;----------------------------------------------------------------------------------------
We can provide any EFY project in short time
we can aslo add modifications if required by customer
contact us with project name for details
ph: 9247436405, email projectkits@gmail.com    website: www.liveprojects.page4.me
;----------------------------------------------------------------------------------------
 Sno    Electronics for you do it your self projects    cost       
;----------------------------------------------------------------------------------------
    RFID-based Security System:
This circuit is a security system that uses RF tags as security credentials. It comprises of a microcontroller AT89C52 and an RFID reader.           
    Secure Digital Access System Using iButton:
This is a iBUTTON based secured system that uses a microcontroller. Whenever someone touches the iBUTTON using his own iBUTTON, the firmware inside AVR reads its unique ID and relay operates which in turn opens up the door.           
    Pulse Counter Using AT89C4051:
This is a circuit for a pulse counter that uses a pulse source and a microcontroller-based counter that displays the accumulated count on a LCD module.            
    Wireless Equipment Control Using AT89C51:
The circuit that uses microcontroller AT89C51 can control four devices from a distance of upto 30 metres wirelessly. An LCD module is used to show the device number and preset control time at the transmitter module.        
 
    Remote Controlled 6 Camera CCTV Switcher:
This is a circuit for a remote controlled 6 camera CCTV switcher that uses microcontroller, infrared module and other components to control the operation of 6 CCTV cameras. Controlling messages can be seen on a LCD module.            
    Cellphone-based Device Control With Voice Acknowledgement:
This circuit lets you operate your home appliances such as lights and water pump from your office or any remote location. The system also gives you voice acknowledgement of the appliance's status. It comprises microcontroller AT89C51, DTMF decoder MT8870, voice recording/ playback device APR9600.            
    PIC16F877A Based Temperature Monitoring System:
This circuit here uses a PIC16F877A microcontroller along with a LM35 sensor to measure temperature and displays it on a 16×2 LCD in degree Celsius.         
     Eight Channel Data Aquisition And Logging System:
The AVR based microcontroller system described here aquires analogue data from eight channels and sends it to a PC via UART channel.            
    Frequency Counter:
This is a circuit that uses IC NE555, five decade counters along with a 7-segment driver IC to form a 5 digit decimal counter. The output of the decimal counter is used to drive the numerical display of frequency counter.            
    Microcontroller-based Serial Data Transfer To PC:
This circuit uses a microcontroller AT89S52 to transfer serial data to PC through the RS232 driver.
           
    Solid State Voltage Stabiliser:
This is a circuit for a solid state voltage stabiliser that gives indication of low/ high voltage and gives a stabilised output of 220V. Its works anywhere in the range from 120 V to 280 V.         
;----------------------------------------------------------------------------------------
    MICROCONTROLLER PROJECTS           
;----------------------------------------------------------------------------------------
    AT89C51 based DC motor controller
This is a circuit for an AT89C51-based DC motor controller that can regulate the speed, direction of rotation, and the running mode of motor. It then displays the corresponding messages on an LCD.            
    Microcontroller-Based Speedometer-Cum-Odometer
This is a circuit for a microcontroller-based digital speedometer cum odometer for a motorbike that can display the speed and the distance travelled by a bike.            
    Microcontroller-Based School Timer
This is a circuit for a microcontroller-based school timer that can be programmed for ringing the school bell.            

Infrared Toy Car Motor Controller  
This circuit can switch on or off remote-operated toy cars with the help of a TV/ video remote control handset, operating at 30–40 kHz.
 
Electronic Security System  
This is a circuit for a security system that consists of three zones and a monitoring circuit. Each zone contains a sense switch of its own that sets off an alarm whenever any door is open and an indication is given in the monitoring system with an LED corresponding to the zone.

Remote Control For Home Appliances  
This circuit can be used to turn off electrical appliances by using any remote from a maximum of ten metres distance.
;----------------------------------------------------------------------------------------
 
IR Remote Switch  
This circuit can switch off an electrical appliance using IR receiver from a TV remote from a maximum distance of ten metres.
 
FM Booster  
This is a circuit for a FM booster that amplifies FM signals coming from distant FM stations.
 
Ultra-Bright LED Lamp  
This circuit uses ultra bright white LEDs to create a LED lamp that operates on AC. The LEDs can be used in series of 16 LEDs or two parallel combination of 23 LEDs.
 
Mobile Cellphone Charger  
This is a circuit for a mobile cellphone charger that uses three NiCd cells or eight pencil cells to charge the battery connected at the output terminals.
 
Wireless Switch  
This is a circuit that acts as a wireless switch for home appliances. One needs to move his hand between the infrared led and the phototransistor to interrupt the infrared beam and the appliance starts working through the relay. When the hand is removed from the beam the appliance stops working.
 
Mobile Phone Battery Charger  
This is a circuit for a low cost mobile phone battery charger.
 
Solar Lighting System  
This is a solar lighting system that uses a photovoltaic cell to charge a battery that can be used to light a lamp during night time. A transformer is also connected to charge the battery through AC.
 
Invisible Broken Wire Detector  
This is a circuit for a broken wire detector that consists of an LED that blinks in the presence of AC mains voltage. The probe is moved over the wire to detect the breaking point. When the point is reached where the wire is broken, the LED stops blinking.
 
Remote-Controlled Fan Regulator  
This circuit uses can control a fan's speed remotely by using an infra red receiver module with the help of a TV remote.
 
Quality FM Transmitter  
This circuit can transmit FM signals upto a distance of 500 metres with a power of 200 mW. It uses a 9 V battery.
 
Laser Torch-Based Voice Transmitter And Receiver  
This circuit uses laser and phototransistor to make a communication module that is based on laser.
 
Automated Traffic Signal Controller  
This is a circuit for an automated traffic signal controller that uses GAL device and programming to implement a traffic light controller system.
 
Laptop Protector  
This is a laptop protection unit circuit that uses a homemade tilt switch. The switch activates the alarm whenever the laptop case is tilted.
 
Mini UPS System  
This circuit provides an uninterrupted power supply (UPS) to operate 12V, 9V and 5V DC-powered instruments at upto 1A current.
 
