Top Circuits Page 172
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Most homes today have at least a few infrared remote controls, whether they be for the television, the video recorder, the stereo, etc. Despite that fact, who among us has not cursed the light that remained lit after we just sat down in a comfortable chair....
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How often does it happen that you close down Windows and then forget to turn off the computer This circuit does that automatically. After Windows is shut down there is a click` a second later and the PC is disconnected from the mains. Surprisingly enough,....
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The alarm may be used for a variety of applications, such as frost monitor, room temperature monitor, and so on. In the quiescent state, the circuit draws a current of only a few microamperes, so that, in theory at least, a 9 V dry battery (PP3, 6AM6,....
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You can save on your electricity bills by switching to alternative sources of power. The photovoltaic module or solar panel described here is capable of delivering a power of 5 watts. At full sunlight, the solar panel outputs 16. 5V. It can deliver a current....
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Normally home appliances are controlled by means of switches, sensors, etc. However, physical contact with switches may be dangerous if there is any shorting. The circuit described here requires no physical contact for operating the appliance. You just need....
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This circuit can be built from readily available low-cost components, some of which may even be hiding in your junkbox! The indicated value of 22 for resistor R1 causes an average current of about 65 mA through infrared emitter D1. Because the IRED is....
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You cannot beat the Chinese. The project described in this article is a ready-made item from a $2. 00 shop! And it is made in China! It is a wireless doorbell with a cost of about $10. 00. It is so cheap, you could not build it from components for $10. 00!....
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As time goes by, microcontrollers become more powerful, cheaper, and smaller. A typical micro of the past could have had 40 pins and no internal memory. On the contrary, modern J-series PICs are made with 96K program memory and 28 pins. We can drive a lot of....
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You need not be disappointed next time when your digital camera shows low battery indication during a picnic trip. Just plug this digital camera adaptor into the cigarette lighter outlet of your car and connect the camera to it. The adaptor will interface....
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This 7-digit combination lock can be easily hard-wired for any combination that you choose. The circuit uses a 4-bit, divide-by-8 Johnson counter (IC1), ten push button switches and NPN transistor T1. At power-on, ` capacitor C2 connected to pin 15 of IC1....
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This circuit features automatic exit and entry delays - an optional instant alarm zone - an optional intermittent siren output - and an automatic reset. By adding external relays you can immobilize the vehicle and flash the lights. The alarm is set by....
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Here is one of the interesting 555 timer circuits to trick your friends while studying electronics in schools. Clap switch circuit is the local name of sound controlled flip flops. This sound controlled light can also be used as sound detection sensors. Flip....
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The process of converting an analog voltage into an equivalent digital signal is known as Analog to Digital Conversion, abbreviated as ADC. An ADC is an electronic circuit which converts its analog input to corresponding binary value. The output depends up....
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Astable Multivibrator can be designed by using 555 timer IC, Op Amps and also using transistors. The 555 IC provide accurate time delay from mille seconds to hours. The frequency of oscillation can be controlled manually by simple modification. This is a....
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Transistor is a semiconductor device used for switching and amplification of weak signals. This article explains how a transistor work and the working of transistor as a switch. At present, transistors are applied in most of the electronic equipments for....
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We can also take output from collector terminals of the transistors, such circuit is show below. To know the working of below circuit you must read How transistor acts as a switch ..
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In binary phase shift keying (BPSK) modulation scheme, the phase of a carrier is changed in accordance with the digital pulse signals. BPSK modulator is basically a phase modulator. Here the transmitted signal is a sinusoid of fixed amplitude. It has one....
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What is DAC Digital to analog converter (DAC) is used to get analog voltage corresponding to an input digital data. Data in binary digital form can be converted to corresponding analog form by using a R-2R ladder (binary weighted resistor) network and a....
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Inverting amplifier is one of the most popular Operational Amplifier circuits. The output changes in such a way that tries to avoid saturation and counteract the change caused by the input. This makes the amplifier stable. The amplifier tries to resist....
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Operational amplifier based triangular wave form generator is simple circuit that is widely used in function generators. Here is the circuit for Triangular wave generator using 741 op amp. We know that the integrator output waveform will be triangular if the....
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Automatic water level controller circuit is a simple engineering project. It can automatically switch ON and OFF the domestic water pump set depending on the tank water level. You can implement this motor driver circuit at your home or college using less....
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Binary Amplitude Shift Keying (BASK) or On Off Keying (OOK) is one of the digital modulation techniques in which the amplitude of carrier is switched according to the binary data. This digital modulation scheme is used to transmit digital data over optical....
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Here we define 7 levels in thereservoir. The sensed values are connected to an encoder circuit. The encoder circuit consist of a 74148 IC, which is a 8 line to 3 line encoder. Next section is the HEX Display` which is a special type of 7 segment display. It....
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Here I will show you an audio amplifier circuit that can be used for walkie talkies, low power transmitters, and packet radio receivers. A condenser mic audio amplifier gives good quality audio of 0. 5 watts at 3 volts. Here we are going to make use of BEL....
