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Digital electronics projects pdf

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Electronics. Projects. FOR. DUMmIES‰ by Earl Boysen and Nancy Muir . on interesting book projects and to Chris Morris for managing the editing process. Digital Electronics with Industrial. Project. MEng Honours. UCAS code H 4 years. This four-year MEng degree in digital electronics integrates a year of. Analysis, Design, and Characterization of a Digital Alarm Clock consists of using your knowledge gained so far in digital electronics to.


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Library of Congress Cataloging in Publication Data. Hawkins, Harry M. Digital electronics projects. Includes index. 1. Digital electronics-Amateurs' manuals. It is the big collection of ideas to do some innovative project, to make This circuit is designed around digital IC which is NAND gate. Explore Digital Electronics Project| Electronics Project Pdf, Electronics and Telecommunication Engineering ECE Project Topics, IEEE Robotics Project Topics or.

In phase with output. The load in the above circuit is the light bulb. So an autoamted toll collection system was proposed here. 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. This is a simple project, you can do it yourself.

The light sensor in this circuit senses the car back light and turn on its indicator to help driver see the indicator.

Identify the positive and negative ends of LED and positive should be connected to Ohm resistor. This circuit can be used in many other ways also. Flip-Flop In this section we will make: Op-amps or other devices cross-coupled by resistors or capacitors. Assemble the circuit making sure that electrolytic capacitors are the right way round.

The circuit presented here is a particular multi-vibrator known as astable multi-vibrator. It is characterized by two amplifying devices transistors. What is it about? A flip-flop or multi-vibrator is an electronic circuit used to implement a variety of simple two-state systems such as oscillators.

And that the transistor leads are not touching each other where they come out of the bottom the transistors. The LED in this circuit flashes alternatively because each transistor is switched On and Off in turn due to C1 charging and discharging through R2 and C2 doing same through R Lets try to understand the functioning of flip flop by analyzing circuit given below. If all is well.

An astable multi-vibrator is a regenerative circuit consisting of two amplifying stages connected in a positive feedback loop by two capacitive -resistive coupling networks.. The circuit is usually drawn in a symmetric form as a crosscoupled pair and each element of pair have two states On and Off.

The amplifying elements used here are transistors. Join more LEDs in parallel. Similarly if you decrease the value of capacitors then blink rate will be faster as capacitors will get discharged quickly. If LEDs are not flashing close switch Complex. We have tried to simulate real circuit in the figure on left side. Lengthen the switch wires to insert them in breadboard. Step 5: Use snap to screw the battery.

Lets assemble the circuit on MY Kit and make a demo project for your lab or for science fair. In battery red wire shows positive terminal and black is negative. Longer lead of LED is positive Step 2: Cut the panel design page shown in the figure on right and paste it on MY Kit. And you Kit is ready to use and demonstrate how a flip flop oscillator circuit works.

Step 4: The resistance color bands are taken true to actual values. If switch is On. I tried white and blue LEDs alternatively. You can also redesign the panel drawing and make more cool designs. Do send it to us at: Try out the panel shown in the figure on right. If you are able to make a very cool design. It is designed for use in bells. The heart of this simple circuit is music IC UM Do not provide more then 4. Identify the pins of IC UM66 and transistor.

UM66T is a melody integrated circuit. It has 62 notes ROM to pl ay music. Not our own. Identify Piezo speaker pins and it should be connected in correct direction. For example. The tone generator is a programmed divider which produces certain frequencies.

It has an inbuilt tone and a beat generator. Melody Circuit In this section we will make: Assemble the circuit. Pre-recorded one. Many versions of UM66T are available which generate tone of different songs. In this circuit.

Latest Digital Electronic Projects in 2014

If you don't listen to any sound. You can also use a speaker instead of piezo. Melody Circuit Tip: Loud Melody Circuit Indentify the pins of IC and transistor. Assemble the components and switch On the circuit. You can use this circuit in any another projects also.

Your circuit is ready. It needs very less current to turn LED On and the conby thrice or more. This configuration gives a much higher common-emitter current gain than each transistor taken separately. BC Step2: Discover more from transistors. Lets first try to make a simple circuit and then use the circuit for further projects.

Try to short them and see if Tip: You can increase the sensitivity of this LED is glowing up. In some application the amount of input current available to switch on a transistor is very low. Use a switch between open points or use wires. This may mean that a single transistor may not be able to pass sufficient current required by the load. This can be achieved by using a Darlington Pair. In electronics. Darlington Pair In this section we will make: Lets try to make a simple circuit using Darlington pair and melody circuit together.

Assemble the circuit on MY Kit to put it on display or for working. Water gets overflow and creates mess. Remove the switch and lengthen the wires to use them to insert in water tank. If you forget to close pump switch on time.