Ding Dong Bell  
This circuit implements a door bell using IC 8012-2.
 
Infrared Cordless Headphone  
This is circuit for a infrared cordless headphone that has transmitter and receiver modules. It can provide a range of 6 metres without using lens and reflectors.
 
Hit Switch  
This is a circuit for a hit switch that uses a piezoelectric diaphragm to work as a switch for electrical appliances. One hit on the diaphragm switches on the appliance and another hit turns it off.

Security System Switcher    (New)
This is a circuit for a security system that can detect movement of any intruder through a transducer and activate any security device through a relay.

Four-Stage FM Transmitter    (New)
This circuit is a four stage FM transmitter that can be used to transmit FM signals within a range of 88 MHz -108 MHz.

Versatile Probe   
This is a circuit for a versatile probe that can perform continuity testing, identification of the type of the transistor and transformer windings.

Numeric Water-level Indicator   
This is a circuit for water level indicator which displays water level in numeric form from '0' to '9', with '0' for empty and '9' for full.

Telephone Call Recorder   
This is a circuit that can be used along with a computer to record calls to a telephone. The telephone can be connected to the circuit, which in turn, can be connected to the computer. A software such as Audacity Audio Recorder records the call.

Pyroelectric Fire Alarm   
This circuit for a fire alarm has a piezo sensor that detects the temperature in the room. It sets off an alarm if the temperature increases by more than 10 C. Then, a solenoid pump connected to the circuit starts operating which can be used to spray foam or water on fire.

Duophone   
This is a circuit to access two telephone lines through one telephone set. The conversations will remain independent on both lines unless they are combined with the conference switch on the circuit.

Smart Hearing Aid   
This circuit saves battery power in a hearing aid circuit by switching on the sound amplifier section in the circuit only when a sound is detected.

Triple Power Supply   
It is a circuit for triple power supply that can be used in laboratories or by hobbyists. It gives the option for three power supplies. One for variable voltage,one for +12 V and +5 volt and one for -12 V and -5 V.

Automated Alarm Circuits   
This is a circuit for an automated alarm system that consists of a control unit and a sound alarm section. There are two sound alarm circuits here that produce bird-chirping sound and British police siren sound respectively. Any of the sound alarm sections can be used along with the control unit to make an alarm circuit with desired alarm sound.

Night Alert   
This is a circuit that senses a dog's barking sound and then turns on a lamp for about two minutes.

Traffic Controller   
This is a circuit for a traffic controller that uses three 15 W bulbs as the red, amber and green lights. It can also be used to teach traffic rules to children.

Three-Phase Appliance Protector   
This circuit protects three-phase appliances from failure of any of the phases. It disconnects the power supply through the contactor and automatically restores the three-phase supply to the appliance after a time delay when all the phases are available.

Bicycle Indicator   
This is a circuit for a bicycle signalling unit that can be used as a bicycle indicator. It contains two set of LEDs, one set for showing the right turn of bicycle and the other for left turn. It also has an emergency mode in which both the left and right indicators starts working simultaneously. It also has steady glow LEDs that indicate the working mode of the circuit.

Aquarium Probe   
This circuit of aquatic probe contains a signal diode that is used to monitor the temperature of water and indicate the rise in temperature through audio-visual indicators.

Poor Man’s Hearing Aid   
This is a low cost hearing aid circuit. Its sensitivity is less than that of commercial hearing aids. The circuit has two cascaded LA4537M ICs that give it fair sensitivity and reception range.

Glow Plug Controller   
Glow plugs are used to heat the air inside a diesel engine so that the engine starts quickly. The Glow Plug Controller circuit heats the air inside the engine for about 25 seconds. When the circuit is started, a red LED glows to indicate the heating process. After a while green LED glows, followed a short beep of buzzer to indicate the engine is ready for starting.

Drinking Water alarm   
This is a circuit for water alarm unit that can produce an alarm sound in the loudspeaker when water starts flowing through the tap. It uses a self made water sensor connected to 555 to detect the flow of water. Then a signal is sent to loudspeaker when water starts flowing in the tap which starts the alarm.

Mobile Bug   
This is a circuit for a mobile transmission detector which can detect use of a mobile phone within the range of 1.5 metres. Whenever usage of mobile phone is detected such as calling or texting a beep alarm starts sounding and a led blinks.

Automatic Low-Power Emergency Light   
This is a circuit for an emergency light that uses white LEDs for illumination. It consists of a charging circuit that charges the battery when main supply is on and automatically stops charging when battery is fully charged. It turns on automatically when main supply fails and turns off when main supply is back.

Door Knock Alarm With Timer   
This low-cost circuit sounds an alarm when there someone knocks on the door. It consists of a piezoelectric element plate fixed at the centre of the door wing by using cellotape.

Dual Supply From Single Battery Source   
This circuit provides both +9V as well as -9V supply from a single 9V battery. It consists of timer 555 IC, negative-voltage regulator IC and a few discrete components.

Variable Timer with Music   
This simple timer can be set to run for different time settings ranging from 30 seconds to 4.5 minutes. Also, a musical note is played at the end of the set time.

Strip LED Lamp   
This circuit uses strip LEDs to make an automatic white LED lighting source.

Home Appliance Control Using TV Remote   
This circuit is designed to switch on/off any home or industrial appliance by using the TV/DVD remote controller. The circuit can be operated up to a distance of 5-10 metres depending on the remote used.

CCFL Tester for LCD Screens   
This is a circuit to test the CCFL (Compact cold cathode fluorescent lamp) tube in a LCD backlight unit, which may help the hardware technician to speed up his work. This basic circuit (go/no go test) is portable, 6V battery operated and can be used to test almost all types of LCD backlight CCFL tubes.

Remote Control for Toy Car   
Make any battery-operated toy car remote-controlled using this circuit. The circuit, consisting of an infrared transmitter-receiver pair, uses IR beam transmission to switch the toy car 'on' or 'off '.

Laser Communication System   
This laser communication system transmits sound or music signals through a laser beam. It consists of a laser diode transmitter and a solar panel receiver.