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In this article we will be discussing about a home security alarm circuit. This is a LPG gas leakage sensor circuit that detects the outflow of LPG gas and alerts the user via audio and visual indications. The heart of this simple engineering project is a....
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Monostable 555 timer multivibrator circuit (one shot monostable multivibrator) is a retriggerable mono shot pulse generator. The name Mono stable` indicates that it has only one stable state. The unstable state is called Quasi stable state`. The duration of....
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This article gives the FM transmitter circuit schematics with necessary explanation. The main component used here is the VMR6512 IC which is a highly integrated FM audio signal (Hi-Fi Audio FM) transmitter chip. You can use this as FM radio transmitter for....
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Summing amplifier or an adder is used to sum two signal voltages. Voltage adder circuit is a simple circuit that enables you to add several signals together. It has wide variety of applications in electronic circuits. For example, on a precision amplifier,....
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Here we are going to discuss about a simple timer IC 555 project. The 555 timer IC can be used as an audio amplifierwithastable multivibrator configuration. It functions as to carry outpulse width modulation (PWM) of audio signal. Current(I) capacity of 555....
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This is a very useful and simple circuit diagram for amplifying weak signal from a capacitive condenser microphone. You can use this circuit for sound sensing applications and some automatic robotic sensors. We have already posted an efficient audio....
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How can we rotate a DC motor in clockwise and anti clockwise directions Or how can we rotate a motor in forward and reverse direction These are the popular question asked by many of the robotic beginners. DC Motor (control) driver circuits are the essential....
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The Johnson digital counter or Twisted Ring Counteris a synchronous shift register with feedback from the inverted output (Q`) of the last flip-flop. Q` of the last flip flop is connected back to the input D of the first flip-flop. This inversion of Q before....
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Here is a simple engineering project circuit of handy mobile cell phone detector (sniffer). This pocket-sizedmobile communication detector or sniffer can sense the existence of a mobile device. So it can be used to avoid the use of mobile phones in private....
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How to create dual power supply unit using single battery for your lab prupose Dual voltage power supplies are required particularly for op amp experiments and some of the instrumentation amplifiers. Some low power audio pre amplifiers also uses dual voltage....
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This is a simple 12V rechargeable smart battery charger circuit. You can use this best battery charger circuit as car battery chargers, Inverter battery charger, Emergency light battery charger etc. An automatic indicator alarm circuit also comes along with....
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This simple low power dc to ac inverter (dc to ac converter) circuit converts 12V DC to 230V or 110V AC. By doing simple modification you can also convert 6V DC to 230V AC or 110V AC. It can be used as inverters for home needs to enable light loads (electric....
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Water tank overflow liquid level sensor alarm circuit is a simple electronics project for school students. In the previous articles we had discussed about numeric water level indicator and water level controller circuit, but those circuits are much complex....
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Here is a new audio power amplifier schematic built around TIP darlington pair transistors. You can use this circuit for home audio power amplifiers and car audio amplifiers. The TIP142 and TIP147 darlington pair transistors forms a push pull high power....
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Zero crossing detector(ZCD) is a voltage comparator that switches the output between +Vsat and Vsat (Vsat: Saturation voltage almost equal to 14V) when the input crosses zero reference voltage. Then what is a comparator In simple words comparators are basic....
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Here i-St@r comes with thesimplest mini audio amplifier circuitschematicusing LM386 low voltage audio power amplifier IC. This circuit is applicable to power medium sized speakers from a music player that can only drive earphones (lm386 headphone). The LM386....
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How to measure water purity How to test water quality using a simple electronics project You can perform water purity measurement and water quality analysis using this water purity checker circuit. This circuit is built around a simple LDR (Light Depended....
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Wien bridge oscillator is an audio frequency sine wave oscillator of high stability and simplicity. Before that let us see what is oscillator An oscillator is a circuit that produces periodic electric signals such as sine wave or square wave. The application....
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Have you ever thought aboutimplementing your own home security alarm systems It`s one of the simplest and interesting circuits for electronic beginners. Our new home security equipment uses aLDR (Light Depended Resistor) to detect security problems. Theft....
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This article explains What is inverter And how can you construct your own simple low cost 12V to 220V inverter circuit. An inverter is nothing but a DC to AC converter. Inverters are very useful electronics products for compensating emergency power failure,....
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Here is a simple PWM dc to ac voltage inverter circuit based on IC SG 3524. The SG3524 IC chips is a fixed frequency PWM (Pulse Width Modulation) voltage regulator control circuit, with indifferent outputs for single ended or push pull applications. The....
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This is a simple 2N2222 transistor based radio FM transmitter circuit within the FCC (Federal Communications Commission) limit, that is no license is necessary for using thisstable FM transmitter circuit. What is an FM transmitter FM stands for Frequency....
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This is the most simplest and single transistor FM wireless transmitter circuit that ever posted in CircuitsGallery. In telecommunication field, frequency modulation (FM) transmits information by changing the frequency of a carrier wave according to message....
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This is a MOSFET transistor based power amplifier circuit that can be operated between +35V to -35V range. The input voltage is pre filtered and pre amplified before applying to the MOSFET switch. The pre audio amplifier is a differential amplifier section....
