Top Circuits Page 166
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Here is a project of a 555 touch alarm circuit with UM66 melody IC. The circuit will produce a melodious alarm sound for a set time period when someone touches the metal plate / touch plate shown in the schematic....
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This is a very simple transistor tester circuit the circuit can be used to test NPN and PNP transistors. The voltage source is a 6V power supply which is 230V AC to 6V step down transformer. It is essential to put the transistor leads in right direction like....
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Here`s a simple schematic of a TV transmitter circuit or video transmitter circuit which is able to broadcast on VHF between 60 to 200 MHz. The input video can be from any CCD camera and VCR. The output power of this VHF transmitter circuit is 80mW and by....
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This UHF antenna amplifier circuit or UHF antenna booster circuit can be used to amplify or boost the signal of UHF band from 400 MHz to 850 MHz. This circuit is using only single transistor and provides 15 db amplification. For best results keep all the....
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This is a project of a mini USB car charger circuit. The circuit is very simple to build using only three components. Heart of the circuit is a LM78M05 IC which is a 5V positive voltage regulator IC. This IC has many built in featuers like thermal overload....
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Portable battery powered USB charger circuit or schematic using IC LM7805. The circuit require only few components. ....
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Here is the schematic of a water level alarm circuit. The circuit will work as a water level sensor and will give a melodious alarm sound when the two probes in the circuit will detect water. You can use this water level indicator circuit to detect the level....
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You can use this water level alarm circuit anywhere as a water level indicator to detect the desired level of water for example in tanks, swimming pools or at any place where you store water. The circuit is build around a 555 timer IC which is a famous and....
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This is a simple water level indicator circuit or water level sensor circuit. The circuit is very easy to build and contains only three PNP transistors and some other components. This is a very useful circuit to detect the level of water in the tank. The....
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Here is a schematic of a simple water or liquid level sensor relay switch circuit, which can be used to switch on or off electronic appliances at the desired level of water. The circuit is ideal for automatically switch off the water pump when your water....
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RF detector circuit, RF amplifier circuit, auto gain control circuit (AGC) etc is already built inside the IC due to which you can easily build a high quality and sensitive am receiver using this IC. The ZN415E IC is an advance version of ZN414 IC, the....
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Brand N-Ch VFET P/N: 2SJ28 from Sony for TA-N88 Class D Amplifier, great variety of active, discrete, passive components, RF, Obsolete Components available at factory price....
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One of my friends asked me if I could design a circuit for him to be able to remotely power up a server. He has 2 servers and he didn`t want to keep them both on whilst he travelled. He wanted to be able to turn on a server when he needed it. He has one....
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This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range. It can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a....
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The following circuit is an electronic approximation of the gold leaf electroscope`, except that this electrometer indicates polarity as well as electric field magnitude. It is incredibly sensitive! It will detect a television or an electrostatically charged....
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This circuit uses a small AC current transformer from Magnetek to produce an isolated voltage proportional to the AC current in the primary winding. The transformer contains a single turn primary with a low 0. 001-ohm resistance. It can easily handle 30 amps....
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If you need about 12, 000 volts DC for an ion generator this circuit might be the ticket. It draws power from the 120vac power line but it uses a small 6KV camera flash trigger coil. The output signal is isolated from the power line. Although the circuit can....
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Sealed-lead-acid batteries, which find wide use in power-electronics products, such as UPS (uninterruptible-power supplies), inverters, and emergency lamps, supply power to the load whenever utility power is unavailable. When you restore utility power, a....
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This circuit is connected to your motorcycle. It`s tapped into a circuit thats only powered with the key "ON". If you turn the bike off with the kill-switch and leave the key on, as you know, the headlight will stay on and quickly drain the battery. With....
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A beep or metronome-like click and/or a visible flash, will beat the one-second time and can be useful in many applications in which some sort of time-delay counting in seconds is desirable. The circuit is formed by a CMos 4024 counter/divider chip and 3....