Telephone Line In-Use Indicator   
This circuit gives a visual indication of whether a telephone line is in use or not, helping two or more people sharing the line to avoid interrupting each other's calls. As the circuit connects in parallel with the telephone line, it can also detect phone tapping/misuse attempts.


Wireless Extender for IR Remote Controls   
Using this system, you can control your IR remote-controlled home appliances like DVD player and air-conditioner from another room without the hassle of running extra cables between the two rooms. The system wirelessly sends infrared signals from one room to another.


Laser-based Intruder Alarm   
This alarm circuit can be used to warn against trespass or unauthorised access in your premises. Its range can be extended further to protect the perimeter of a building from intrusion by using a cascade arrangement of multiple alarms.

 
AC Mains Bistable Switch   
This AC mains-operated bistable switch turns on or turns off a device using a miniature neon lamp and a few discrete components. This switch can be used for control panels, appliances and lighting controls.

Gas Leakage Alarm   
This is a circuit that detects the leakage of LPG gas and alerts the user through audio-visual indications.

Transistorised Code Lock With Torch   
This electronic lock for domestic use opens only when you connect the right combination of five switches. There are twelve switches in total. If you connect a wrong combination, the lock remains closed. At night, flip a switch on to enable the torch.

Call Bell with Welcome Indication   
This is a simple call bell circuit that displays a welcome message when somebody presses the call bell switch momentarily. The alphanumeric display can be fitted near the call bell switch.

Dew-Point Sensor   

Cash Box Guard   
It is a security circuit that can activate an emergency beeper in case of theft. It can also be used to trigger any external burglar alarm unit.

Infrared Illuminator   
It is an circuit which can generate wavelengths in the infrared region of the spectrum. It can be used with security cameras to design a security system which can throw infrared light which is not visible to human eye so as to capture movements in dark.

PC Temperature Alarm   
This circuit uses a temperature sensor to detect the temperature inside the PC and generates an alarm if the temperature exceeds a pre-set limit.

Smart Laptop Docking Station   
This circuit is used to convert an ordinary docking station into a smart electronic laptop docking station equipped with anti theft alarm. It features an optosensor. When someone tries to remove the laptop from the docking station the alarm will beep and an LED will glow.

Mobile Car Stereo Player   
This is a circuit that enables users to design a car stereo player that takes its input from the 3.5 mm audio jack of a mobile phone.

Electric Guitar Preamplifier   
This is a circuit for a guitar preamplifier that can capture mechanical vibrations (any standard guitar pickup) and then convert them into an electrical signal. The signal is then amplified by an audio amplifier.

Clap Switch   
This is a circuit for a clap switch that allows control of a device by clapping twice within three seconds.

Digital Thermometer   
It is a circuit for a digital thermometer that can measure temperatures upto 150 degree C with an accuracy of ±1 degree C.

Ramp Controlled Light   
The circuit described here can light a lamp from zero intensity to maximum intensity in a specified time set by user. The brightness is controlled by a continuously running ramp voltage generated by timer 555.

Economical Pump Controller   
This is a circuit for an low cost pump controller which automates the filling of water in a tank. When the water level falls below a certain low point, the circuit switches on the pump which remains on till the water level reaches a high point. The low and high points are pre-set by the user.

UPS for Cordless Telephones   
This is a circuit that acts as a UPS for cordless phones so that they can work even in case of a power failure. When the supply is on the circuit charges the battery of UPS and in case of power failure the circuit supplies power to cordless phone from battery.

Watch-dog for Telephones   
This is a circuit for a security device for telephone that transmits a loud tone over the telephone lines in case of misuse and sounds an alarm.

Automatic Temperature Controlled Fan   
This is a circuit that can linearly control the speed of a fan depending on the temperature of the room.

Sensitive Temperature Switch   
This is a circuit for a highly sensitive temperature switch that sets off an alarm whenever there is a sharp rise in the temperature.

Digital Dice With Numeric Display   
This is a circuit for a digital dice with numeric display that generates random numbers from 1 to 6 and displays them on a 7-segment LCD. The circuit can be modified to increase the range from 1 to 9.

Magic Lights   
This is a circuit that employs 14 bicolour LEDs to produce dancing patterns.

Accurate Electronic Stop Watch   
This is a circuit for a electronic stop watch that can count up to 100 seconds with a resolution of 0.01 seconds or up to 1000 seconds with a resolution of 0.1 seconds.

Fluid Level Detector   
This is a circuit for a simple fluid level detector.

Intelligent Switch   
This is a circuit for an intelligent switch that uses a photo transistor to detect day or night time and switches on an emergency light when it is dark in case of power failure.

Low Current High Voltage Power Supply   
This is a circuit for a low current high voltage power supply that can provide high output voltage. It has been implemented by using a combination of silicon diodes and zener diode.

Running Message Display   
This is a circuit that can display a running message on a LED arrangement by using a Johnson decade counter.

Color Sensor   
This is a circuit for a color sensor which uses three LDRs to detect the color of object placed in front of it and indicates the same by glowing a corresponding color LED among 8 LEDs.

Handy Zener Diode Tester   
This circuit can test zener diodes with a breakdown voltage up to 120 volts. It takes only 6 volts as power supply and consumes less than 8 mA current.

Automatic Room Power Controller   
This is a circuit for an automatic room power controller that consists of two LDRs. The LDRs sense the arrival of a person into the room and switch on the lights. It is an intelligent circuit that takes feedback from both LDRs to sense the persons coming inside the room.

Telecom Headset   
This is a circuit for a low cost headphone for a telephone that includes a visual ringer circuit. It has a condenser microphone as voice transmitter.

Smart Phone Light   
This is a circuit for a smart phone light that uses a LDR that judges whether its day or night. If LDR detects night then a lamp is switched on when the telephone rings. The circuit takes power from the telephone line itself.

Clap Remote   
This is a circuit that can control up to four switches through clapping twice. The first clap takes the system out of standby mode while the second clap turns on or off the corresponding switch.

CD-Rom Drive as Digital-Audio CD Player   
This circuit converts CD ROM drive in computers into a standalone audio CD player by just connecting power supply options to CD ROM and interconnecting it to either a tape deck or an audio amplifier.