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We know that astable multivibrator is simply an oscillator circuit that produces continuous pulses without the help of any external triggering. The oscillation frequency and time period can be manually controlled through simple modification of resistors and....
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I have posted wide varieties ofsmall electronic projects onwater level sensor in Circuits Gallery. This is another project for school students to detect the water level inside a water tank or any other water reservoir. We can call this as a liquid level....
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Voltage fluctuation is a serious issue in every home. Due to some reasons our supply voltage may rise above 110V or 230V. Flow of this high electricity may lead to the damage of our home electrical devices. Have you thought how electrical protection is....
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Digital counters have several applications in electronics circuits. Counters in digital electronics are used at different situations. Here we are going to deliver the idea of aRing counter circuit, which is a register counter. Working animation and circuit....
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In this section we would like to introduce you a transistor oscillator circuit, called as RC Phase shift Oscillator. First of all we need to know what is an oscillator. An oscillator is an electronic circuit which acts as a sine wave generator. The only....
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Intercom or Inter communication circuit is a two directional communication system. It provides a reliable communication line and is extremely easy to implement. The circuit is prepared by an amplifier, two switches and two loudspeakers. We can extend this....
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Zener diode regulator is a basic electronic circuit which is very useful for those interested in hobby circuits. This circuit is used for obtaining a regulated voltageat the output which can be used for biasing other circuit elements. Now how to use zener....
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At many situations we need to display the amount of battery charge through some kind of indication methods like LED dot display or LED bar display. Here CG comes with a battery charge indicator circuit using LED dot display. This battery power level....
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Here we are going to discuss about an Asynchronous 4 Bit Binary Up Counter, a circuit made up of several J-K flip-flops cascaded to generate four bits counting sequence. An up counter is basically a digital counting circuit which counts up in an incremental....
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How to change the brightness of aLED Whether led lights are dimmable Is it possible to adjust the brightness of LEDs LED is basically a diode, when the forward voltage exceeds 0. 7 volt, it starts to glow, and if the forward voltage is less than 0. 7 volt,....
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How to build a voltmeter for DC voltage measurements without using multimeter testing This is a simple digital voltmeter circuit that can measure voltages from 0V to 9V. The main part of this circuit is a dot bar display driver IC LM3914. Input voltage....
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Solar energy has now become a popular alternative for the production of electricity. Here is a green energy project for school students on how to make solar lamps for your home. The main component of this simple solar lamp circuit is a small solar panel and....
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This is a simple DIY charge controller schematic posted in response to a request by one of our readerson our facebook page. The main component of this auto battery charger circuit is a 555 timer which compares the voltage in the battery. It turns ON the....
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Here is a hobby circuit of a multi channel remote control system, by which you can control 8 different appliances. The main sections of this multi channel remote control circuit are the RF receiver and transmitter. By using this circuit we can control 8....
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Have you seen Audi, Lexus or Ford rain sensing wipers and wondered how they work in these vehicles They are handled by sensors at the center of the windscreen which detects rain water and turns on the wiper motor. Here is the working of rain sensitive wipers....
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When ever you need to get an alarm or intimation after ten minutes, the circuit shown below can be used. The circuit is nothing but a monostable multivibrator based on IC NE 555. When ever you press the reset push button the green LED D1 glows after 10....
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Hi-fi 100W mosfet power amplifier circuit . Operates from 45v dual supply. 100W to 8 ohm speaker, 160W to 4 ohm speaker, low distortion....
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Reliable 10A adjustable voltage regulator based on MSK5012. 1.3 to 30V output voltage range. Low ripple and high efficiency....
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Here is a simple and effective circuit for driving florescent lamps from a 12 V supply. The circuit is nothing but consists of an oscillator, a MOSFET switch and a step-up transformer for driving the florescent lamp. The IC1 TLC 555 is wired as an astable....
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This voltage regulator circuit can deliver up to 3A at 12V output voltage. The circuit can be employed on occasions when a current of more that 3A is demanded for regulator. IC regulators of such high current rating are pretty hard to find. The transformer....
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Here is a simple yet powerful circuit that can be used for flashing 12V lamps especially that is used on automobiles. The flashing circuit is based on transistor Q1(BC557) and MOSFET Q2 (IRF530) where the Q2 provides the necessary drive for the lamp. Any....
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A simple 12V to 24V dc dc converter circuit with diagram built around LM324. This boost converter with schematic can provide up to 800mA output current and a steady 24V DC....
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This 1. 3V power supply can be used as replacement for the 1. 3V Mercury Cell in any circuit. When the input 5V is given to the circuit, the voltage drop across zener diode D1 will be around 2V. The diode D2 will drop a 0. 7 V from the 2V volt and the....
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15 Watts Class B Audio amplifier circuit. This 15W amplifier circuit is designed using a dual op-amp LM833. Diagram and Schematics are shown. Potentiometer enables volume control....
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This circuit was designed in response to a request from my reader. What he asked for was a 1KHz IR transmitter circuit for some remote control application. I think this circuit may satisfy him. Any way this circuit can be used where ever a low power IR....
