitor VC1
• Resistors-4.7 kilo ohm,3300 ohm
• Condenser/electrets microphone
• Inductor-0.1uF
• 6-7 turns using 26 SWG wire/0.1uH inductor
• Antenna -5cm to 1meter long wire for the antenna
• 9V Battery

Circuit Diagram & Its Operation

This circuit is used to transmit a noise-free FM signal up to 100meters by using one transistor. The transmitted message from the FM transmitter is then received by the FM receiver passing through three stages: oscillator, modulator, and amplifier stages.

By adjusting voltage controlled oscillator: VC1, the transmitting frequency of 88-108MHZ is generated. The input voice given to the microphone is changed into an electric signal and is then given to the base of the transistor T1. The oscillated frequency depends upon the values of R2, C2, L2, and L3. The transmitted signal from the FM transmitter is received and tuned by the FM receiver.

12). Rain Alarm

This circuit alerts the user when it’s going to rain. This is helpful for the home maids to protect their washed clothes and other material and things that are vulnerable to rain when they remain inside the home most of the time for their work.

Circuit Components

The required components of the rain alarm circuit include the following.

• Probes
• Resistors 330K, 10K
• Transistors BC 548, BC 558
• Speaker
• Battery 3V
• Capacitor .01mf

Circuit Diagram & Its Operation

The rain alarm begins to work and becomes operational when rainwater comes in contact with the probe, and once this happens; there is a flow of current through it, which enables the transistor Q1 that is NPN transistor. Conduction of the Q1 makes Q2 become active which is a PNP transistor.

Subsequently, the Q2 transistor conducts and the current flows through the speaker and the speaker alarms. Until the probe is in contact with the water, this process repeats again and again. In this system, the oscillation circuit changes the vibration frequency, and thus changes the tone.

Applications

The rain alarm system is used for

• Irrigation purposes
• Increasing the signal strength in antennas
• Industrial purpose

13). Flashing Lamps using 555 Timer

The basic idea here is to vary the intensity of the lamps at a frequency of one-minute intervals and to achieve this, we have to provide oscillating input to the switch or the relay that drives the lamps.

Circuit Components

The required components used in flashing lamps using a 555 timer circuit include the following.

• R1(Potentiometer)-1KOhms
• R2-500Ohms
• C1-1uF
• C2-0.01uF
• Diode-IN4003
• Timer-555 IC
• 4 Lamps-120V, 100W
• Relay-EMR131B12

Circuit Diagram & Its Operation

In this system, a 555 timer is used as an oscillator that is capable of generating pulses at a maximum of 10 minutes time interval. The frequency of this time interval can be adjusted by using the variable resistor connected between the discharge pin 7 and the Vcc pin 8 of the timer IC. The other resistor value is set at 1K, and the capacitor between pin 6 and pin 1 is set at 1uF.

The output of the timer at pin 3 is given to the parallel combination of a diode and the relay. The system uses a normally closed contact relay. The system uses 4 lamps: two of which are connected in series, and the other two pairs of series lamps are connected in parallel to each other. A DPST switch is used to control the switching of each pair of lamps.

When this circuit receives a power supply of 9V (It can be 12 or 15V as well), the 555timer generates oscillations at its output. The diode at the output is used for protection. When the relay coil gets pulses, it gets energized.

The common contact of the DPST switch is connected in such a way that the upper pair of lamps receives a supply of 230 V AC. As the switching operation of the relay varies due to oscillations, the intensity of the lamps also varies and they appear flashing. The same operation occurs for the other pair of lamps as well.

Simple Electronic Projects for Beginners

The following projects are simple electronic projects for beginners.

Single Transistor FM Transmitter

This mini project is used to design an FM transmitter using a single transistor. This circuit works in the range of 1 to 2kms range effectively. The input of this circuit is an electret condenser microphone that gains the analog signals. This circuit uses fewer components so one can build this circuit on PCB or breadboard easily. By using this circuit, the transmitter range can be increased by connecting the long antenna using wire.

Transistor Latch Circuit

The latch circuit is an electronic circuit used to lock its output. Once an input signal is given to this circuit, it keeps that state even after the signal is detached. The output of this circuit may be used to control a load using a relay otherwise just through the output transistor.

Automatic LED Emergency Light

This emergency light using LED is simple as well as cost-effective light including light sensing. This system uses main supply to charge and it activates once the supply is detached or turned OFF. The capacity of this circuit is more than eight hours.

Water Level Indicator

In electronics, this is a simple circuit used to detect as well as indicate the level of water within the tank. The applications of this project include Factories, Apartments, Hotels, Homes, Commercial Complexes, etc.

Solar Mobile Phone Charger

This project is used to make a phone charger using solar energy to charge mobile phones, digital cameras, CDs, MP3 players, etc. Solar energy is the best renewable energy that acts like a good power supply in bright sunlight.

But the main problem by using this energy is unregulated voltage because of a change in light intensity. To overcome this issue, a voltage regulator is used to changing the output voltage. The charge which is stored in the battery using solar energy can be given to different loads. The available charge can be illustrated on an LCD

Cell Phone Operated Land Rover

There are different controlling methods are available for a robot such as Bluetooth, Remote, Wi-Fi, etc. However, these controlling methods are restricted to particular areas & also difficult to design. To overcome this, a mobile controlled robot is designed. These robots have the ability of wireless control in a wide range until the cell phone gets the signal.

7 Segment Counter Project

In this digital world, digital counters are used everywhere. So seven segment display is one kind of best electronic component used for displaying the numbers. Counters are required in digital stopwatches, object or products counters, timers, calculators, etc

Crystal Tester

A crystal tester is an essential tool in electronics projects which works with high-frequency tools to produce a frequency of an oscillator. This circuit can be used to test & verify the crystal operation between the frequency ranges from 1MHz to 48MHz.

Some More Simple Electronic Projects

The following list includes simple electronic projects using a breadboard, LDR, IC 555, and Arduino.

Please refer to this link to know more simple circuit projects using a breadboard

Please refer to this link to know more simple electronic projects using LDR

Please refer to this link to know more simple electronic projects using ic 555 

Please refer to this link to know more simple electronic projects using Arduino

So simple and basic circuits, isn’t it? Don’t you find all these electronic projects worth to be implemented at your home or used as? Of course, I guess. So there is this one little task for you. Amongst all these projects, pick up one which catches your attention and try to make some changes in it. Please follow this link: 5 in 1 solderless project

Thus, this is all about the basic electronic projects for beginners to make the students learn about the components’ working and the way of implementing the projects. If you have any doubts regarding these projects or any other information regarding the latest projects and their implementation, you can comment in the comments section given below.

Photo Credits

• Electronic Projects for Beginners by staticflickr
• FM Transmitter Circuit by buildcircuit
• Rain Alarm Circuit by circuiteasy