Automatic Dual Output Display   
This circuit lights up ten bulbs sequentially, first in a direction from first bulb to last bulb and then in a reverse direction.

Miniature Strobe Light   
It is a circuit for a strobe light that uses a neon glow lamp with reflector to create an effect of a strobe light.

Frequency Measurement Using PC   
This circuit uses parallel port of a computer for data input from binary counters. This data is used for measuring time and calculating the frequency of the signal.

40-Meter Direct Conversion Receiver   
This is a circuit of direct-conversion receiver that can be used to listen to amateur radio QSO signals in CW as well as in SSB mode in the 40-metre band.

Digital Switching System   
This is a circuit for a digital switching system that can be used to control 16 devices with the help of two push to on switches. A master counter is used to select any of the device and an LED indicates the selected device.

Electronic Scoring Game   
This is a circuit for a electronic game based on random number generation through a counter.

Ultra Low Drop Linear Regulator   
This is a circuit for a MOSFET based linear voltage regulator that can regulate ultra low voltage drops as low as 60 mV at 1 ampere.

Simple Analog To Digital Converter   
This is a circuit for a simple analog to digital converter that uses a AD0808 to convert analog signals into digital format.

Magnetic Proximity Switch   
This circuit can detect magnetic fields nearby through a reed switch. Whenever a magnetic field is detected, reed switch gets closed and a relay is energised in the circuit that can be used for various purposes.

Sleep Switch Cum Wake Timer   
This circuit can be used either as a sleep switch or as a wake timer. It provides a dual display for showing units and tens places of time in minutes or seconds format.

Cordless Phone Backup   
This is a circuit for a cordless phone backup unit that can be used to provide power supply to cordless phone at the time of main supply failure. A green LED indicates the presence of main supply and the circuit charges a rechargeable battery and puts the supply to cordless on battery in case of power failure.

Low Cost Transistorised Intercom   
This is a circuit for a low cost intercom that is made by using transistors.

Teleremote Control   
This is a circuit that can be used to switch on and off electrical appliances through a telephone line.

Electrical Equipment Control Using PC   
This is a circuit that uses the printer port of a PC to interface it with a circuit and then by using the software provided electrical appliances can be controlled.

Self Switch Power Supply   
This is a circuit for a self switch power supply that can provide voltage in the range of 3.7 V to 8.7 V and turns itself off when no load is connected to it.

Long-range FM Transmitter   
This is a circuit for a FM transmitter that can provide a range up to 2 kms for transmission.

Simple Code Lock   
This is a circuit for a simple electronic code lock that uses IC CD4017 to implement locking. This circuit supports 9 digit lock codes.

Protection for your Electrical Appliance   
This circuit saves electrical appliances from damage in case of sudden tripping and resumption of power supply. It does so by switching off the main supply to the load which can only be resumed manually. The circuit does not work in the case of power fluctuations of the order of 1 millisecond to 5 milliseconds due to use of a large value capacitor.

Telephone Call Meter Using Calculator and COB   
This is a circuit for a telephone call meter designed with a calculator and chip on board. The calculator enables conversion of STD/ISD calls to local call equivalents and always displays current local call-meter reading.

Phone Broadcaster   
This is a circuit for a phone broadcaster that transmits telephone conversation over a telephone line by converting it into a FM signal.

Precision Digital AC Power Controller   
This is a circuit for a digital AC power controller that can set different firing times corresponding to different power angles.

Parallel Telephone With Secrecy   
This is a circuit that maintains secrecy of a telephone in a parallel telephone line where two telephones are connected to a same line by using a DPDT toggle switch so that the conversation can be active on only one line at a moment.

Power Supply Failure Alarm   
This is a circuit for a power supply failure alarm. It requires no separate supply for itself. It uses a capacitor to store enough charge for the alarm to sound for about one minute in case of a power failure.

Telephone Line Based Audio Muting and Light on Circuit   
This circuit mutes television audio/ music system when a telephone ring arrives and lights up a bulb to indicate the telephone ring.

Low Cost PCO Billing Meter   
This is a circuit for a low cost PCO billing meter that counts the number of pulses during a certain call and displays the corresponding number of rupees charged on a calculator according to a pre defined pulse rate by user.

2-Line Intercom-Cum-Telephone Line Changeover Circuit   
This is a circuit for telephone intercom cum line changeover circuit that can be used to connect two telephones in parallel and also as a 2 line intercom using switches and a ring tone sensing circuit.

Telephone Ringer Using Timer ICs   
This circuit can produce ringing tones similar to those produced by a telephone for use in intercom operations.

Automatic Speed Controller For Fans and Coolers   
This is a circuit for an automatic speed controller for fans and coolers that can regulate speed of a fan during operation automatically. The fan is run at full speed for a predetermined time. The speed is decreased to medium after some time, and to slow later on. After a period of about eight hours, the fan/ cooler is switched off.

Precision Attenuater with Digital Control   
This is a circuit for a low cost precision attenuator with digital control.

Precision Amplifier with Digital Control   
This is a circuit for a precision amplifier with digital control that can provide a gain upto 100.

Digital Mains Voltage Indicator   
This is a circuit for a digital mains voltage indicator that displays main voltage in the form of a LED bar graph with 16 LEDs. The first LED indicates voltage level at 50 V and the 16th LED shows voltage level for 280 V.

A Hierarchical Priority Encoder   
This is a circuit for a priority encoder that encodes the highest and the second highest priority information of an 8 line incoming data.

Darkroom Timer   
This is a circuit for darkroom timer that can produce musical tones after an interval of one second.

Shortwave Transmitter   
This is a circuit for a shortwave transmitter that can operate in the range of short wave HF band (6 MHz to 15 MHz).

Auto Reset Over/Under Voltage Cut-Out   
This is a circuit that automates relay operation for electrical appliances and cuts off the power supply whenever the voltage varies outside the voltage range of 160 V to 270 V.

Electronic Dice Using AT89C2051   
It is a circuit that implements an electronics dice using the random number generation capabilities of an AT89C2051 microcontroller. A random LED lights up in the panel of seven LEDs.