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With a matching antenna, the FM transmitter circuit shown here can transmit signals up to a range of 2 kilo meters. The transistor Q1 and Q2 forms a classic high sensitive preamplifier stage. The audio signal to be transmitted is coupled to the base of Q1....
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A high quality stereo amplifier circuit of 44 Watts (22 Watts per channel) using TDA 1554 IC. This is a powerful audio amplifier circuit for 2 channels....
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The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low....
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A very stable and simple FM transmitter circuit is given here. With a matching antenna, this transmitter can attain a range of around 200 meters. I assembled this transmitter few years and got very good results. Let us see how the circuit works. A condenser....
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The audio amplifier shown here is based on the TDA7240 IC from ST Microelectronics. The TDA 7240 is an integrated audio amplifier IC that can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in....
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The circuit shown here works from 24V DC and can flash two 24V bulbs alternatively. The circuit is nothing but an astable multivibrator operating at 1Hz and 50% duty cycle. The lamp to be flashed is connected in place of the collector resistor (Rc) of a....
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This lead acid battery charger circuit is designed in response to a request from Mr. Devdas. C. His requirement was a circuit to charge two 12V/7AH lead acid batteries in series. Anyway he did not mentioned the no of cells per each 12V battery. The no of....
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Here is the circuit diagram of a simple 24W mono amplifier using IC TDA1516. The TDA1516 is an integrated class B power amplifier in a 13 pin SIL package. The IC has many useful features such as short circuit protection, load dump protection, thermal....
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Power amplifier circuit diagram with schematics. This simple audio power amplifier circuit is designed for 25 watts output power using TDA 2009 IC -which has two channels (stereo),12.5 W each channel....
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Here is a very simple three transistor audio amplifier circuit that can deliver 250mW to a 8Ohm speaker. Complementary transistors BC337 and BC227 (Q3 and Q2) are used as the output pair. Transistor Q1 (BC 547) acts as the preamplifier. POT R5 can be used as....
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A simple Hi Fi amplifier circuit diagram with schematic for making audio amplifier,design using TDA 2616 IC, which is a stereo power amplifier, useful for radio,tape and television. Delivers 2*12 watts net 24 watts....
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TDA4935 is bipolar stereo amplifier IC that can be wired as a 2X15W stereo amplifier or a 30W mono BTL amplifier. The IC also features built in circuitry for over load protection and over temperature shut down. Here the IC is wired in stereo mode in order to....
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Here is a simple 3 band graphic equalizer circuit made of a single op amp IC LF351 (IC1) and few passive components. The component values of this circuit are not very critical and can be replaced with nearest values with a little loss on the performance.....
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Here is the circuit diagram of a simple 3 band graphic equalizer circuit using a single IC and few components. The IC used here is LF 351 which is a wide bandwidth single JFET operational amplifier. The high input impedance of the IC makes this circuit....
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Here is the circuit diagram of a simple 3 channel audio splitter based on the IC NE5532. NE5532 is a dual internally compensated low noise opamp from Fairchild semiconductors. It has a high small signal and power bandwidth, making it well suitable for high....
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Here is a simple 3 input mic mixer circuit using the popular uA 741 ICs. Four 741s are used here. IC1, IC2, IC3 are used as preamplifiers. They produce a gain of around 40 decibel to the individual input signals. The IC4 is wired as a summing amplifier to....
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The circuit given here is of a three input mic mixer cum preamplifier using the IC LM348. The LM348 is a high gain, internally compensated quad operational amplifier with a class AB output stage. The IC has very low input supply current drain (0. 6mA/ opamp)....
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Are you not familiar with the basics of electronics We have just opened an online store where 4 very good books on basic electronics have been kept for sale. You can read the reviews of these books and buy them as you wish. These books are being followed by....
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An audio power amplifier circuit for 3 watts stereo amplifier using max 7910 IC is explained below....
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I`m a bit of a newbie, but I love to experiment. I thought I would try to make a small guitar amplifier using some of the circuit designs posted here. I`m thinking of using this 30 Watt design (actually, the single 12VDC version mentioned in the comments....
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This is the circuit diagram of a 3A adjustable power supply using IC LM350K. LM350K is a very rugged voltage regulator IC with features like thermal regulation, short circuit protection etc. This circuit is designed as per the application notes in the data....
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A lot of electronic circuits in the domain of audio amplifiers are already been published here. This circuit is a little different because it is a four channel amplifier. Each channel of this amplifier can deliver an output of 15Watts into a 4 ohm speaker.....
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This is a very excellent 40W power amplifier design using TDA2030 IC and two transistors. The circuit employs only few components and does not require a dual power supply. The input signal is coupled to the non inverting input of TDA2030 through the DC....
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This is a simple 4 W fluorescent lamp driver circuit that can be operated from a 12 V supply. The first part of the circuit includes a NE555 timer IC wired as an astable multivibrator. The output pulses from the IC are amplified by the transistor Q1. The....
Most homes today have at least a few infrared remote controls, whether they be for the television, the video recorder, the stereo, etc. Despite that fact, who among us has not cursed the light that remained lit after we just sat down in a comfortable chair....
