ENGINEERING PROJECTS IDEAS

SNO	Electronics Projects
1	Water Level Controller using 8051 Microcontroller: Here we are designing the circuit which is used to detect and control the water level automatically in overhead tank using 8051 microcontroller. It is used in industries to control the liquid level automatically.
2	Car Parking Guard Circuit Using Infrared Sensor: This circuit helps the person in the driving seat in such a way that it gives an alarm if there is any obstacle or a wall while parking or while driving in reverse. It is very useful in our real life.
3	Cell Phone Detector: This is a simple circuit which helps to detect the presence of an activated cell phone by detecting the signals in the frequency range of 0.9 to 3GHz. It helps in mobile phones tracking which are used for spying.
4	Bidirectional Visitor Counter using 8051: This Bidrectional Visitor Counter Circuit is helpful to count the number of persons entering or leaving a room and to display it on a screen.
5	Password based Circuit Breaker: This password based circuit breaker project is built using 8051 controller and is used to switch off the power supply to the line by entering a password.
6	Temperature Controlled DC Fan using Microcontroller: The main principle of the circuit is to switch on the fan connected to DC motor when the temperature is greater than a threshold value.This can be used in home applications and in cpu to reduce heat.
7	Auto Intensity Control of Street Lights: This is a simple circuit that automatically controls the intensity of street lights which is designed using microcontroller and LEDs.
8	Line Following Robotic Circuit using ATMega8 Microcontroller: This line follower robot is a basic robot that follows a specific path indicated by a line having some particular width.
9	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.
10	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.
11	Bipolar LED Driver Circuit: This bipolar LED driver circuit is very useful at the places where flashing of light is required, as in beacon flashing. This circuit can be mainly used for indication purposes.
12	Celsius Scale Thermometer using AT89C51: This Celsius Scale Thermometer circuit is designed using at89c51 and lm35. This circuit works on analog to digital conversion principle. It can be used at homes, mobile places like cars to keep a track of the temperature.
13	Density Based Traffic Signal System using Microcontroller: In this system, we use IR sensors to measure the traffic density. We have to arrange one IR sensor for each road; these sensors always sense the traffic on that particular road. All these sensors are interfaced to the microcontroller. Based on these sensors, controller detects the traffic and controls the traffic system.
14	Automatic Washroom Light Switch: This is a simple but very useful circuit in our real life which helps to automatically turn On the lights when a person enters the washroom and it automatically turns Off the lights when he leaves it.
15	Automatic Door Bell With Object Detection: This automatic doorbell with object detection circuit helps to sense the presence of a person or an object automatically and rings the doorbell.
16	Water Level Indicator: This Water Level Indicator project employs a simple mechanism which helps 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.
17	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.
18	Boolean Algebra Calculator: This Boolean algebra calculator is an interesting project which is more useful in our real life by working 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.
19	Auto Night Lamp using High Power LED: This Auto Night Lamp is an interesting circuit which helps to turn ON the LED lights interfaced to it at night time and it turns OFF the lights automatically when it is day.
20	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.
21	Unbiased Digital Dice with LEDs: This is a circuit diagram of digital dice which is nearly unbiased. By using this circuit, there is no chance to cheat as the circuit operates at such a high speed that the circuit is almost imperceptible to the human eye.
22	Metal Detector Circuit: This is a simple metal detector circuit which is very useful 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.
23	Panic Alarm: This panic alarm circuit helps us to intimate others regarding our bad situation without any delay. It is more useful when an intruder entering our house or bad health status at which we are unable to intimate to the people around us.
24	Wire Loop Breaking Alarm: This circuit works as a continuity tester device which tests the continuity of the wire at hand. It is an indispensable tool to check broken wires and undesired shorting of wires.
25	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.
26	Automatic Plant Irrigation System: This project circuit is more useful in watering plants automatically without any human interference. It is more useful when the owner is not present in the home for few days.
27	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.
28	Lead Acid Battery Charger Circuit: Lead Battery is a rechargeable battery and is more useful in our real life as it will dissipate very little energy, it has very low energy to weight ratio, it can deliver high current, can work for long time with high efficiency and is very low cost.
29	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.
30	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.
31	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.
32	2 Digit Up Down Counter: The main principle of this circuit is to increment the values on seven segment displays by pressing the button. This circuit can be mainly used in scoreboards.
33	Bike Turning Signal Circuit: The objective of this circuit is to indicate left or right turn for bike/vehicle. Two identical circuits are needed, one is for left and the other is for right. The main heart of this circuit is 555 timer.
34	Automatic Changeover Switch: This is a simple automatic changeover circuit in which DC load like a series of LEDs are driven either by a battery or an AC-DC power supply.
35	UP/DOWN Fading LED Lights: This is a simple up/down fading LED lights circuit which can be used in shopping malls, home and security applications."/>
36	Police Lights using 555 Timer: This circuit simulates the police car lights by alternate flashing. This circuit flashes red LEDs for three times and blue LED’s for three times. This flashing action performs continuously. This circuit uses 555 timer and a decade counter.
37	PWM based DC Motor Speed Control using Microcontroller: Here is a simple DC Motor speed control circuit designed using AVR Microcontroller. Here we use a technique called PWM (pulse width modulation) to control the speed of DC motor.