Weekly Reminder   
This circuit reminds you of all the important tasks that are due on a specific day every week. It can flash an LED on a particular day of week. It also has a buzzer that can be turned on manually through a switch, if beeping is required along with flashing for reminder.

Long Range IR Transmitter   
This is a circuit for a long range IR transmitter that uses three IR LEDs in series to increase the power of IR signal generated.

Versatile CMOS TTL Logic and Clock Probe   
This is a circuit for a logic probe that can test CMOS and TTL logic circuit and indicate their status by using combinations of red, green, yellow LEDs and a buzzer.

Automatic Emergency Light   
This circuit implements the concept of emergency light through relays. The circuit lights up LEDs in case of power failure and charges the batteries otherwise.

Telephone Conversation Recorder   
This is a circuit for a telephone conversation recorder that can record conversations over the telephone in a tape recorder.

Programmable Door-Bell with Flashing LEDS   
This is a circuit for a programmable door bell that contains five orange and five green LEDs.

Automatic Emergency Torch   
This is a circuit for an emergency torch in which a bulb glows automatically when power goes off and switches off when power resumes.

Solidstate Auto Power off on Mains Failure   
This is a circuit that switches off the supply to electrical appliances when there is any failure in power supply. It is based on transistors and triac and doesn't draw any power when the load is off.

Short Wave AM Transmitter   
This is a circuit for a short wave AM transmitter that transmits signals at a fixed frequency of 12 MHz.

7MHz CW/AM QRP Transmitter   
This circuit can be used for either amplitude modulation (AM) or CW operation at 7 MHz by simply keeping a switch on or off for choosing any one between them.

Precison 1Hz Clock Generator Using Chip-On-Board   
This is a circuit that generates 1 Hz clock pulse using COB and a op-amp.

Tiny Dew Sensor   
This is a circuit for a dew sensor that turns off electrical appliances in case of excessive humidity.

Water level indicator With Alarm   
This is a circuit for a water level indicator with an alarm. It consists of twelve levels. The circuit sounds an alarm when the water is below the lowest level or is higher than the topmost level. Also it contains LEDs for each corresponding level to show the current status of water in tank.

Touch Sensitive Musical Bell With Timer   
This is a circuit for a touch sensitive musical bell with a timer that starts to play music when the touch plates are touched by hand.

Fire Alarm   
This is a circuit for a fire alarm that uses an LDR and a bulb to detect smoke generated after fire and raise an alarm through loudspeaker.

Contactless AC Mains Voltage Detector   
This is a circuit for an AC mains voltage detector that has an insulated sensing probe of length between 5 cm to 10 cm. When this sensing probe is taken in vicinity of AC mains the numbers in the display change repeatedly from 0 to 9 if it detects AC. If AC is not detected any random number is shown on the display.

Audio-Visual Extra Ringer For Phone   
This is a ringing circuit for telephones that uses a LED and an audio ringer IC to work as an extra ringing circuit which draws its power from telephone line.

Musical 'Touch' Bell   
This is a circuit for a musical bell that plays a sound when the touch plate gap is bridged by a fingertip.

Fastest-finger-first-indicator   
This is a circuit for a fastest finger first indicator which displays the persons assigned number in the display along with the sound of the buzzer.

Water-Level Controller   
This is a circuit for water level controller is based on transistors and relays. The circuit automatically switches on the pump when water is low in the tank and switches the pump off when water reaches a predetermined mark. It also prevents dry run of the pump in case the water level reaches a suction level in the underground tank.

Song Number Display   
This circuit displays the song track number in an audio system.

Telephone Receiver   
This is a circuit for a telephone receiver without a dialling section. It consists of a ringing section and a condenser mic.

LED-Based Message Display   
This circuit contains 172 LEDs that are used to display Happy new year 2004 word by word for one second each and then displaying the whole message for four seconds.

Digital Audio Video Input Selector   
This is a circuit for a digital audio video input selector that can add four audio video input to any standard colour television using a decade counter. A switch selects the number of the audio video input among the four that will be connected to TV.

Simple Intercom Circuit   
This is a circuit for a simple intercom that has been implemented using BEL circuit and amplifiers.

Programmable LED Indicator   
This circuit uses CD4017 to program a bicolour LED in ten different modes with combinations of red and green.

Blown Fuse Indicator   
It is a circuit that can check the status of a fuse. It has got a bi-coloured LED which turns to green if the fuse is fine and turns to red if the fuse is blown up. Modifications can be made for a buzzer to sound in case of fuse gets blown.

Simple Sensitive Remote Control Tester   
It is a circuit for testing of remote control transmitters. It contains a LED and buzzer who blink and beep respectively at the same rate of the incoming signal.

Water-Level Indicator Using 7-segment Display   
It is a circuit that indicates the level of water in a tank (low,half or full) on a 7-segment display. It uses a buzzer to alert the user about water overflowing from the tank.

Digital Timer Enhancement   
This circuit can activate or deactivate any electronic device connected to it at the time of alarm pre-set in a clock.

Staircase Light With Auto Switch-Off   
This is a circuit for a staircase light that turns off the light automatically after 40 seconds, hence saving power.

PC Multimedia Speakers   
This is a circuit for USB compatible low cost and low power multimedia speakers for PC.

House Security System   
This is a circuit for a home security system that sets off an alarm when someone interrupts a laser beam that continuously falls on LDR of the circuit. A combination of 6 plain mirrors is used to direct the laser beam around the house to form a net.

Digital Speedometer   
This is a circuit for a digital speedometer that can measure speeds upto 99 kmph with a resolution of 1 kmph.

Spy Ear   
This sound enhancer circuit can pick up distant sounds using a condenser microphone, and amplify them.

Automatic Light Controller Using 7806   
This circuit can be used to automate electrical light sources. It takes input in terms of a light dependent resistor (LDR) that can turn on the sources at night and turn them off during daytime. The circuit can be used for streetlights, tubelights or any other home electrical system that needs to be automated.

Antisleep Alarm for Students   
In this circuit a piezobuzzer beeps after a fixed interval. If the timer is reset then it will beep again after the same time interval. If the timer is not reset then the circuit switches off the lights and fans in the room.