How often does it happen that you close down Windows and then forget to turn off the computer This circuit does that automatically. After Windows is shut down there is a click` a second later and the PC is disconnected from the mains. Surprisingly enough,....
The alarm may be used for a variety of applications, such as frost monitor, room temperature monitor, and so on. In the quiescent state, the circuit draws a current of only a few microamperes, so that, in theory at least, a 9 V dry battery (PP3, 6AM6,....
You can save on your electricity bills by switching to alternative sources of power. The photovoltaic module or solar panel described here is capable of delivering a power of 5 watts. At full sunlight, the solar panel outputs 16. 5V. It can deliver a current....
Normally home appliances are controlled by means of switches, sensors, etc. However, physical contact with switches may be dangerous if there is any shorting. The circuit described here requires no physical contact for operating the appliance. You just need....
This circuit can be built from readily available low-cost components, some of which may even be hiding in your junkbox! The indicated value of 22 for resistor R1 causes an average current of about 65 mA through infrared emitter D1. Because the IRED is....
You cannot beat the Chinese. The project described in this article is a ready-made item from a $2. 00 shop! And it is made in China! It is a wireless doorbell with a cost of about $10. 00. It is so cheap, you could not build it from components for $10. 00!....
As time goes by, microcontrollers become more powerful, cheaper, and smaller. A typical micro of the past could have had 40 pins and no internal memory. On the contrary, modern J-series PICs are made with 96K program memory and 28 pins. We can drive a lot of....
You need not be disappointed next time when your digital camera shows low battery indication during a picnic trip. Just plug this digital camera adaptor into the cigarette lighter outlet of your car and connect the camera to it. The adaptor will interface....
This 7-digit combination lock can be easily hard-wired for any combination that you choose. The circuit uses a 4-bit, divide-by-8 Johnson counter (IC1), ten push button switches and NPN transistor T1. At power-on, ` capacitor C2 connected to pin 15 of IC1....
This circuit features automatic exit and entry delays - an optional instant alarm zone - an optional intermittent siren output - and an automatic reset. By adding external relays you can immobilize the vehicle and flash the lights. The alarm is set by....
Here is one of the interesting 555 timer circuits to trick your friends while studying electronics in schools. Clap switch circuit is the local name of sound controlled flip flops. This sound controlled light can also be used as sound detection sensors. Flip....
The process of converting an analog voltage into an equivalent digital signal is known as Analog to Digital Conversion, abbreviated as ADC. An ADC is an electronic circuit which converts its analog input to corresponding binary value. The output depends up....
Astable Multivibrator can be designed by using 555 timer IC, Op Amps and also using transistors. The 555 IC provide accurate time delay from mille seconds to hours. The frequency of oscillation can be controlled manually by simple modification. This is a....
Transistor is a semiconductor device used for switching and amplification of weak signals. This article explains how a transistor work and the working of transistor as a switch. At present, transistors are applied in most of the electronic equipments for....
We can also take output from collector terminals of the transistors, such circuit is show below. To know the working of below circuit you must read How transistor acts as a switch ..
In binary phase shift keying (BPSK) modulation scheme, the phase of a carrier is changed in accordance with the digital pulse signals. BPSK modulator is basically a phase modulator. Here the transmitted signal is a sinusoid of fixed amplitude. It has one....
What is DAC Digital to analog converter (DAC) is used to get analog voltage corresponding to an input digital data. Data in binary digital form can be converted to corresponding analog form by using a R-2R ladder (binary weighted resistor) network and a....
Inverting amplifier is one of the most popular Operational Amplifier circuits. The output changes in such a way that tries to avoid saturation and counteract the change caused by the input. This makes the amplifier stable. The amplifier tries to resist....
Operational amplifier based triangular wave form generator is simple circuit that is widely used in function generators. Here is the circuit for Triangular wave generator using 741 op amp. We know that the integrator output waveform will be triangular if the....
Automatic water level controller circuit is a simple engineering project. It can automatically switch ON and OFF the domestic water pump set depending on the tank water level. You can implement this motor driver circuit at your home or college using less....
Binary Amplitude Shift Keying (BASK) or On Off Keying (OOK) is one of the digital modulation techniques in which the amplitude of carrier is switched according to the binary data. This digital modulation scheme is used to transmit digital data over optical....
Here we define 7 levels in thereservoir. The sensed values are connected to an encoder circuit. The encoder circuit consist of a 74148 IC, which is a 8 line to 3 line encoder. Next section is the HEX Display` which is a special type of 7 segment display. It....
Here I will show you an audio amplifier circuit that can be used for walkie talkies, low power transmitters, and packet radio receivers. A condenser mic audio amplifier gives good quality audio of 0. 5 watts at 3 volts. Here we are going to make use of BEL....
In this article we will be discussing about a home security alarm circuit. This is a LPG gas leakage sensor circuit that detects the outflow of LPG gas and alerts the user via audio and visual indications. The heart of this simple engineering project is a....
Monostable 555 timer multivibrator circuit (one shot monostable multivibrator) is a retriggerable mono shot pulse generator. The name Mono stable` indicates that it has only one stable state. The unstable state is called Quasi stable state`. The duration of....