38	Ding Dong Sound Generator Circuit: This is ding dong sound generator circuit is designed using 555 timer IC in astable mode. It can be used as doorbell. With some modifications, it can be used to produce different sounds. Read this post for complete details.
39	PIR Sensor Based Security Alarm: This article explains about PIR based security system in which PIR sensor is used instead of transmitter or receiver. This saves the power consumption and is low cost. This circuit can be used in the museums to protect the valuable things.
40	TV Remote Control Jammer: This proposed TV jammer circuit confuses the infrared receiver in a TV by producing the constant signal that interferes the remote control signal. If you switch on the circuit once, the TV will not receive any command from the remote. This allows you to watch your own program without anyone changing the channel or volume.
41	Super Sensitive Intruder Alarm: This circuit is designed to alert the user when an intruder enters into the home. If there is any obstacle in front of IR sensor, it generates an interrupt signal. This interrupt signal is given to the speaker to alert the user.
42	Remote Control Circuit through RF without microcontroller: Here we have used RF434 MHz modules to make wireless remote. Using this remote, we can control the appliances within the range of 100 meters. It is used for remote control applications like burglar alarm, car door alarm, calling bell, security systems, etc.
43	High and Low Voltage Cutoff with Delay and Alarm: This high and low voltage cutoff with delay alarm circuit is an advanced automatic voltage stabilizer circuit and is used to protect our home appliances. It's cost is less as compared to voltage stabilizers.
44	Solar Battery Charger Circuit: Here is the simple circuit to charge 6V, 4.5Ah rechargeable Lead-acid battery from the solar panel. This solar charger has current and voltage regulation and also has over voltage cut off facilities. This circuit may also be used to charge any battery at constant voltage because output voltage is adjustable.
45	Car Battery Charger Circuit: This article aims to describe the principle of operation, design and working of a simple car battery charger from AC mains supply and a feedback control section to control the battery charging.
46	Simple 100W Inverter Circuit: This is a small Inverter circuit which converts the direct current (DC) to alternating current (AC).
47	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.
48	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.
49	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.
50	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.
51	Intelligent Unambiguous Night Lamp Switcher: This is the circuit diagram of unambiguous night lamp switch, which turns ON our domestic lights automatically when it is dark, without human interference. It also avoids repeated frequent switching of the devices which is usually ignored in most similar circuits but may have a detrimental effect on our operating devices.
52	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.
53	LED Flasher Circuit: LED Flasher is a simple circuit which will blink the LEDs in regular time period. This circuit can be used for decoration purpose or can be used for a signaling purpose and many more.
54	Dancing Bi-Color LED Lights Circuit: Generally we use small voltage bulbs in the dancing bulbs. This circuit is mainly used in the occasions, decoration articles or in visual indication sign boards etc. In this project, we use bi-color LEDs for sequential running light.
55	Thermistor Temperature Sensing Alarm: This circuit is a temperature sensing as well as alarm circuit. The circuit raises an alarm whenever the temperature crosses a certain limit.
56	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.
57	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.
58	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.
59	Battery Charger Circuit Using SCR: Here is the circuit diagram of battery charger circuit using Silicon Controlled Rectifier. SCR can be used in half wave rectifier, full wave rectifier, inverter circuits, power control circuits, etc.
60	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.
61	Battery Powered Portable Light: This circuit is more helpful in handling unexpected and undesired darkness in our homes or offices. It provides considerable amount of brightness required to do our daily tasks.
62	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.
63	Cell Phone Controlled Robotic Vehicle: This is simple DTMF based Cellphone controlled robotic vehicle circuit without using microcontroller. It can be used in industries and surveillance systems.
64	Human Detection Robot using 8051 Microcontroller: The main principle of the circuit is to detect the human using human detection sensor. The wireless robot is operated manually using PC. The wireless technology used here is Radio Frequency technology. The data is transmitted to receiver through RF.
65	SMS Controlled Robot: GSM controlled robot or SMS controlled robot is a wireless robot which performs the necessary actions by receiving a set of instructions in the form a Short Message Service (SMS).
66	Remote Password Operated Electronic Home Appliances: This circuit explains you how to control the electrical appliances using an Android device. Here, Bluetooth module is interfaced to 8051 microcontroller. This Bluetooth receives the commands from the Android application device using wireless communication.
67	Metal Detector Robotic Vehicle: Land mines buried under the ground causes threat to the lives and affect the economy of the nation. Detection and removing of these mines manually is a dangerous task. So, we use a metal detection robot which works on RF technology.
68	Water Level Alarm Using 555 Timer: This is a simple and low cost hardware project using a 555 timer circuit. The aim of this project is to design a water level detecting alarm with simple and low cost hardware without compromising on the performance of the device.
69	Speed Control of DC Motor Using Pulse Width Modulation: This pulse width modulation technique is the more efficient way to proceed to manage the speed of our DC motor manually.
70	Sun Tracking Solar Panel: This article describes about circuit that rotates solar panel. This Sun tracking solar panel consists of two LDRs, solar panel, stepper motor and ATMEGA8 Microcontroller.
71	Touch ON and OFF Switch Circuit: This Touch ON/OFF Switch circuit is more useful in such a way that we can automatically ON or OFF any switch by touching a device without moving from our place.