Electronic Candles   
This circuit produces the flickering effect of candles in a light bulb.

Mini UPS System   
This circuit provides an uninterrupted power supply (UPS) to operate 12V, 9V and 5V DC-powered instruments at upto 1A current.

Short-Circuit Protection in DC Low-Voltage Systems   
This circuit is designed to provide short circuit protection to a main circuit to which it is connected. It features two LEDs - a red one to indicate a short circuit and a green one to show normal working. When this additional circuitry is shorted by excess voltage red LED starts glowing and green starts glowing when the short is removed.

Car Reversing Horn With Flasher   
It is a circuit that starts playing the car horn and flashing a light bulb in the rear of car whenever the car is in the reverse gear.

Transistorised Logic Probe for TTL   
This is a circuit for a logic probe that can be used for analysing and troubleshooting of the logic states for TTL digital devices. It has two LEDs that represent high logical level (green) and low logic level (red).

Inverter for Soldering Iron   
This is a simple but inexpensive inverter for using a small soldering iron (25W, 35W, etc) in the absence of mains supply. It uses eight transistors and a few resistors and capacitors.

Multitone Siren   
This is a circuit for a multitone siren that can produce sounds in five different audio tones. It is useful for burglar alarms, reverse horns etc., and is much more ear-catching than a single-tone siren.

Constant Current Battery Charger   
This is a circuit for a battery charger with protection for overcharge, short circuit and deep-discharge. It can charge 6V, 9V and 12V batteries. The charging current is one tenth of the batteries rating.

Liquid Level Alarm   
This is a circuit for a liquid level alarm. A sensor can be placed in the liquid tank. A beeping tone is generated from the speaker when the tank is full.

Generator Room Light   
This is a circuit for a light fitted in a generator room. The circuit can turn on the lights in the generator room automatically at night, and switch them off during daytime. Night and day are determined by using a light dependent resistor. An optional battery charger circuit can be connected to any external battery or battery in generator.

Skin Response Meter   
This is a circuit that measures changes in the skin resistance and shows the relaxation level of your mind. Blinking of red LED with low reading in the meter indicates a high level of stress. Blinking of the green LED, along with high reading on the meter represents a calm state of mind. Blue led is used to show human contact.

PC Power Manager   
This circuit can turn on or off all the peripherals connected to the computer when the computer starts up or shuts down.

Electronic Bicycle Lock   
This is a circuit for a electronic bicycle lock. It sounds a buzzer when the loop of the bicycle lock is broken. The buzzer can only be turned off by resetting the key switch.

Solar Panel based Charger and Small LED Lamp   
This is a circuit for a photovoltaic module that uses a solar panel to recharge a lead-acid battery. An additional circuit with an LED lamp is also present that can be powered either by Ni-Cd batteries or rechargeable batteries.

USB Power Socket   
This is a circuit that can convert the USB socket of a PC into a power socket. This power socket will deliver 5 V dc and 100 mA current which can be used for 5 V electronic portable devices. A cigar plug pin can also be connected with USB.

Remote-operated Master Switch   
A bedside master switch is used to switch on lamps both indoors and outdoors when there is a threat of intruder. This circuit can be used to activate the master switch from the bed without searching for the switch in darkness. It can be activated by the TV remote handset. The security lamps glow for three minutes and then turn off. The circuit is sensitive and can be activated from a distance of up to 25 metres.

Midnight Security Light   
This circuit thwarts theft attempts by turning on the lights in certain areas of the house at around 1 am by getting the desired time delay from a CMOS IC CD4060. The circuit is reset by using an LDR.

Laser-guided Door Opener   
This is an automatic door opener circuit that operates using a LASER diode. Whenever someone interrupts the laser beam the relay starts the door motor and the door is opened.

Traffic Baton   
These are two separate circuits for traffic baton. One of them has 20 red LEDs and 20 green ones arranged alternatively in a flasher. The other has two bulbs in the flasher. Both circuits use 6 V, 4.5 Ah rechargeable batteries.

Battery-level Indicator   
This battery level indicator circuit uses ten LEDs to show the level of charge in a battery. Each LED represents 10 percent of the battery level. So, the battery level can be measured to the nearest tenth level. It contains three groups of LEDs to represent the levels of battery charge; red, orange and green.

Wireless Switch   
This is a circuit that acts as a wireless switch for home appliances. One needs to move his hand between the infrared led and the phototransistor to interrupt the infrared beam and the appliance starts working through the relay. When the hand is removed from the beam the appliance stops working.

Muscular Stimulator   
It is a circuit that stimulates the nerves in the part of body where electrodes are attached.

Electric Window/ Fence Charger   
This is a circuit for electrifying a window or a fence for security. It uses IC 555 IC in free running oscillator configuration.

Portable Lamp Flasher   
This is a circuit for a portable dual flasher. It has two bulbs that glow alternatively and work as a dual flashing unit.

Car Anti-theft Guard   
This is a circuit for a car anti-theft system. Initially, when the circuit is on, an LED glows to indicate that the circuit is enabled. When someone opens the door, the circuit enables a buzzer which can be turned off by using the car key.

Smart Vibration Sensor   
This is a circuit for a vibration sensor circuit that produces a police siren sound via loudspeaker when a vibration is detected.

USB Power Booster   
This is a circuit for USB power booster that is designed to provide external power to type A USB connectors.

Tester For Remote Control   
This remote control tester circuit works using IR module TSOP1738 and its range is about 5 metres. When a remote control signal is detected in the circuit, a buzzer sounds to indicate the presence of the signal.

Current Sensor   
The circuit presented here senses the flow of electricity through the appliances and generate an audible beep after every fifteen minutes to indicate the ON state of device.

LED Lighting for Christmas   
This is a circuit that can be used as for festive decorations. It contains eighteen LEDs that can be assembled as one's wish.

Dice With 7-Segment Display   
This is a circuit for a dice with 7-segment display that can generate a random number from 0 to 9 and display it on a 7-segment LCD.

Seismic Sensor   
This circuit detects the movements of humans or animals. Whenever it detects any movement, a buzzer starts beeping and a red LED starts to blink.