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The 15V dc supply is obtained from a nominal 230/24V center tapped ac transformer (T1) and a full wave rectifier (D5 & D6): Zener diode D4 was added to clamp the dc voltage to 15V maximum. Triacs D7, D8 and D9 are insulated from the control circuitry by....
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The circuit below was developed to guard the fish pond. In this case to prevent that the pump sucks just air when the waterlevel get below the pump. When the waterfilters get saturated and dirty, the water level behind the filter gets to an unacceptable....
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Do you know how infrared motion detector alarm Whenever someone comes in the infra-red zone. Infrared motion sensor, which detects moving human body. The alarm will sound automatically. The detection zone coverage is 80 degrees horizontally to 8 meters....
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This is a simple single zone home Alarms Systems circuit. Its features include Entry delays, a timed Siren Cut-Off and and automatic Exit. It`s designed to be used with the usual types of normally-closed input devices such as - - foil tape - micro switches -....
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The circuit can also be triggered by logic ICs(TTL/CMOS) using proper interfacing method. I usually use another relay that serve as the trigger button when interfacing ICs to latching relay circuit. ..
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This is a simplified design using a up/down counter IC, 74192. It is a versatile logic IC that has a separate pins for up and down count. Also, an RS latch is used for the indicator of the counter number. ..
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This is one of the common circuit blocks being used both in digital and analog electronics. Its output is dependent on the relationship of its two input pins. One of the inputs is set to give the reference voltage while the other one is commonly connected to....
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Many published circuits that flash LEDs need 3 volts or more. This circuit uses only a single inexpensive C-MOS IC and flashes the LED for a full year on a single 1. 5 volt AA alkaline battery cell. The circuit uses a charge pump technique to provide the LED....
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Many battery powered devices use two AA alkaline cells. Often you will not know when it is time to replace the batteries until the device powered by them actually stops operating. The hobby circuit below can be connected to a 3v battery, to give you some....
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This simple circuit uses NAND Gates to alternately flash two led`s. The two 47uF capacitors determine the flash frequency. It is a good idea to use a decoupling capacitor across the power supply. I made this circuit using the components shown and it worked....
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The circuit uses a 555 timer oscillator to supply clock pulses of a variable frequency to the 4017 decade counter. The decade counter only needs to have three outputs so the fourth output goes into the reset pin to start the cycle all over again. The central....
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This is probably the simplest idea to generate flashing light from an LED using AC. The circuit is relatively the simple way of flashing one or more LEDs from a high voltage DC obtained from Mains. This can be used as a Mains indicator or Mock flasher. The....
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This circuit calls more Free Running Multivibrator work resemble Flip Flop. Which encourage itself repeatedly. The Q1 and Q2 be Transistor PNP be usable general (2N3906, 2N2907, etc. ) The R1 and R2 limit current that flow through LED the bilateral. If....
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This circuit uses the TLC555CP timer I. C. to flash an LED roughly twice every second. This particular type of 555 timer will run off only 3 volts so two 1. 5 volt cells can be used. With "AA" cells, you can expect a battery life of up to 6 months. With....
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Do not try this circuit unless you have good knowledge about electronic devices. This circuit is connected to main power source (220V) and can give you a high electrical shock ..
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This simple LED torch is driven by a 2-transistor blocking oscillator which steps up the voltage from a 1. 5V cell. It relies on the inherent current limiting of the 150 µH choke to protect the white LED from over-drive. With a 9V zener diode in place of the....
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In addition to providing an accurate input current limit, the LT1618 can also be used to provide a regulated output current for current-source applications. White LED drivers are one such application for which the LT1618 is ideally suited. With an input....
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In the circuit diagram for the Joule Thief, the common point of the toroid is the connection at the top of the hand-wound ferrite toroid, in the upper right of the diagram. This goes to the positive end of the battery. The other two wires from the toroid go....
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This is a simple LED torch circuit based on IC MAX660 from MAXIM semiconductors. The MAX 660 is a CMOS type monolithic type voltage converter IC. The IC can easily drive three extra bright white LEDs. The LEDs are connected in parallel to the output pin 8 of....