72	USB Mobile Charger Circuit: This circuit is useful in charging the mobiles through USB outlet present in our laptops and PCs. For the charging of your mobile phone, this circuit provides you a regulated voltage of 4.7 volts.
73	Security Alarm Circuit: This circuit helps you to guard your precious documents as well as jewellery from intruders or theft. All you need is to just 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.
74	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.
75	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.
76	Automatic Street Light Controller Circuit Using Relays and LDR: This circuit helps in automatically turn ON/OFF the street lights using relays and LDR. The whole circuit is based on IC CA3140.
77	Battery Charger Circuit: This battery charger circuit works on the principle of controlling switching of an SCR based on charging and discharging of battery.
78	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.
79	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.
80	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.
81	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.
82	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.
83	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.
84	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.
85	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.
86	DTMF Based Home Automation System Circuit: This is a simple and very useful circuit in our real life named DTMF controlled home appliances system. It helps to control the home appliances using DTMF technology.
87	Street Lights that Glow on Detecting Vehicle Movement: This article describes about the circuit that switches the street lights on detecting vehicle movement and remains off after fixed time. This system controls the street lights using light dependent resistor and PIR sensor.
88	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, you may check whether your IC is good or bad by using this circuit.
89	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.
90	Variable Power Supply and Charger: This is a circuit which helps to check or test your electronic projects and also to charge the Mobile phone batteries. This circuit can also work as an emergency light.
91	LED Running Lights Circuit: This is a simple circuit consists of 9 LED lights in knight rider scanner mode. It will present an eye catching look as the LED initially travel in the one way and then travel reverse in the similar direction.
92	Luggage Security Alarm: This is a simple alarm circuit which helps in ringing a warning alarm when someone tries to steal the luggage.
93	9 Way Clap Switch Circuit: This circuit helps you to manage your appliances in your home by just clap without moving from your bed.
94	12V to 24V DC Converter Circuit: This is another kind of circuit which helps to convert 12V DC current to 24V DC current.
95	230V LED Driver: Here we design a simple circuit driving a series of LED from 230V AC. This is accomplished using a capacitor based power supply. This is a low cost and efficient circuit and can be used at homes.
96	3X3X3 LED Cube: This is a simple a simple LED cube circuit designed without using microcontroller. It is based on the principle of driving LEDs using the clock pulses.
97	Monostable Multivibrator Circuit Operation: Here is the monostable multivibrator circuit diagram and working. Multivibrator is an electronic circuit which will work as two stage amplifier operating in both stable and astable mode.
98	Interfacing16X2 LCD with PIC Microcontroller: This is a circuit which helps in interfacing 16×2 LCD to PIC18F4550 microcontroller which is of family PIC18F.
99	555 Timer in Monostable Multivibrator Mode: The circuit is triggered by a falling edge, that is, by a sudden transition from HIGH to LOW. The trigger pulse, produced by pressing the button, must be of shorter duration than the intended output pulse.
100	555 Timer as an Astable Multivibrator: In this circuit, There are three resistors named R inside it and all have equal values. These form a voltage divider having reference voltages of 1/3 and 2/3 of Vcc (the power supply). The logic state of the flip flop is controlled by the reference voltage which is given to one of the inputs of both two comparators.
101	Mains Operated LED Light Circuit: This is a simple circuit which is more useful to save our resources, energy and money by installing in your homes.
102	LED Lamp Dimmer Circuit: In this circuit, at the starting LED glows slowly, then grown brighter and once again slowly it became dim. The basis of the whole circuit is an operational amplifier IC named LM358.
103	Variable Voltage Power Supply from Fixed Voltage Regulator: This Voltage regulator circuit is used to get fixed voltage at the output without depending on the input voltage.
104	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.
105	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.
106	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.
107	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).
108	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.
109	Digital Temperature Sensor: The main principle of this circuit is to display the digital temperature value. These are mainly used in environmental applications.
110	Digital Stopwatch Circuit: This is a simple circuit that displays count from 0 to 59, representing a 60 second time interval. It consists of a 555 timer to produce the clock pulses and two counter ICs to carry out the counting operation.
111	Toy Organ using 555 Timer IC: This is the circuit diagram of simple Toy Piano using 555 Timer IC. It produces different tones or sounds depending on the frequency range.
112	RFID based Attendance System: This simple RFID based attendance system is designed using ATmega8 Microcontroller and is mainly used in educational institutions, industries, etc. where authentication is needed.
113	Low Power Audio Amplifier using 555 Timer: This is a simple low power audio amplification circuit designed using 555 timer. It can be used to develop low power music systems used in vehicles.
114	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.
115	Polarity cum Continuity Tester: With the help of this circuit, we can also identify whether the components we are using in our circuit are good or bad before mounting them on the PCB.
116	Reaction Timer Game Circuit: This is a simple and funny game circuit which contains 10 LEDs that are moving in an arbitrary fashion and we have to target a particular LED given by your challenger.
117	Understanding 7805 IC Voltage Regulator: This is a circuit diagram of 7805 IC which is a 5v DC regulated IC. It is very flexible and is employed in many circuits like a voltage regulator.
118	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.