You can also find a box enclosure to assemble this circuit permanently in it. Previous circuit components and 1. In the Darlington pair circuit just made above. Panel for Water overflow Alarm Tip: You can use a loud melody circuit with the Darlington pair circuit.

Zoom this document to see resistance color codes. LED should light up with ringing melody. Please refer the previous melody project to make the circuit. Instead of inserting the probes directly to water tank use corrosion tolerant steel bolt. Assemble the melody circuit in breadboard. Connect the melody circuit to LED pins. So that melody circuit will also get power when LED will light up.

This will ensure smooth working of your device for longer time. Switch On the circuit and touch short the two probe wires. In this project we are going to make a small fire alarm which can be installed on places like kitchen. The circuit is same as previous one. It protects us from unknown fires and give time to prevent any miss happening. A smoke alarm is more effective which is generally installed on roof and detects smoke. It senses fire from close range so it can kept near to the places.

Be patient with this circuit. If it doesn't glow up circuit needs calibration. As done before. For melody circuit. If you are really intending to use candle flame.

Fire Alarm Step1: In the Fire alarm circuit. As it requires calibration. You may use ice instead of hot objects to calibrate correct position of variable resistance knob. Rotate the variable resistance knob to increase resistance and touch the hot object again to sensor and see if it works. Switch On the circuit and touch thermistor with a hot object. Battery 6volts. This gadget is designed to sense the light and it can wake you up with first sunlight for sure.

Switch On the circuit probably in some dark room. Assemble the melody circuit in breadboard first. If circuit is working fine. The alarm will sound. The moment you stop falling light on LDR. With the help of mirrors See image below you can divert laser on different angles in room in such a way that finally the light must reach to this sensor.

If any of the laser path is obstructed by anybody. When this constant light source falling on Light sensor LDR is broken by some body. Test the circuit in a dark room with Laser light over LDR. If you are using a 9volt battery. You can optionally use mirrors to divert Laser to different angles in room. In this project we will create a real burglar system operated by laser lights. In the previous circuit.

With this gadget you can sense the wire going through the wall. It detects the electric field created by live wires and indicates you their position inside wall. Its very difficult to catch it. Identify the positive and negative wires of LED.

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Just use the touch plate to touch the wall or pipe in which wire are passing through and see the indicator. The tone generator is a programmed divider which produces certain frequencies.. Apart from previous components we need 1 BC Melody Circuit Step1: The three highlighted 5k resistors shown in figure are the reason why this IC is named as Provides "control" access to the internal voltage divider by default. Positive supply voltage. This is made to indentify the first pin of IC.

The internal components of as shown in figure consists of 2 comparators and a flip flop. A timing interval may be reset by driving this input to GND. Open collector output which may discharge a capacitor between intervals. All of these components contain 25 transistors and 15 resistors packed in the IC. This is a low cost. In phase with output.

This output is driven to approximately 1. Assemble all remaining parts and insert the batteries at the end. Bistable mode or Schmitt trigger: IC More Ideas You can add more resistances in increasing order and more push buttons to extend your piano keys.

The can be used as a simple ADC. Ensure that electrolytic capacitors are right way round. Uses include bounce-free latched switches. Also you can experiment with the existing resistances which will change the sounds of piano. Identify the different resistors with there color codes.

Electronics projects pdf digital

The use of a microprocessor based circuit can then convert the pulse period to temperature. Uses include LED and lamp flashers. Ensure all the pins of IC are properly inserted. This is it. 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.

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. Sun Tracking Solar Panel: This article describes about circuit that rotates solar panel.

Projects pdf electronics digital

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.

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. Stepper Motor Interfacing with Microcontroller: The main principle of this circuit is to rotate the stepper motor step wise at a particular step angle.

The ULN IC is used to drive the stepper motor as the controller cannot provide current required by the motor.

A mobile controlled Garrage door opening system is proposed here. This system uses a DTMF technology for controlling the door. Solar Battery Charger Circuit: Here is the simple circuit to charge 6V, 4. 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. Here is a best example for simple LED blinking ligts i.

This circuit can be used for decoration purpose or can be used for a signaling purpose and many more. 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.

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. Audio Tone Control Circuit: This article explains you how to design an audio tone control circuit with the gain of around This design needs less number of components and it is cost effective.

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.

Remote Control Circuit through RF without microcontroller: Here we have used RF MHz modules to make wireless remote. Using this remote, we can control the appliances within the range of meters. It is used for remote control applications like burglar alarm, car door alarm, calling bell, security systems, etc. This simple RFID based attendance system is designed using ATmega8 Microcontroller and is mainly used in educational institutions, industries, etc.