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This circuit will flash a bright red LED (5000 mcd) as an attention getting device or fake car alarm. Component values are not critical and other transistors may be used. Flash duration is determined by R2 and C1 and is approximately 3 time constants....
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In addition to providing an accurate input current limit, the LT1618 can also be used to provide a regulated output current for current-source applications. ..
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This circuit drives as many as four white LEDs in parallel from a 3. 3V source, and adjusts the total LED current from 1mA to 106mA, in 64 steps of 1dB each. The circuit of Figure 1 is designed for portable-power applications that require white LEDs with....
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Many consumer products using white light LEDs for illumination and backlighting provide gradual LED illumination at turnon and turnoff. This gradual illumination is usually achieved with the aid of a Microprocessor that provides PWM dimming control. This....
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Can be directly connected to CD players, tuners and tape recorders. Simply add a 10K Log potentiometer (dual gang for stereo) and a switch to cope with the various sources you need. A correct grounding is very important to eliminate hum and ground loops.....
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This is an 250mW RF power amplifier project. This circuit is designed to amplify the output of about 7mW wide band FM transmitters to a final level of about 250mW. This electronic circuit is a simple 2-transistor VHF power amplifier, with about 16dB gain,....
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the decision of designing a 9V powered Headphone Amplifier was finally taken. The main requirement was to power the circuit by means of a common, PP3 (transistor radio) alkaline battery. The appearance of the 5534 low-noise op-amp at a reasonable price was....
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The FM Remote Control Receiver` (available on this website in Infra-red circuits section) has a connector where an analogue output is made available. To make a simple intercom or P. A. system the associated transmitter needs a microphone pre-amplifier that....
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A popular project among microcontroller aficionados is to build a radio-controlled clock. Tiny receiver boards are available, with a pre-adjusted ferrite antenna, that receive and demodula..
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This is a great audio amplifier circuit based on single power IC TDA7294. TDA7294 is intended for use as a high quality audio class AB amplifier in hi-fi applications. It has very low noise ..
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The modem off indicator is intended especially for serious Internet surfers. It will be seen that the circuit of the indicator cannot be much simpler, or there might be nothing left. In spite of its simplicity, it may prove to be a cost-saving device, since....
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It can be used as part of intercoms, walkie-talkies, low-power transmitters, and packet radio receivers. Transistors T1 and T2 form the mic preamplifier. Resistor R1 provi..
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The common characteristic of all of the previous low power FM transmitters I`ve built over the decades, is that their operating frequency is determined by an LC resonant circuit. ..
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However effective a domestic alarm system may be, it`s invariably better if it never goes off, and the best way to ensure this is to make potential burglars think the premises are occupied. Indeed, unless you own old masters or objects of great value likely....
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The cause may be dry solder joints, defective LEDs etc. , but also a flat battery (perhaps due to stuck key). The human eye is unable to perceive infra-red light. By contrast, an ordinary photo transistor like the BP103 has no problems working in the....
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Easy to build high-quality PLL FM transmitter with typical output power of 5 W and no-tune design. The transmitter includes RDS/SCA input and Audio/MPX input with optional pre-emphasis. It can be used with or without stereo encoder. Tuning over the FM band....
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The circuit presented here illustrates the fact that in spite of all kinds of new component and technology, it is still possible to design useful, and interesting, circuits. The circuit is based on two well-established transistors, a Type BF256C and a BF494.....
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Here is a simple circuit for a one transistor Audion type radio powered by a 1. 5 V battery. It employs a set of standard low-impedance headphones with the headphone socket wired so that the two sides are connected in series thus giving an impedance of 64 ©.....
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The signal from a microphone is two weak for a standard line input. This low-noise DC-coupled microphone amplifier provides a solution for anyone who wants to connect a microphone to his or her hi- installation. As can be seen from the schematic diagram, a....
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STK4038 bassed 60 watt audio amplifier circuit project and explanation Using the STK4038X audio amplifier IC, can be designed a very simple high power and efficiency audio power amplifier. This circuit is manufactured by Sanyo Corporation and will provide a....