119	Dummy Alarm Circuit: The main principle of the circuit is to flash an LED for every 5 seconds. The circuit consists of 7555 timer IC as main component.
120	Reverse Parking Sensor Circuit: If you are a new driver then it is very difficult to judge the distance while parking the car. Reverse parking sensor circuit solves this problem by indicating the distance with the help of three LED’s. We can easily arrange this system at the back side of the car.
121	Automatic LED Emergency Light Circuit: This is the simple and cost effective automatic emergency light circuit with light sensing. This system charges from main supply and gets activated when main supply is turned OFF. This emergency lamp will work for more than 8 hours.
122	One Transistor Electronic Code Lock System: The main principle of this circuit is that the door lock opens only when the buttons are pressed in an order. The transistor and diode plays a main role in the circuit.
123	Automatic Battery Charger: This charger automatically shut off the charging process when battery attains full charge. This prevents the deep charge of the battery. If the battery voltage is below the 12V, then circuit automatically charges the battery.
124	Light Activated Switch Circuit: The main principle of this circuit is to switch ON the light when the LDR is illuminated. This circuit can be used in security applications like when there is darkness on the LDR, it stops lighting.
125	Remote Operated Spy Robot Circuit: This is a simple spy robot circuit which can be controlled by the remote. The maximum controllable range is 125 meters. It is used to observe the behavior of wild animals where human beings cannot reach.
126	Digital Voltmeter using 8051 Microcontroller: This is a simple digital voltmeter circuit designed using 8051 microcontroller. This circuit measures the input voltage from 0V to 5V. Here, the input voltage should be DC voltage to get the accurate output on LCD.
127	Ultrasonic Rangefinder using 8051: This circuit explains you how to measure the distance using 8051 microcontroller. This ultrasonic range finder system measures the distance up to 2.5 meters at accuracy of 1 cm.
128	Stepper Motor Interfacing with 8051 Microcontroller: The main principle of this circuit is to rotate the stepper motor step wise at a particular step angle. The ULN2003 IC is used to drive the stepper motor as the controller cannot provide current required by the motor.
129	Frequency Counter Circuit: Here we design a simple frequency counter system using two timers and two counters. While one of the Timer IC is used to produce clock signals, the other is used to produce the time limited signal of one second.
130	Interfacing 7 Segment Display to 8051: This article describes you how to interface seven segments to AT89C51 microcontroller. This system displays the digits from 0 to 9 continuously with a predefined delay.
131	LC Meter using 555 Timer: This is a simple LC Meter circuit designed using 555 Timer and 8051 microcontroller. It is mainly used to measure value of a reactive element like a capacitor or an inductor.
132	TV Transmitter Circuit: The main principle of this circuit is to transmit the audio and video signals. Here audio signals are frequency modulated and video signals are PAL modulated. These modulated signals are applied for the antenna.
133	DC Motor Interfacing with 8051 Microcontroller: Here is a simple but very useful circuit in our real life named interfacing DC motor with 8051 microcontroller. It describes you how to control the DC motor using AT89C51 controller.
134	Stun Gun Circuit: This Stun gun circuit is mostly used as a weapon to stun or send shock waves to the target with the intention to weaken or paralyze it.
135	Transistor Intercom Circuit: This transistor intercom circuit is a simple two way intercom circuit which is used for the dual purpose of sending as well as receiving signals.
136	LED Interfacing with 8051: The main principle of this circuit is to interface LEDs to the 8051 family micro controller. Commonly, used LEDs will have voltage drop of 1.7v and current of 10mA to glow at full intensity. This is applied through the output pin of the microcontroller.
137	Wailing Siren Circuit: The main principle of this circuit is to produce a wailing siren. The 555 timer IC is operated in astable mode. When the switch is pressed, speaker produces high pitch siren and when it is released, its pitch decreases and is switched off after 30 seconds.
138	Audio Tone Control Circuit: This article explains you how to design an audio tone control circuit with the gain of around 25. This design needs less number of components and it is cost effective.
139	FM Remote Encoder/Decoder Circuit: This is a simple post which shows you how to design FM remote encoder and decoder circuit using RF600E and RF600D ICs. This pair of encoder and decoder ICs establishes the communication with high level security. The operating voltage of these ICs is from 2V to 6.6V DC.
140	Wireless Mobile Battery Charger Circuit: This circuit mainly works on the principle of mutual inductance. This circuit may be used as wireless power transfer circuit, wireless mobile charger circuit, wireless battery charger circuit, etc.
141	Battery Level Indicator: This article explains you how design battery level indicator. You can use this circuit to check car battery or inverter. So by using this circuit, we can increase the lifetime of battery.
142	FM Radio Circuit: FM Radio circuit is the simple circuit that can be tuned to the required frequency locally. This article describes the circuit of FM radio circuit. This is a pocket sized radio circuit.
143	LED Lamp Circuit using USB Port: This is a simple USB LED Light circuit which produces an output of 5v. It may be used as emergency light and also as a reading lamp.
144	Interfacing GPS with 8051 Microcontroller: In this interfacing of GPS with 8051 circuit, GPS module calculates the position by reading the signals that are transmitted by satellites.