Laptop Protector   
This is a laptop protection unit circuit that uses a homemade tilt switch. The switch activates the alarm whenever the laptop case is tilted.

Motorbike Alarm   
This is a circuit for a low cost motorbike alarm system that sets off an alarm whenever someone attempts to ride the bike or to move it. Then, after fifteen seconds it disconnects the ignition switch using relay.

Desktop Power Supply   
This is a circuit which converts the output of a computer SMPS into low voltage level ranging from 1.25 V to 9 V.

Shutter Guard   
This circuit contains a piezoelement that detects any vibrations in the shutter of a shop and activates a lamp and a police tone alarm signal.

Infrared Firecracker Igniter   
This is a circuit that can be used to ignite firecracker safely from a distance using an infrared module.

Mobile Shield   
This circuit works as a mobile anti-theft system. It produces a loud chirping sound whenever someone tries to take away the mobile and also works as a mobile charger.

Flying Saucer   
This is a circuit that can simulate effect of an UFO that consists of three circuits- rim flasher,dome flasher and sound generator. The rim flasher contains 16 LEDs arranged in a rim structure. Dome flasher contains three pairs of six LEDs arranged such that each group flashes at different rate. The sound generator generates sound for the UFO.

Automatic Phase Changer   
This is a circuit for an automatic phase changer that provides correct supply voltage in power lines through relays even when voltage is less in any of the phases.

Light Fence   
This circuit can sense the movement of a person within the range of three metres from a fence and produce a tone from the buzzer. This is used as a security system.

Anti-Collision Rear Light   
This is a circuit that contains four groups of high brightness yellow LEDs which flash one by one to work as a flashing system.

MAT Switch   
This circuit acts as a mat switch and can be put below the floor mat. Whenever some one will walk above it, the circuit will produce a beep sound. The touchpad switch is used in this circuit as an input.

5-Band Graphic Equaliser   
In this circuit, a 5 Band Graphic Equaliser is implemented using 5 opamps of IC NE5532 or LM833

Fully Automatic Emergency Light   
This is a circuit for an emergency light that automatically turns on when the supply is gone and turns off when supply resumes. It is rechargeable and stops charging the battery when the battery is full.

Clock Timer   
This is a circuit for a clock timer that can switch on electrical appliances at any time pre-set by user.

Electronic Horn   
This is a circuit for an electric horn that is built around a quadruple op-amp IC LM3900.

IR Music Transmitter and Receiver   
This IR music transmitter and receiver contains two circuits - one transmitter and one receiver. The transmitter transmits musical tones through an IR LED and the receiver receives those signals through a photo transistor. The musical tones produced are heard through the receiver's loudspeaker.

Secret Bell   
This is a circuit for a secret bell that uses a condenser which detects change in air pressure followed by breathing on the condenser. After getting signal from condenser, IC 555 generates a high signal for UM66 and a tone is generated.

Ultrasonic Proximity Detector   
This circuit uses transmitter and receiver ultrasonic modules that operate at 40 KHz to detect presence of any object in proximity and a decade counter converts it into a 4 Khz signal that is routed to earphones as an output.

Appliance Timer-Cum-Clap Switch   
This is a circuit for an appliance timer cum clap switch that can operate devices with a clap or can switch them on/off by setting an advance timer ranging from one second to 100 hours in advance.

Variable Power Supply Using a Fixed-Voltage Regulator IC   
This is a circuit for a variable power supply that uses a rotary switch to generate five output voltage levels of 5V, 6V, 8V, 9V and 12V after taking home AC supply as input.

Front Door Guard   
This is a circuit of a security system that consists of a reed switch in the heart of the circuit. Whenever someone tries to open up front door, it sounds a loud alarm and switches on the porch light.

Telephone operated Calling System   
This circuit can display a digit (from 0 to 9) dialled in a telephone over a display along with the sound of a buzzer.

Friendly Charger for Mobile Phones   
This is a charging circuit for mobile phones that charges mobile phones at 180 mA current at 5.6 V. It also includes a safety feature that puts a ten second gap in charging in case of resumption of power supply followed by a failure.

Bell-Cum-Light Controller   
This is a circuit for a bell and light controller that consists of a doorbell with porch light. When someone presses one switch, the bell rings and the light turns on for 3 minutes. Another switch turns on only the bulb for 3 minutes. A third switch just rings the bell. A fourth switch acts as a control for these three switches.

Speed Control of DC Motor Using Pulse-Width Modulation   
This is a circuit for a DC motor control using pulse width modulation that uses PWM to control a DC motor. The speed of the motor can be varied from 0 to maximum by using a variable resistor.


Hearing Aid   
This is a circuit for a low cost hearing aid that operates at 3 V.

Low-Power Voltage Doubler   
This is a circuit for a low power voltage doubler that can double an input voltage with an efficiency in the range of 75 to 85 percent.

Remote-Controlled Fan Regulator   
This circuit uses can control a fan's speed remotely by using an infra red receiver module with the help of a TV remote.

Multi-Melody Generator With Instrumental Effect   
This is a circuit for a melody generator that can provide various modes of melodies along with instrumental effect that can be chosen through dip switches.

Parrot Sound AC Doorbell   
This circuit uses a oscillator network of resistors and capacitors that generate a signal which after amplification from transistor gives a parrot-like sound in loudspeaker.

AC Mains Voltage Indicator   
This circuit has twelve LEDs that indicate the level of AC voltage variation visually from 160 V to 270 V with one LED indicating 160 V and then corresponding lighting of one LED each for an additional 10 V.

Quiz Buzzer   
This is a circuit for a quizzing buzzer that can be used for a maximum of eight participants.

Solar Lighting System   
This is a solar lighting system that uses a photovoltaic cell to charge a battery that can be used to light a lamp during night time. A transformer is also connected to charge the battery through AC.

Simple Short-Wave Transmitter   
This is a circuit for a simple short wave transmitter than can be tuned from 10 to 15 Mhz.

Picnic Lamp   
This is a circuit for a picnic lamp that can be activated for three minutes with a click of the fingers. It also give option to keep it on using a push-to-on switch.