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This electronic project stereo amp is based on the STK415-090-E class H audio power amplifier hybrid IC that features a built-in power supply switching circuit. This STK415-090-E class H audio power amplifier provides high efficiency audio power....
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The orientation of the camera at launch is looking out the side of the rocket and during descent on the parachute, it is looking down. To allow the camera to look down during lift off, an external mirror can be optionally added. Located in the nose cone of....
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This 3V FM transmitter Circuit is about the simplest and best basal transmitter to body and accept a advantageous transmitting range. It is decidedly able admitting its baby basic calculation and 3V operating voltage. It will calmly access over three floors....
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Nowadays the most commonly available headphones have an impedance of 2 G— 32 ©, this relatively low value makes them unsuitable for such a design. However, with a bit of crafty transformation these headphones can be used in just such a design. To adapt them,....
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The output frequency alternates between about 2100 Hz and 2200 Hz. This is a very distinctive test signal that is easily distinguished from any other signals that may be present. ..
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About a do-it-yourself alarm arrangement body with PIC18F452. It`s a abundant amusement activity although the schematic is actual complicated. This activity uses three capital accessories to actualize the claimed alarm system. The IR Ambit sensor gives....
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A stereo power amp designed for use in portable players and radios. A 3V supply can be used to drive headphones providing 20mW in..
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The wireless transmitter ambit congenital about transistor T1 (BF494) is a basal low-power variable-frequency VHF oscillator. A varicap diode ambit is included to change the abundance of the fm transmitter and to accommodate abundance accentuation by audio....
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This wireless headphones transmitter assures a affection accession over 2 meters. The oscillator abundance is amid 1750KHz and 3500KHz and for antenna we use a ferrite bar. IC1 amplifies the audio arresting and TC1 is a buffer. D1 signals that the....
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The ambit of frequencies for the FM advertisement bandage is 90MHz (MHz = Megahertz or 90 actor cycles per second). Because the FM microphone has a capricious acquainted circuit, it can be acquainted to a quiet atom on your bounded FM advertisement bandage....
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This FM transmitter circuit uses four radio abundance stages: a VHF oscillator congenital about transistor BF494 (T1), a preamplifier congenital about transistor BF200 (T2), a disciplinarian congenital about transistor 2N2219 (T3) and a ability amplifier....
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This is an UHF bandage TV antenna preamplifier circuit With 15dB accretion to body easily. It is formed based on BF180 UHF Transistor. The aboriginal date is an bandage canyon clarify complete by the C1, CV1, L1, L4, C7 and C3, the additional date is a....
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This accomplishing is acclimatized to rebroadcast the achievement of a CD player, television receiver, or radio receiver. I use it so that I can move about the abode and accept to my admired programs after advancing others. Within and the house, I....
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I accept acclimated a brace of BC548 transistors in this circuit. Although not carefully RF transistors, they still accord acceptable results. I accept acclimated an ECM Mic admit from Maplin Electronics, adjustment cipher FS43W. It is a two terminal ECM,....
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This Fm rf ability amplifier has 2 transistors from Philips : BLV 10 and BLW 87. The 2 rf transistors assignment in chic C and this fm amplifier has a absolute accretion of 21dB ( 100 X ) and ability 55 65%. One low canyon clarify with 9 apparatus ensures....
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Here you got it! 300 W rf authentic ability for fm transmission. 300 W radio ability amplifier for accomplished 88 108 MHz ! This fm amplifier has 2 TP9383 abundant to bear up to 300W. ..
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The important allotment of the circuit is formed of the Colpitts blazon oscillator. C3, C4, C5, C6, CD1-CD2 and L1 determines the frequency. BF982 and bifold aboideau MOSFET are alive genitalia in oscillator. When the ascribe impedance of the MOSFET aboideau....
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You may admit abounding of the date circuits - as they are agnate to those acclimated in some of my added projects. The VFO and the RF ascribe bandage canyon clarify are anniversary advised about bowl resonators. These are acceptable difficult to locate.....
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Servos became valuable products for any variety of plans, like robotics, automation or only remotely controlling some thing, for example model vehicle steering. They`re reasonably low-priced and also simple to have hold of, however controlling them can be a....