145	How to Interface Real Time Clock with PIC18F: Get an idea about RTC, PIC Microcontroller pin diagram and how to interface RTC with PIC18F. RTC is an integrated circuit which keeps track of current time.
146	Random Number Generator using 8051: This circuit helps to generate a random number in between 0 to 100 when push button is pressed and it may be used in the games like monopoly, snake ladder.
147	Active Audio Crossover Circuit: Audio crossover is an electronic filter used in audio applications to send the appropriate signal to the speakers or drivers. This circuit is used in HiFi audio systems to separate the frequency bands from audio signal.
148	IR Audio Link Circuit: This simple IR audio link circuit is used to transmit audio signals wirelessly. This IR audio link is able transmit audio signals up to 4 meters.
149	Cellphone Controlled Home Appliances: This mobile controlled home automation system is designed without using microcontroller. We can also control a robot using this technology by making some modifications.
150	Variable Voltage Power Supply: This helps to design a variable power supply circuit which will provide 0 to 28V at 6 to 8 amps. It can be used in various power amplifiers and oscillators to provide DC supply.
151	Digital Clock using 8051: This circuit displays the time on LCD. For this clock, we can set the time at any instant. Here the clock works in 24 hour mode and the RTC chip is configured by programming 8051 controller.
152	GSM Interfacing with 8051: The main principle of this circuit is to interface a GSM modem with the microcontroller. The microcontroller used is AT89C51 microcontroller.
153	Multi Channel Audio Mixer Circuit: This audio mixing circuit has 2 MIC inputs and 2 line inputs. If you want to increase the input channels according to the application then add same circuit in parallel with the existing circuit.
154	Puff to OFF LED Circuit: The main principle of the circuit is to turn off the LED by a puff. The puff applied to the mic is converted into a voltage whose value is very small. This voltage is amplified and applied to the circuit in order to make the led turn off.
155	Biometric Attendance System: The main aim of this circuit is to take the attendance using biometric method and display when requested. This can be used in educational institutions, industries, etc.
156	Light Activated Alarm Circuit: The main principle of this circuit is to produce sound depending on the light intensity falling on the circuit. As the light intensity falling on the circuit increases, it produces pulses with more duration and thus producing more sound. The main part of the circuit is 555 timer IC.
157	Electronic Eye Controlled Security System: This is a simple electronic eye controlled security system circuit designed using 7805 voltage regulator and LDR. It is used in security applications.
158	USB Sound Card Circuit: This USB sound card circuit is a device which allows an embedded system to create and record real and high quality sound. Read this post for more details.
159	10 LED VU Meter Circuit: VU Meters are used in many applications like discotheques to measure the level of audio signals. Here is the circuit diagram and working of LED VU Meter.
160	Hi-Fi Dx Bass Circuit: This Hi-Fi Dx Bass Circuit describes the design, principle and operation of a two stage bass boosting circuit using simple high and low pass filters.
161	Wireless Electronic Notice Board using GSM: This wireless electronic notice board using GSM Technology and microcontroller circuit is used to display the data on LCD whatever we sent from the mobile.
162	Working of light dependent resistor
163	Wireless Remote to Control 255 Different Appliances Individually
164	Wireless motor control through RF
165	Wireless message Communication Between Two Computers
166	Wireless Electronic Notice Board Using GSM
167	Wireless Control Of Robotic Arm
168	Wireless Audio Transmitter for TV
169	Water Tank Overflow Alarm
170	Water Sensor Circuit
171	War Field Spying Robot with Night Vision Wireless Camera
172	Voltage Doubler Circuit Using IC 4049
173	Voltage boost by using a resistor with 78XX
174	Voice Controlled WheelChair
175	Visually Camouflaged Vehicles for Military Purposes
176	Visual Monitoring and Alerting System for Restricted Areas
177	Vision Operated Home Automation For the Physically Disabled
178	Video Activated Relay to Control the Load
179	Vibration Alert System for the Deaf
180	Velocity Detector Using Ultrasonic Means
181	Vehicle Indicator
182	Variable power supply and charger with emergency light
183	Using TV Remote as a Cordless Mouse for the Computer
184	User Defined String Display and Marquee Scrolling using LED Array
185	UPFC Unified Power Factor Control
186	Unique Office Communication System Using RF
187	Understanding Decade Counter CD4017
188	Underground Cable Fault Distance Locator
189	UM3561 IC Based Security Alarm
190	Ultra Fast Acting Electronic Circuit Breaker
191	Turn ON at Night Light Controller with Single Sensor Ambiguity Elimination