This article gives the FM transmitter circuit schematics with necessary explanation. The main component used here is the VMR6512 IC which is a highly integrated FM audio signal (Hi-Fi Audio FM) transmitter chip. You can use this as FM radio transmitter for....
Summing amplifier or an adder is used to sum two signal voltages. Voltage adder circuit is a simple circuit that enables you to add several signals together. It has wide variety of applications in electronic circuits. For example, on a precision amplifier,....
Here we are going to discuss about a simple timer IC 555 project. The 555 timer IC can be used as an audio amplifierwithastable multivibrator configuration. It functions as to carry outpulse width modulation (PWM) of audio signal. Current(I) capacity of 555....
This is a very useful and simple circuit diagram for amplifying weak signal from a capacitive condenser microphone. You can use this circuit for sound sensing applications and some automatic robotic sensors. We have already posted an efficient audio....
How can we rotate a DC motor in clockwise and anti clockwise directions Or how can we rotate a motor in forward and reverse direction These are the popular question asked by many of the robotic beginners. DC Motor (control) driver circuits are the essential....%2Bwith%2Banimation%2Bsimulation%2Bcircuit.png "Johnson digital counter circuit diagram using D flip flop 7474 (3 bit/4 bit) with animation/ simulation")
The Johnson digital counter or Twisted Ring Counteris a synchronous shift register with feedback from the inverted output (Q`) of the last flip-flop. Q` of the last flip flop is connected back to the input D of the first flip-flop. This inversion of Q before.....png "Mobile cell phone detector (sniffer) circuit diagram: engineering and diploma project")
Here is a simple engineering project circuit of handy mobile cell phone detector (sniffer). This pocket-sizedmobile communication detector or sniffer can sense the existence of a mobile device. So it can be used to avoid the use of mobile phones in private....
How to create dual power supply unit using single battery for your lab prupose Dual voltage power supplies are required particularly for op amp experiments and some of the instrumentation amplifiers. Some low power audio pre amplifiers also uses dual voltage....
This is a simple 12V rechargeable smart battery charger circuit. You can use this best battery charger circuit as car battery chargers, Inverter battery charger, Emergency light battery charger etc. An automatic indicator alarm circuit also comes along with....%2BCircuit%2Bdiagram%2Busing%2BCD4047%2Band%2BIRFZ44%2Bpower%2BMOSFET.png "Simple low power Inverter Circuit (12V DC to 230V or 110V AC) diagram using CD4047 and IRFZ44 power MOSFET")
This simple low power dc to ac inverter (dc to ac converter) circuit converts 12V DC to 230V or 110V AC. By doing simple modification you can also convert 6V DC to 230V AC or 110V AC. It can be used as inverters for home needs to enable light loads (electric....
Water tank overflow liquid level sensor alarm circuit is a simple electronics project for school students. In the previous articles we had discussed about numeric water level indicator and water level controller circuit, but those circuits are much complex....
Here is a new audio power amplifier schematic built around TIP darlington pair transistors. You can use this circuit for home audio power amplifiers and car audio amplifiers. The TIP142 and TIP147 darlington pair transistors forms a push pull high power....%2Busing%2Bop%2Bamp%2B741%2Bic%2B.png "Zero Crossing Detector (ZCD): Comparator circuit using 741 op amp")
Zero crossing detector(ZCD) is a voltage comparator that switches the output between +Vsat and Vsat (Vsat: Saturation voltage almost equal to 14V) when the input crosses zero reference voltage. Then what is a comparator In simple words comparators are basic....
Here i-St@r comes with thesimplest mini audio amplifier circuitschematicusing LM386 low voltage audio power amplifier IC. This circuit is applicable to power medium sized speakers from a music player that can only drive earphones (lm386 headphone). The LM386....
How to measure water purity How to test water quality using a simple electronics project You can perform water purity measurement and water quality analysis using this water purity checker circuit. This circuit is built around a simple LDR (Light Depended....
Wien bridge oscillator is an audio frequency sine wave oscillator of high stability and simplicity. Before that let us see what is oscillator An oscillator is a circuit that produces periodic electric signals such as sine wave or square wave. The application.....png "Home security alarm system circuit diagram")
Have you ever thought aboutimplementing your own home security alarm systems It`s one of the simplest and interesting circuits for electronic beginners. Our new home security equipment uses aLDR (Light Depended Resistor) to detect security problems. Theft....
This article explains What is inverter And how can you construct your own simple low cost 12V to 220V inverter circuit. An inverter is nothing but a DC to AC converter. Inverters are very useful electronics products for compensating emergency power failure,....
Here is a simple PWM dc to ac voltage inverter circuit based on IC SG 3524. The SG3524 IC chips is a fixed frequency PWM (Pulse Width Modulation) voltage regulator control circuit, with indifferent outputs for single ended or push pull applications. The....
This is a simple 2N2222 transistor based radio FM transmitter circuit within the FCC (Federal Communications Commission) limit, that is no license is necessary for using thisstable FM transmitter circuit. What is an FM transmitter FM stands for Frequency....