Reverse Parking Sensor Circuit: If you are a new driver then it is very difficult to judge the distance while parking the car. We can easily arrange this system at the back side of the car. Remote Operated Spy Robot Circuit: This is a simple spy robot circuit which can be controlled by the remote. The maximum controllable range is meters. It is used to observe the behavior of wild animals where human beings cannot reach.

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. 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. 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. 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.

This circuit produces a sound similar to the police siren. You may also get detailed information about pin diagram and internal block diagram of NE timer. Police Lights using Timer: This circuit simulates the police car lights by alternate flashing. This flashing action performs continuously. This circuit uses timer and a decade counter. 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.

This saves the power consumption and is low cost. This circuit can be used in the museums to protect the valuable things.

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

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. Morse Code Generator Circuit: This is a circuit used to generate morse code.

Morse code is very old and versatile technique to send text messages using wireless media. 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. 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. Mobile Jammer Circuit: This circuit is used to block the signals of cell phones with in the range of meters. This circuit can be used in TV transmission and also for remote controlled toys or play things. This is a simple circuit which is more useful to save our resources, energy and money by installing in your homes.

Luggage Security Alarm: This is a simple alarm circuit which helps in ringing a warning alarm when someone tries to steal the luggage. Low Power Audio Amplifier using Timer: This is a simple low power audio amplification circuit designed using timer.

It can be used to develop low power music systems used in vehicles. This line follower robot is a basic robot that follows a specific path indicated by a line having some particular width. Light Activated Switch Circuit: This circuit can be used in security applications like when there is darkness on the LDR, it stops lighting. 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.

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 LM LED Interfacing with The main principle of this circuit is to interface LEDs to the family micro controller. Commonly, used LEDs will have voltage drop of 1.

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This is applied through the output pin of the microcontroller. 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. This is a simple circuit used to decorate your house by building christmas lights using LEDs. 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.

200+ Best & Free Electronics Mini Projects: Circuits, Working Process, Code, Step by Step Guide

LC Meter using Timer: This is a simple LC Meter circuit designed using Timer and microcontroller. It is mainly used to measure value of a reactive element like a capacitor or an inductor. CD is a JK flip flop that is generally used for data storing. 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.

DC Motor Interfacing with Microcontroller: Here is a simple but very useful circuit in our real life named interfacing DC motor with microcontroller. Interfacing 7 Segment Display to 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. The Atmega16 belongs to the AVR microcontroller family.

This is a simple circuit diagram which helps to describe interfacing of 16X2 LCD module to AT89C51which is a family microcontroller. 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.

This is a simple IC testing-circuit which tests your entire timer IC. So before using your IC, you may check whether your IC is good or bad by using this circuit. 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. 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.

Frequency Counter Circuit: Here we design a simple frequency counter system using two timers and two counters. 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.

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. 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.

250+ Electronics Mini Projects Ideas for Engineering Students

This is a simple alarm circuit which helps in ringing a warning alarm when someone tries to steal the luggage. This circuit helps you to manage your appliances in your home by just clap without moving from your bed. This is accomplished using a capacitor-based power supply. This is a low cost and efficient circuit and can be used at homes.

This is a simple a simple LED cube circuit designed without using the microcontroller. It is based on the principle of driving LEDs using the clock pulses. Here is the monostable multivibrator circuit diagram and working.

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The multivibrator is an electronic circuit which will work as two-stage amplifier operating in both stable and a stable mode.

This is a circuit used to generate morse code. Morse code is very old and versatile technique to send text messages using wireless media.

Projects pdf electronics digital

The trigger pulse, produced by pressing the button, must be of shorter duration than the intended output pulse. In this circuit, there are three resistors named R inside it and all have equal values. 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. This is a simple circuit which is more useful to save our resources, energy, and money by installing in your homes.

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 LM This Voltage regulator circuit is used to get fixed voltage at the output without depending on the input voltage. This is a simple circuit used to decorate your house by building Christmas lights using LEDs. It is mainly useful to music lovers. This air flow detector circuit can be used to detect the flow of air in areas like a car engine.

It can also be used as a temperature detector. Here we designed a power amplifier circuit using push-pull class AB configuration to derive a power of W to drive a load of 8 Ohms speaker. 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. The main principle of this circuit is to display the digital temperature value.

These are mainly used in environmental applications. This is a simple circuit that displays count from 0 to 59, representing a 60 second time interval. It consists of a timer to produce the clock pulses and two counter ICs to carry out the counting operation. It produces different tones or sounds depending on the frequency range.

This simple RFID based attendance system is designed using ATmega8 Microcontroller and is mainly used in educational institutions, industries, etc. This is a simple low power audio amplification circuit designed using timers. It can be used to develop low power music systems used in vehicles.