Infrared Bug   
This is a circuit for an infrared bug that detect the presence of modulated infrared signals in its vicinity.

Versatile Power Supply   
This is a circuit for a versatile power supply that can provide voltage levels of 3.3V, 5V, 6V, 9V, 12V and 15V at a fixed current of one ampere.

IR Burglar Deterrent   
The circuit here sets off an alarm (siren sound) whenever infrared rays from an IR LED falling on its sensor are interrupted.

Shadow Alarm   
This circuit sounds an alarm along with the sound of a beep whenever a shadow falls on its photo sensor.

Versatile Water-Level Controller   
This is a circuit for a water level controller that turns on the motor whenever water is low below a pre set level in the tank and switches off the motor when the water reaches upto a certain defined mark. It switches off the motor in case of dry run when there is no water.

Automatic-Off Timer For CD Players   
This is a circuit that initiates a timer for turning off CD player as soon as the bedroom light is turned off. The circuit glows an LED before turning off the CD player to indicate user if he wants to keep CD player on. The time in which timer turns off CD player is about 45 minutes.

Sensitive Vibration Detector   
This is a circuit for a vibration detector that detects vibration through a piezoceramic element and activates a load connected to the relay.

Heat-Sensitive Switch   
This circuit uses a temperature to voltage converter that is used to control a relay. This circuit can be used to control any device's operation based on temperature.

Remote-Controlled Power-Off Switch   
This circuit uses a remote control to switch off electrical appliances by the help of a infrared receiver module.

Digital Dice   
This is a circuit for a digital dice that uses a binary counter and LEDs to generate random LED patterns corresponding to those of a dice.

Stress Meter   
This is a circuit for a stress meter that consists of three LEDs - green, red and yellow. Touch pads in the circuit measure skin resistance and calculate stress level. In case of relaxed state green LEDs light up while in the case of stressed state red LEDs light up along with sound of a buzzer.

Little Door Guard   
This circuit senses it when someone tries to open the door of house. It has an IR LED that sends a beam that is reflected from a mirror on door and is received by a phototransistor. When door is opened, the beam breaks and an alarm is activated.

Teleconferencing System   
This is a circuit for teleconferencing system that can be used to conference two telephone calls on two separate telephone lines.

Medium-Power FM Transmitter   
This is a circuit for a medium power FM transmitter that uses a 75 cm wire as an antenna to transmit FM signals up to 100 metres at 9 V.

Fuel Reserve Indicator For Vehicles   
This is a circuit for a fuel reserve indicator for vehicles that uses a tank mounted float sensor and a fuel meter and gives visual indications through LEDs to display various status of fuel level in a fuel tank. It shows indication for safe level, above reserve and danger level. In the case of danger level a buzzer beeps along with the indication of LED.

Smart Cellphone Holder   
This is a circuit for a small cellphone holder that is designed by using an IR LED and a phototransistor along with a 555. This circuit keeps searching for the phone and indicates through an LED when it doesn't finds it.

Safety Guard   
This circuit protects home appliances from voltage spikes by introducing a delay through an oscillator and relay setup along with CD4060. A switch is provided in the circuit to immediately start the appliances without delay.

Remote Control For Home Appliances   
This circuit can be used to turn off electrical appliances by using any remote from a maximum of ten metres distance.

Mains Supply Failure Alarm   
This is a circuit that alerts the user in case of mains supply failure by sounding an alarm, a back up light is also lit up.

Solar Bug   
This circuit takes power from a small solar panel and then produce a sound in a buzzer momentarily when the relaxation oscillator signal passes through it.

Micromotor Controller   
This circuit can control the direction of rotation of a DC micromotor by using push-to-on switches.

Simple Digital Security System   
This is a design of a simple security system that consists of three loops of wires raised above the ground namely loop 1, 2 and 4. Whenever any of the loops is broken a buzzer sounds and the loop number is shown on the display. If more than one loop is broken then sum of loop numbers is shown on display.

Atmel AVR ISP Dongle   
This circuit connects the ISP pins of AVR chip to computer's parallel port for programming.

Auto Turn-Off Battery Charger   
This circuit can be used to charge four AA type rechargeable batteries and disconnects the supply to cells when cells are fully charged.

Musical Light Chaser   
This is a circuit for a light chaser that consists of five 60 W bulbs arranged in a zig zag manner. The bulbs glow depending on the intensity of sound. In low intensity only one bulb lights up and in maximum intensity all bulbs light up.

Audio Amplifier for Personal Stereo   
This is a circuit for an audio amplifier for a personal stereo system.

Water-Level Controller   
This is a water level controller that uses two floats to control the switches to operate a motor whenever water level goes beyond the minimum/maximum points in the tank.

Hit Switch   
This is a circuit for a hit switch that uses a piezoelectric diaphragm to work as a switch for electrical appliances. One hit on the diaphragm switches on the appliance and another hit turns it off.

Electronic Watchdog   
This is a circuit for a electronic watchdog that sounds an alarm whenever some one interrupts the IR beam between IR LED and IR receiver module.

Fire Alarm Using Thermistor   
This is a circuit for a thermistor based fire alarm that uses thermistor as heat sensing element. Whenever temperature increases beyond 100 C the thermistor provides a low resistance as a result of which a speaker is driven that produces a sound.

Anti-Theft Alarm For Bikes   
This circuit uses a combination of IR LED and IR receiver module aligned in such a way that the circuit is connected through a beam in normal position. When someone tries to move the bike, the beam breaks. An alarm is generated to indicate the theft attempt.

Automatic School Bell   
This is a circuit for a automatic school bell that rings a bell automatically after 45 minutes to indicate one period of school and after 30 minutes at the end of fourth period to indicate lunch period.

Solidstate Remote Control Switch   
This is a circuit for a remote controlled switch that contains transmitter and receiver circuits that can be used to switch on/off electrical appliances.

DC Motor Control Using A Single Switch   
This is a circuit that controls a DC motor to run it in clockwise, anti clockwise direction and to stop it using a single switch. It has three LEDs that indicate the status of motor; stopped, forward rotation and reverse rot