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The 60Watt RF (Radio Frequency) Amplifier is simple all solid accompaniment ambit application ability mosfet IRF840. The IRF alternation of ability transistors are accessible in assorted voltage and ability ratings. A distinct IRF840 can handle best ability....
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This simple counter can be used to count pulses, as the basis for a customer counter (like you see at the doors of some stores), or for anything else that may be counted. The circuit accepts any TTL compatible logic signal, and can be expanded easily ..
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The ambit of AM transmitter is advised to address (amplitude modulated) DSB (double ancillary band) signals. A articulate AM arresting consists of a carrier and two symetrically spaced ancillary bands. The two ancillary bands accept the aforementioned....
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It`s a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn....
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The circuit was meant to be powered by a power supply, which is why there is no transformer, rectifier, or filter capacitors on the schematic. There is no reason why you cannot add these. To use the circuit, hook it up to a power supply/plug it in. Then,....
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Thanks to the fully complementary PNP/NPN output configuration the TDA7383 allows a rail to rail output voltage swing with no need of bootstrap capacitors. The extremely reduced components count allows very compact sets. The on-board clipping detector....
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It is good idea to put this circuit in a box and mark/write each LED with number 1 to 6. Now, when switch S1 is pushed momentarily, any one of the 6 LEDs will glow. The Number marked for glowing LED becomes dice`s output. Every time S1 is released, new LED....
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This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just....
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This ambit is a simple two transistor (2N2222) mini FM transmitter. No authorization is appropriate for this transmitter according to FCC regulations apropos wireless microphones. If powered by a 9 volt array and acclimated with an antenna no best than 12....
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The affection of the ability accumulation is a Tamura 3FD-410 5V bifold primary/dual accessory transformer. These are accessible from DigiKey. com for reasonable prices. Normally, the transformer`s primary windings would be affiliated in alternation for....
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The circuitis a simple one transistor amplifier with amplification of about 30-40 dB (depends on transitor, temperature and voltage). The dynamic mic input is just a simple one transistor amplifier circuit with nothing special in it. LED D1 is inthe....
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When the water is empty the wires in the tank are open circuited and the 180K resistors pulls the switch low hence opening the switch and LEDs are OFF. As the water starts filling up, first the wire in the tank connected to S1 and the + supply are shorted by....
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This circuit can be used to monitor the voltage level of a car battery. When the battery voltage is 11. 5V or less the transistor Q1 is on and D1 glowing. When LED battery voltage is between 11. 5 to 13. 5 V, the transistor Q2 is on and the glowing LED D2.....
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This circuit inverter converts 12V DC battery to AC 22oV as the replacement of home energy. The inverter can be used for small electronic devices such as lamps, radio, phone charger, disc player, etc. The inverter circuit is a central component, the CMOS....
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Explore power amplifier integrated circuit from National Semiconductor LM4780. What`s so special Well, first of all - a very low harmonic distortion. In general, manufacturers indicate the maximum power of his ingenious craft regularly with the harmonic....
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This circuit will amplify voice audio in the range of 50 to 10, 000 cycles with little distortion, and have the ability to drive a low impedance load to 16 ohms. The circuit will run from 6 to 15 vdc and give about 20 dB of gain. To build an inexpensive....
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The circuit was meant to be powered by a power supply, which is why there is no transformer, rectifier, or filter capacitors on the schematic. There is no reason why you cannot add these. To use the circuit, hook it up to a power supply/plug it in. Then,....
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The LM380 is a power audio amplifier for consumer applications. In order to hold system cost to a minimum, gain is internally fixed at 34 dB. A unique input stage allows ground referenced input signals. The output automatically self-centers to one-half the....
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The MAX2605, MAX2609 are compact, high performance intermediate frequency (IF) voltage-controlled oscillator (VCO) designed specifically for demanding portable wireless communication systems. They combine monolithic construction with low noise, low operating....
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This simple amplifier is ideal for adding a headphone jack to equipment that lacks this feature. The Headphone Buffer circuit board is small enough (1. 2" X 1. 4") to squeeze into even the smallest spaces and power requirements are so low that existing....