192	Tsunami Detection and Social Broadcast System
193	Transistor based Security Alarm
194	Transistor Based Secret Bell
195	Transistor as audio amplifier
196	Transformerless Low Loss DC Converter
197	Touch Screen Based Remote Controlled Robotic Vehicle for Stores Management
198	Touch Screen Based Industrial Load Switching
199	Touch Screen Based Home Automation System
200	Touch Controlled Load Switch
201	Tone generator Circuit Diagram
202	Toggle switch using CD4017
203	Toggle flip flop using CD4013
204	Timer Circuit using IC CD 4060
205	Timer Circuit using IC 4026
206	Timer Based Code Lock
207	Timed Switch With User Defined ON and OFF Intervals
208	Time Delay Based Relay Operated Load
209	Thyristor Power Control by IR Remote
210	Thyristor Controlled Power for Induction Motor
211	Thumb Sized Adjustable Voltage Step Up Circuit
212	Three Phase Solid State Relay with ZVS
213	Three Phase Fault Analysis with Auto Reset on Temporary Fault and Permanent Trip Otherwise
214	Thermistor Based Temperature Control
215	Theft Intimation of Vehicle Over SMS to Owner Who Can Stop the Engine Remotely
216	Text to Speech Conversion For Indian Languages
217	Temperature Broadcaster to Twitter Using Arduino Ethernet Interface
218	Tampered Energy Meter Information Conveyed to Concerned Authority by Wireless Communication
219	Synchronized Traffic Signals at Various Junctions Using PIC Microcontroller
220	SVPWM Space Vector Pulse Width Modulation
221	Suitcase Security Alarm
222	Step Up 6 Volt DC to 10 Volt DC Using 555 Timer
223	Stamp Value Calculator for Postage Needs
224	Staircase Light That Turns ON and OFF Automatically When Required
225	Spell Effect Sign Display Circuit
226	Speed Synchronization of Multiple Motors in Industries
227	Speed Checker to Detect Rash Driving on Highways
228	Sound Operated Switch
229	Sound Operated LED
230	Sound Generation using 555
231	Sound generation in audio range
232	Solar Powered LED Street Light with Auto Intensity Control
233	Solar Powered Auto irrigation System
234	Solar Power Charge Controller
235	Solar mobile phone charger circuit
236	Solar Energy Measurement System
237	Smooth Start of a Single Phase Induction Motor
238	Sleep Sensing and Alerting System for Drivers
239	Single Wheeled Self Balancing Bot
240	Single switch motor on/off.. Clockwise/anticlockwise
241	Sine Pulse Width Modulation (SPWM)
242	Simple AC to DC converter using bridge rectifier
243	Short Range Ultrasonic Radar With Distance Measuring Capabilities
244	Shadow Counter Solar Powered Long Range Communication System using Microwave Devices
245	Shadow Alarm using LDR
246	Self Switching Power Supply
247	Seismic sensor
248	Security System With User Changeable Password
249	Security System Using Smartcard Technology
250	Security Alarm for Doors, Almirah, cupboards using Opam
251	Secure room access system
252	Secret Code Enabled Secure Communication Using RF Technology
253	SCADA (Supervisory Control & Data Acquisition) for Remote Industrial Plant
254	Safety Alarm Circuit
255	RFID security access control system
256	RFID Based Passport Details
257	RFID Based Paid Car Parking
258	RFID Based Door Access Control
259	RFID Based Device Control and Authentication Using PIC Microcontroller
260	RF Electrically Directional Antenna Based Tracking System
261	RF Controlled Robotic Vehicle With Laser Beam Arrangement
262	RF Controlled Hovercraft
263	RF based Wireless Remote Control
264	RF based Intruder Alarm
265	RF Based Home Automation System
266	RF based Fire Alarm (Overheat Alarm)
267	Remote Tester Circuit
268	Remote Controlled Toy Car
269	Remote Control For Home Appliances
270	Reminder Alarm
271	Relay operation using Darlington Pair
272	Relay control through mic
273	Relay control by sound
274	Relay activation using TSOP 1738
275	Refrigerator Door Alarm
276	Raspberry Based Home Automation
277	Random Number Generator Using 7 Segment Display
278	Railway Track Security System
279	Railway Level Crossing Gate Control through SMS by the Station Master or the Driver
280	Quadracopter with Video transmission Ability
281	Quadracopter with Six Degrees of Freedom and Obstacle Avoidance Built in
282	Pulse Counter Fed with Infrared Pulses
283	Programmable Switching Control for Industrial Automation in Repetitive Nature of Work
284	Programmable Load Shedding Time Management for Utility Department
285	Programmable Energy Meter for Electrical Load Survey
286	Programmable AC Power Control
287	Pre-programmed Digital Scrolling Message System
288	Predefined Speed Control of BLDC Motor
289	Precision Current Source With Keypad interface to Select the current
290	Precise Illumination Control of Lamp
291	Precise Digital Temperature Control
292	Pre Stampede Monitoring and Alarm System
293	Pre Set Off Timer
294	Power failure alarm
295	Post Encryption Data Scrambling For Maximum Data Security random order
296	Portable Programmable Medication Reminder
297	Porch Light (Auto Turn Off Light) Circuit Diagram
298	Pocket CRO using Android
299	Pin-Pong Ball Board for Eye Catching Marketing
300	Piezo sensor as output
301	Piezo sensor as input