This is the most simplest and single transistor FM wireless transmitter circuit that ever posted in CircuitsGallery. In telecommunication field, frequency modulation (FM) transmits information by changing the frequency of a carrier wave according to message....
This is a MOSFET transistor based power amplifier circuit that can be operated between +35V to -35V range. The input voltage is pre filtered and pre amplified before applying to the MOSFET switch. The pre audio amplifier is a differential amplifier section....
We know that astable multivibrator is simply an oscillator circuit that produces continuous pulses without the help of any external triggering. The oscillation frequency and time period can be manually controlled through simple modification of resistors and....
I have posted wide varieties ofsmall electronic projects onwater level sensor in Circuits Gallery. This is another project for school students to detect the water level inside a water tank or any other water reservoir. We can call this as a liquid level....
Voltage fluctuation is a serious issue in every home. Due to some reasons our supply voltage may rise above 110V or 230V. Flow of this high electricity may lead to the damage of our home electrical devices. Have you thought how electrical protection is....
Digital counters have several applications in electronics circuits. Counters in digital electronics are used at different situations. Here we are going to deliver the idea of aRing counter circuit, which is a register counter. Working animation and circuit....
In this section we would like to introduce you a transistor oscillator circuit, called as RC Phase shift Oscillator. First of all we need to know what is an oscillator. An oscillator is an electronic circuit which acts as a sine wave generator. The only....
Intercom or Inter communication circuit is a two directional communication system. It provides a reliable communication line and is extremely easy to implement. The circuit is prepared by an amplifier, two switches and two loudspeakers. We can extend this....
Zener diode regulator is a basic electronic circuit which is very useful for those interested in hobby circuits. This circuit is used for obtaining a regulated voltageat the output which can be used for biasing other circuit elements. Now how to use zener....
At many situations we need to display the amount of battery charge through some kind of indication methods like LED dot display or LED bar display. Here CG comes with a battery charge indicator circuit using LED dot display. This battery power level....
Here we are going to discuss about an Asynchronous 4 Bit Binary Up Counter, a circuit made up of several J-K flip-flops cascaded to generate four bits counting sequence. An up counter is basically a digital counting circuit which counts up in an incremental....
How to change the brightness of aLED Whether led lights are dimmable Is it possible to adjust the brightness of LEDs LED is basically a diode, when the forward voltage exceeds 0. 7 volt, it starts to glow, and if the forward voltage is less than 0. 7 volt,....
How to build a voltmeter for DC voltage measurements without using multimeter testing This is a simple digital voltmeter circuit that can measure voltages from 0V to 9V. The main part of this circuit is a dot bar display driver IC LM3914. Input voltage....
Solar energy has now become a popular alternative for the production of electricity. Here is a green energy project for school students on how to make solar lamps for your home. The main component of this simple solar lamp circuit is a small solar panel and....
This is a simple DIY charge controller schematic posted in response to a request by one of our readerson our facebook page. The main component of this auto battery charger circuit is a 555 timer which compares the voltage in the battery. It turns ON the....
Here is a hobby circuit of a multi channel remote control system, by which you can control 8 different appliances. The main sections of this multi channel remote control circuit are the RF receiver and transmitter. By using this circuit we can control 8....
Have you seen Audi, Lexus or Ford rain sensing wipers and wondered how they work in these vehicles They are handled by sensors at the center of the windscreen which detects rain water and turns on the wiper motor. Here is the working of rain sensitive wipers....
When ever you need to get an alarm or intimation after ten minutes, the circuit shown below can be used. The circuit is nothing but a monostable multivibrator based on IC NE 555. When ever you press the reset push button the green LED D1 glows after 10....
Hi-fi 100W mosfet power amplifier circuit . Operates from 45v dual supply. 100W to 8 ohm speaker, 160W to 4 ohm speaker, low distortion....
Reliable 10A adjustable voltage regulator based on MSK5012. 1.3 to 30V output voltage range. Low ripple and high efficiency....
Here is a simple and effective circuit for driving florescent lamps from a 12 V supply. The circuit is nothing but consists of an oscillator, a MOSFET switch and a step-up transformer for driving the florescent lamp. The IC1 TLC 555 is wired as an astable....
This voltage regulator circuit can deliver up to 3A at 12V output voltage. The circuit can be employed on occasions when a current of more that 3A is demanded for regulator. IC regulators of such high current rating are pretty hard to find. The transformer....
Here is a simple yet powerful circuit that can be used for flashing 12V lamps especially that is used on automobiles. The flashing circuit is based on transistor Q1(BC557) and MOSFET Q2 (IRF530) where the Q2 provides the necessary drive for the lamp. Any....
A simple 12V to 24V dc dc converter circuit with diagram built around LM324. This boost converter with schematic can provide up to 800mA output current and a steady 24V DC....
This 1. 3V power supply can be used as replacement for the 1. 3V Mercury Cell in any circuit. When the input 5V is given to the circuit, the voltage drop across zener diode D1 will be around 2V. The diode D2 will drop a 0. 7 V from the 2V volt and the....
15 Watts Class B Audio amplifier circuit. This 15W amplifier circuit is designed using a dual op-amp LM833. Diagram and Schematics are shown. Potentiometer enables volume control....