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This inverter circuit can offer a really stable 230V Output Voltage. Frequency of operation is decided by a VR1 and is generally set to 60 Hz. varied off the shelf transformers can be used. Or Custom wind your own for best results. additional MosFets can....
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The LM3875 is an audio amplifier for high power output capable of delivering 56W of continuous average power to a load 8. The performance of the LM3875, utilizing its maximum instantaneous auto temperature ( ° Ke) (Spike ) protection circuitry, places it in....
Here is a project of a 555 touch alarm circuit with UM66 melody IC. The circuit will produce a melodious alarm sound for a set time period when someone touches the metal plate / touch plate shown in the schematic....
This is a very simple transistor tester circuit the circuit can be used to test NPN and PNP transistors. The voltage source is a 6V power supply which is 230V AC to 6V step down transformer. It is essential to put the transistor leads in right direction like....
Here`s a simple schematic of a TV transmitter circuit or video transmitter circuit which is able to broadcast on VHF between 60 to 200 MHz. The input video can be from any CCD camera and VCR. The output power of this VHF transmitter circuit is 80mW and by....
This UHF antenna amplifier circuit or UHF antenna booster circuit can be used to amplify or boost the signal of UHF band from 400 MHz to 850 MHz. This circuit is using only single transistor and provides 15 db amplification. For best results keep all the....
This is a project of a mini USB car charger circuit. The circuit is very simple to build using only three components. Heart of the circuit is a LM78M05 IC which is a 5V positive voltage regulator IC. This IC has many built in featuers like thermal overload....
Portable battery powered USB charger circuit or schematic using IC LM7805. The circuit require only few components. ....
Here is the schematic of a water level alarm circuit. The circuit will work as a water level sensor and will give a melodious alarm sound when the two probes in the circuit will detect water. You can use this water level indicator circuit to detect the level....
You can use this water level alarm circuit anywhere as a water level indicator to detect the desired level of water for example in tanks, swimming pools or at any place where you store water. The circuit is build around a 555 timer IC which is a famous and....
This is a simple water level indicator circuit or water level sensor circuit. The circuit is very easy to build and contains only three PNP transistors and some other components. This is a very useful circuit to detect the level of water in the tank. The....
Here is a schematic of a simple water or liquid level sensor relay switch circuit, which can be used to switch on or off electronic appliances at the desired level of water. The circuit is ideal for automatically switch off the water pump when your water....
RF detector circuit, RF amplifier circuit, auto gain control circuit (AGC) etc is already built inside the IC due to which you can easily build a high quality and sensitive am receiver using this IC. The ZN415E IC is an advance version of ZN414 IC, the....
Brand N-Ch VFET P/N: 2SJ28 from Sony for TA-N88 Class D Amplifier, great variety of active, discrete, passive components, RF, Obsolete Components available at factory price....
One of my friends asked me if I could design a circuit for him to be able to remotely power up a server. He has 2 servers and he didn`t want to keep them both on whilst he travelled. He wanted to be able to turn on a server when he needed it. He has one....
This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range. It can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a....
The following circuit is an electronic approximation of the gold leaf electroscope`, except that this electrometer indicates polarity as well as electric field magnitude. It is incredibly sensitive! It will detect a television or an electrostatically charged....
This circuit uses a small AC current transformer from Magnetek to produce an isolated voltage proportional to the AC current in the primary winding. The transformer contains a single turn primary with a low 0. 001-ohm resistance. It can easily handle 30 amps....
If you need about 12, 000 volts DC for an ion generator this circuit might be the ticket. It draws power from the 120vac power line but it uses a small 6KV camera flash trigger coil. The output signal is isolated from the power line. Although the circuit can.....jpg "mosfet prevents battery damage")
Sealed-lead-acid batteries, which find wide use in power-electronics products, such as UPS (uninterruptible-power supplies), inverters, and emergency lamps, supply power to the load whenever utility power is unavailable. When you restore utility power, a....