302	Pick N Place with Soft Catching Gripper
303	Phase Sequence Checker for Three Phase Supply
304	Phase Preserving Image Denoising for Maximum Noise Removal
305	Periodically Turning On & Off Mosquito Repellent Circuit Diagram
306	PC Temperature Controller
307	PC Controlled Scrolling Message Display for Notice Board
308	PC Based Wireless Appliance Control
309	PC Based Electrical Load Control
310	Password Based Circuit Breaker
311	Parked Vehicle Indicator
312	Parallel Telephone Lines with Security System
313	Parallel Port Based Home Automation on Linux
314	Panic Sensing and Spontaneous Stabilization System for Cars to avoid Accidents
315	Overheat/Overcooling circuit breaker
316	Over Voltage or Under Voltage Tripping Mechanism
317	Optimum Energy Management System
318	Opamp as comparator
319	Obstacle Avoidance Robotic Vehicle
320	Object Detection by Ultrasonic Means
321	Object Counter with 7 Segment Display
322	Number Guessing Game
323	Notepad Lamp
324	Non inverting amplifier
325	Night Lamp with Timer for Stairs
326	Networking of Multiple Microcontrollers
327	Negative supply using 555 IC
328	NE 555 Timer based Automatic Headlight
329	Music (Data) transfer by IR
330	Multi-Utility Flashing Light
331	Multitone Generator Circuit
332	Multipurpose Timer With Musical Alarm
333	Multimeter Using Android Smartphone
334	Multi Color Lighting
335	Movement Sensed Automatic Door Opening System
336	Motion Detector
337	Mobile Phone Sniffer With Over 10 Meter Range Using An Ultrasonic Device as Antenna
338	Minimizing Penalty in Industrial Power Consumption by Engaging APFC Unit
339	Miniature Photonic Rat Bot
340	Miniature Disguised Location Transmitter for Military Spying
341	Military Grade Video based Steganography
342	Microscope Using A Smartphone
343	Metal Detector Robotic Vehicle
344	MATLAB based Landscape Surveillance System
345	Magic Eye using 555 Timer IC
346	Magic Eye Circuit Using 4049 IC
347	Low pass filter
348	Low Cost Touch Screen For Instant Drawing And Presentations
349	Long range IR
350	Long Range FM Transmitter with Audio Modulation
351	Location Mapping Ariel Vehicle
352	Location Mapping and Routing System for the Blind With GPS Support
353	Location Broadcaster Using Arduino Ethernet Interface
354	Liquid level Alarm
355	Lighting Controller Counts How Many People are in a Room
356	Light sensor using photodiode
357	Light detector
358	Light dependent frequency variation using LDR
359	Life Cycle Testing of Electrical Loads by Down Counter
360	LED Lamp Using CA3140 IC
361	LED Based Pendulum Circuit
362	LDR Based Automatic Lamp
363	Lamp Life Extender by ZVS (Zero Voltage Switching)
364	IR Obstacle Detection to Actuate Load
365	IR Controlled Robotic Vehicle
366	Invisible Image Watermarking in Python
367	Inverting amplifier with signal feedback
368	Inverting amplifier using 741
369	Interfacing 4026 with 7 segment display
370	Intelligent Bot Network for Area Monitoring and reporting
371	Integrated Energy Management System Based on GSM Protocol with Acknowledge
372	Infrared (IR) sensor
373	Industrial Temperature Controller
374	Industrial Power Control by Integral Cycle Switching without Generating Harmonics
375	Industrial Battery Charger by Thyristor Firing Angle Control
376	Induction Motor Protection System
377	Incoming Phone Ring Light Flasher
378	Image Watermarking Using Python
379	IC555 based Multicolor LED Lamp Circuit Diagram
380	IC 555 Based Message Display Circuit
381	Humidity Detector Circuit
382	Home Automation Using Digital Control
383	Hit the Target Game
384	High Voltage DC Upto 2kv from AC by Using Diode and Capacitors in Voltage Multiplier Circuit
385	High Voltage DC by Marx Generator Principles
386	Hidden Active Cell Phone Detector
387	H-bridge using transistor
388	Hardware Level Bit tracing and Data Interpolating Forensic System
389	Hardware Authentication Dongle with Fingerprint Recognition
390	GSM Based Monthly Energy Meter Billing via SMS
391	GSM Based Energy Meter Reading with Load Control
392	GPS enabled Quadracopter
393	Gesture Operated Wheel Chair
394	Generating time delay with 555 IC
395	Full range centigrade temperature sensor
396	Frequency Counter Using Smartphone
397	Four Quadrant DC Motor Speed Control with Microcontroller
398	Four Quadrant DC Motor Control without Microcontroller
399	Flip Flop based Staircase Switch
400	Flash Memory with Self Destroy Master Lock
401	Flash Flood Intimation Over GSM Network
402	Fixed voltage power supply
403	Fire Powered Mini Portable Power Supply
404	Fire Fighting Robotic Vehicle
405	Finger Print Based Security System
406	Fastest Finger Press Quiz Buzzer
407	FACTs by SVC (flexible ac transmission)
408	FACTs (flexible ac transmission) by TSR
409	Facebook Connected Arduino And Intelligent Event Reporting
410	Fabrics That Generate Energy using Dye Based Solar Cells
411	Electronic Timer Circuit
412	Electronic Thermometer for Beverage Temperature Measurement
413	Electronic Soft Start for 3 Phase Induction Motor
414	Electronic Number Game
415	Electronic Notepad
416	Electronic Nose to Indicate gas Leakage in Underground Mines and Industries