This circuit was designed in response to a request from my reader. What he asked for was a 1KHz IR transmitter circuit for some remote control application. I think this circuit may satisfy him. Any way this circuit can be used where ever a low power IR....
With a matching antenna, the FM transmitter circuit shown here can transmit signals up to a range of 2 kilo meters. The transistor Q1 and Q2 forms a classic high sensitive preamplifier stage. The audio signal to be transmitted is coupled to the base of Q1....
A high quality stereo amplifier circuit of 44 Watts (22 Watts per channel) using TDA 1554 IC. This is a powerful audio amplifier circuit for 2 channels....
The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low....
A very stable and simple FM transmitter circuit is given here. With a matching antenna, this transmitter can attain a range of around 200 meters. I assembled this transmitter few years and got very good results. Let us see how the circuit works. A condenser....
The audio amplifier shown here is based on the TDA7240 IC from ST Microelectronics. The TDA 7240 is an integrated audio amplifier IC that can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in....
The circuit shown here works from 24V DC and can flash two 24V bulbs alternatively. The circuit is nothing but an astable multivibrator operating at 1Hz and 50% duty cycle. The lamp to be flashed is connected in place of the collector resistor (Rc) of a....
This lead acid battery charger circuit is designed in response to a request from Mr. Devdas. C. His requirement was a circuit to charge two 12V/7AH lead acid batteries in series. Anyway he did not mentioned the no of cells per each 12V battery. The no of....
Here is the circuit diagram of a simple 24W mono amplifier using IC TDA1516. The TDA1516 is an integrated class B power amplifier in a 13 pin SIL package. The IC has many useful features such as short circuit protection, load dump protection, thermal....
Power amplifier circuit diagram with schematics. This simple audio power amplifier circuit is designed for 25 watts output power using TDA 2009 IC -which has two channels (stereo),12.5 W each channel....
Here is a very simple three transistor audio amplifier circuit that can deliver 250mW to a 8Ohm speaker. Complementary transistors BC337 and BC227 (Q3 and Q2) are used as the output pair. Transistor Q1 (BC 547) acts as the preamplifier. POT R5 can be used as....
A simple Hi Fi amplifier circuit diagram with schematic for making audio amplifier,design using TDA 2616 IC, which is a stereo power amplifier, useful for radio,tape and television. Delivers 2*12 watts net 24 watts....
TDA4935 is bipolar stereo amplifier IC that can be wired as a 2X15W stereo amplifier or a 30W mono BTL amplifier. The IC also features built in circuitry for over load protection and over temperature shut down. Here the IC is wired in stereo mode in order to....
Here is a simple 3 band graphic equalizer circuit made of a single op amp IC LF351 (IC1) and few passive components. The component values of this circuit are not very critical and can be replaced with nearest values with a little loss on the performance.....
Here is the circuit diagram of a simple 3 band graphic equalizer circuit using a single IC and few components. The IC used here is LF 351 which is a wide bandwidth single JFET operational amplifier. The high input impedance of the IC makes this circuit....
Here is the circuit diagram of a simple 3 channel audio splitter based on the IC NE5532. NE5532 is a dual internally compensated low noise opamp from Fairchild semiconductors. It has a high small signal and power bandwidth, making it well suitable for high....
Here is a simple 3 input mic mixer circuit using the popular uA 741 ICs. Four 741s are used here. IC1, IC2, IC3 are used as preamplifiers. They produce a gain of around 40 decibel to the individual input signals. The IC4 is wired as a summing amplifier to....
The circuit given here is of a three input mic mixer cum preamplifier using the IC LM348. The LM348 is a high gain, internally compensated quad operational amplifier with a class AB output stage. The IC has very low input supply current drain (0. 6mA/ opamp)....
Are you not familiar with the basics of electronics We have just opened an online store where 4 very good books on basic electronics have been kept for sale. You can read the reviews of these books and buy them as you wish. These books are being followed by....
An audio power amplifier circuit for 3 watts stereo amplifier using max 7910 IC is explained below....
I`m a bit of a newbie, but I love to experiment. I thought I would try to make a small guitar amplifier using some of the circuit designs posted here. I`m thinking of using this 30 Watt design (actually, the single 12VDC version mentioned in the comments....
This is the circuit diagram of a 3A adjustable power supply using IC LM350K. LM350K is a very rugged voltage regulator IC with features like thermal regulation, short circuit protection etc. This circuit is designed as per the application notes in the data....
A lot of electronic circuits in the domain of audio amplifiers are already been published here. This circuit is a little different because it is a four channel amplifier. Each channel of this amplifier can deliver an output of 15Watts into a 4 ohm speaker.....
This is a very excellent 40W power amplifier design using TDA2030 IC and two transistors. The circuit employs only few components and does not require a dual power supply. The input signal is coupled to the non inverting input of TDA2030 through the DC....
This is a simple 4 W fluorescent lamp driver circuit that can be operated from a 12 V supply. The first part of the circuit includes a NE555 timer IC wired as an astable multivibrator. The output pulses from the IC are amplified by the transistor Q1. The....