The Atmega16 belongs to the AVR microcontroller family. CD is a JK flip-flop that is generally used for data storing. 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. This is a simple and funny game circuit which contains 10 LEDs that are moving in an arbitrary fashion and we must target a particular LED given by your challenger.

A multiplexer is a circuit that accepts many inputs but gives only one output whereas a demultiplexer accepts only one input and gives many outputs.

Get an idea about their circuit diagram and pin diagrams in this post. It is very flexible and is employed in many circuits like a voltage regulator. Here we have shown how to design these basic logic gates using one of the universal gates — NAND Gate. This circuit produces a sound similar to the police siren. You may also get detailed information about pin diagram and internal block diagram of the NE timer.

We built the circuit using a microcontroller which scans the input from push buttons and displays the corresponding number on a display device. 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. Two identical circuits are needed, one is for left and the other is for the right. The main heart of this circuit is timer. This circuit simulates the police car lights by alternate flashing.

This flashing action performs continuously, and this uses timers and a decade counter. This is ding dong sound generator circuit is designed using timer IC in astable mode.

It can be used as the doorbell. With some modifications, it can be used to produce different sounds. Read this post for complete details. This saves the power consumption and is low cost. This circuit can be used in the museums to protect the valuable things. 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.

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. Here we have used RF MHz modules to make a wireless remote. Using this remote, we can control the appliances within the range of meters.

It is used for remote control applications like burglar alarm, car door alarm, calling bell, security systems, etc.

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.

Its cost is less as compared to voltage stabilizers. Here is a simple circuit to charge 6V, 4. 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.

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. In this project, we are designing the circuit which is used to detect and control the water level automatically in an overhead tank using microcontrollers.

It is used in industries to control the liquid level automatically. The main principle of the circuit is to flash an LED for every 5 seconds.

The circuit consists of timer IC as the main component. 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 leds. We can easily arrange this system at the back side of the car. This is the simple and cost-effective automatic emergency light circuit with light sensing.

This system charges from the main supply and gets activated when the main supply is turned OFF. This emergency lamp will work for more than 8 hours. 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 play a main role in the circuit. 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 the circuit automatically charges the battery. This circuit can be used in security applications like when there is darkness on the LDR, it stops lighting. This is a simple spy robot circuit which can be controlled by the remote.

The maximum controllable range is meters. It is used to observe the behavior of wild animals where human beings cannot reach. This is a simple digital voltmeter circuit designed using microcontrollers. This circuit measures the input voltage from 0V to 5V. This circuit explains to you how to measure the distance using microcontrollers. This ultrasonic rangefinder system measures the distance up to 2. The main principle of this circuit is to rotate the stepper motor stepwise at a particular step angle.

The ULN IC is used to drive the stepper motor as the controller cannot provide the current required by the motor.

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.

In this project, about timers in microcontrollers and how to generate a delay using timers. This article describes you how to interface seven segments to the AT89C51 microcontroller. This system displays the digits from 0 to 9 continuously with a predefined delay. This is a simple LC Meter circuit designed using Timer and microcontrollers. It is mainly used to measure the value of a reactive element like a capacitor or an inductor. 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. Here is a simple but very useful circuit in our real life named interfacing DC motor with microcontrollers.

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. 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. The main principle of this circuit is to interface LEDs to the family microcontroller. Commonly, used LEDs will have a voltage drop of 1.

This is applied through the output pin of the microcontroller. The main principle of this circuit is to produce a wailing siren. The timer IC is operated in a stable mode.

When the switch is pressed, the speaker produces high pitch siren and when it is released, its pitch decreases and is switched off after 30 seconds. This article explains to you how to design an audio tone control circuit with the gain of around This design needs less number of components and it is cost effective. 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.

This circuit mainly works on the principle of mutual inductance. This circuit may be used as wireless power transfer circuit, a wireless mobile charger circuit, wireless battery charger circuit, etc.

This article explains to you how to 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 the battery. FM Radio circuit is the simple circuit that can be tuned to the required frequency locally. This article describes the circuit of the FM radio circuit.

This is a pocket-sized radio circuit. It may be used as an emergency light and also as a reading lamp. In this interfacing of GPS with circuits, GPS module calculates the position by reading the signals that are transmitted by satellites. RTC is an integrated circuit which keeps track of current time. This circuit helps to generate a random number in between 0 to when the push button is pressed and it may be used in the games like monopoly, snake ladder.

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 the audio signal.

This simple IR audio link circuit is used to transmit audio signals wirelessly. This IR audio link is able to transmit audio signals up to 4 meters. This mobile controlled home automation system is designed without using a microcontroller. We can also control a robot using this technology by making some modifications. 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.

This circuit displays the time on LCD. For this clock, we can set the time at any instant. Here the clock works in hour mode and the RTC chip is configured by programming controllers.