417	Electronic Eye Controlled Security System
418	Electronic Dog to Sense The Proximity of a Specific Purpose
419	Electronic Code Locking System
420	Electronic alarm for cash box, lockers
421	Electromagnetic Climbing Robots for Industries
422	Easy to Use Automatic Light Controller to Turn ON Lights In Dark
423	Dual converter Using Thyristors
424	DTMF Decoder
425	DTMF Based Load Control System
426	DTMF Based Car Lock System
427	DNA Based Mathematical Calculator
428	Distance Measurement by Ultrasonic Sensor
429	Display System used in Restaurant
430	Display of Dialed Telephone Numbers on Seven Segment Displays
431	Dish Positioning Control by IR Remote
432	Discotheque Light Stroboscopic Flasher
433	Differential amplifier
434	Detecting Power Grid Synchronization Failure on Sensing Frequency or Voltage Beyond Acceptable Range
435	Darkness Detector Alarm
436	Cyclo Converter Using Thyristors
437	Continuous Speech to Text Conversion for Indian Languages
438	Continuous Speech Processing Using Python
439	Contactless Liquid Level Controller
440	Comprehensive Threat Detection for Offices
441	Combinatorial Digital Circuit Logic Determining Device
442	Color distinguished using LDR/Color sensor using LDR
443	Coin Toss/Flip Simulator Circuit
444	Closed Loop Control for a Brushless DC Motor to Run at the Exactly Entered Speed
445	Clock with LED pendulum with tick tock sound
446	Cell Phone Operated Land Rover
447	Cell Phone Based DTMF Controlled Garage Door Opening System
448	CD4049 Based LED torch
449	CD4001 IC based Lighting System
450	CD 4060IC based Message Display Circuit
451	CD 4060 Based Security Alarm
452	CD 4027 Based Emergency Lighting System
453	CD 4013 Based Two Way Switch
454	CD 4013 based Sound Sensing Module
455	Car Reverse Horn
456	Camouflaged Voice Recording and Transmitting System
457	Burglar alarm based Home Security System
458	Bluetooth Controlled Robot
459	BLDC Motor Speed Control with RPM Display
460	bidirectional Rotation of an Induction Motor with a Remote Control Device
461	Beacon Flasher Using Microcontroller
462	Bathroom Light Off Timer
463	Background Interpolation for Selective Image Cancellation
464	AVR based Heart Rate Monitoring System With Health level Indicator
465	Automatic Wireless Health Monitoring System in Hospitals for Patients
466	Automatic Wash Basin Tap Controller
467	Automatic Vehicle Image Capturing When Overriding traffic lights
468	Automatic Threshold Detection System for Phase Preserving Image Denoising
469	Automatic Surveillance Camera Panning System from PC
470	Automatic Star Delta Starter Using Relays and Adjustable Electronic Timer for Induction Motor
471	Automatic Speed Regulation Depending On Incoming Vehicle On High Ways (Fuel Injection)
472	Automatic Solar Tracker
473	Automatic solar street light controller
474	Automatic Road Level Detection And Alerting System for Cars
475	Automatic Power OFF timer for CD player
476	Automatic light/dark indicator
477	Automatic Light Lamp with Morning Alarm
478	Automatic Light Beam Shifting Of Vehicles On High Ways
479	Automatic Heat Detector
480	Automatic Fan Speed Regulator
481	Automatic Exhaust Fan Control Coupled To Gas Leak Detection
482	Automatic Elevator Light and Fan Controller
483	Automatic Dialing to Any Telephone Using I2C Protocol on Detecting Burglary
484	Automated Vehicle Identification and Toll-Pass System.
485	Automated Traffic Signal Controller
486	Automated Car Parking System
487	Auto turn off battery charger
488	Auto Selection of Any Available Phase, in 3 Phase Supply System
489	Auto Power Supply Control from 4 Different Sources: Solar, Mains, Generator & Inverter to Ensure No Break Power
490	Auto Metro Train to Shuttle Between Stations
491	Auto charging grinding machine with solar power
492	Auto Braking System For Cars Detecting Momentum and Road Irregularities
493	Audio Amplifier using Opamp
494	ATmega644 JTAG Debugger
495	Ariel Red Herrings to Mislead Missile Tracking Systems
496	Arduino Ethernet Interface for Industrial Automation
497	Arduino Based World Intelligent Event Detection and Alert System with Network Interface
498	Arduino based Waveform Generator For Electronics Laboratory
499	Arduino Based Swarm Bots
500	Arduino Based Online Database Interfacing
501	Arduino Based Earthquake Detection Social Network Broadcast system
502	Anti Theft Alarm for Bikes
503	Android Controlled Wheel Chair for the Physically Handicapped
504	Android Based Waveform Generator
505	Android Based Waveform Analyser
506	Amplifier for Musical ICs
507	AES256 bit Highly Encrypted Image Steganography
508	AES128 Encrypted hardware Lock Using AVR ATMEGA-16
509	Active high trigger for 555 in monostable mode
510	Accident Detection and Avoidance System Using Doppler Radar Interfaced with ATMEGA16
511	A Swarm of Mutually Interacting Metal Detecting Robots For Scanning the Area
512	A Multiple Bots Operated with a Single Base Station
513	90 Second Timer
514	555 Timer As Amplifier
515	4 Player Quiz Buzzer
516	3D Notice Board using LED Cube
517	2 to 4 Amp arduino Based Motor Shield