This circuit is connected to your motorcycle. It`s tapped into a circuit thats only powered with the key "ON". If you turn the bike off with the kill-switch and leave the key on, as you know, the headlight will stay on and quickly drain the battery. With....
A beep or metronome-like click and/or a visible flash, will beat the one-second time and can be useful in many applications in which some sort of time-delay counting in seconds is desirable. The circuit is formed by a CMos 4024 counter/divider chip and 3....
The 15V dc supply is obtained from a nominal 230/24V center tapped ac transformer (T1) and a full wave rectifier (D5 & D6): Zener diode D4 was added to clamp the dc voltage to 15V maximum. Triacs D7, D8 and D9 are insulated from the control circuitry by....
The circuit below was developed to guard the fish pond. In this case to prevent that the pump sucks just air when the waterlevel get below the pump. When the waterfilters get saturated and dirty, the water level behind the filter gets to an unacceptable....
Do you know how infrared motion detector alarm Whenever someone comes in the infra-red zone. Infrared motion sensor, which detects moving human body. The alarm will sound automatically. The detection zone coverage is 80 degrees horizontally to 8 meters....
This is a simple single zone home Alarms Systems circuit. Its features include Entry delays, a timed Siren Cut-Off and and automatic Exit. It`s designed to be used with the usual types of normally-closed input devices such as - - foil tape - micro switches -....
The circuit can also be triggered by logic ICs(TTL/CMOS) using proper interfacing method. I usually use another relay that serve as the trigger button when interfacing ICs to latching relay circuit. ..
This is a simplified design using a up/down counter IC, 74192. It is a versatile logic IC that has a separate pins for up and down count. Also, an RS latch is used for the indicator of the counter number. ..
This is one of the common circuit blocks being used both in digital and analog electronics. Its output is dependent on the relationship of its two input pins. One of the inputs is set to give the reference voltage while the other one is commonly connected to....
Many published circuits that flash LEDs need 3 volts or more. This circuit uses only a single inexpensive C-MOS IC and flashes the LED for a full year on a single 1. 5 volt AA alkaline battery cell. The circuit uses a charge pump technique to provide the LED....
Many battery powered devices use two AA alkaline cells. Often you will not know when it is time to replace the batteries until the device powered by them actually stops operating. The hobby circuit below can be connected to a 3v battery, to give you some....
This simple circuit uses NAND Gates to alternately flash two led`s. The two 47uF capacitors determine the flash frequency. It is a good idea to use a decoupling capacitor across the power supply. I made this circuit using the components shown and it worked....
The circuit uses a 555 timer oscillator to supply clock pulses of a variable frequency to the 4017 decade counter. The decade counter only needs to have three outputs so the fourth output goes into the reset pin to start the cycle all over again. The central....
This is probably the simplest idea to generate flashing light from an LED using AC. The circuit is relatively the simple way of flashing one or more LEDs from a high voltage DC obtained from Mains. This can be used as a Mains indicator or Mock flasher. The....
This circuit calls more Free Running Multivibrator work resemble Flip Flop. Which encourage itself repeatedly. The Q1 and Q2 be Transistor PNP be usable general (2N3906, 2N2907, etc. ) The R1 and R2 limit current that flow through LED the bilateral. If....
This circuit uses the TLC555CP timer I. C. to flash an LED roughly twice every second. This particular type of 555 timer will run off only 3 volts so two 1. 5 volt cells can be used. With "AA" cells, you can expect a battery life of up to 6 months. With....
Do not try this circuit unless you have good knowledge about electronic devices. This circuit is connected to main power source (220V) and can give you a high electrical shock ..
This simple LED torch is driven by a 2-transistor blocking oscillator which steps up the voltage from a 1. 5V cell. It relies on the inherent current limiting of the 150 µH choke to protect the white LED from over-drive. With a 9V zener diode in place of the....
In addition to providing an accurate input current limit, the LT1618 can also be used to provide a regulated output current for current-source applications. White LED drivers are one such application for which the LT1618 is ideally suited. With an input....
In the circuit diagram for the Joule Thief, the common point of the toroid is the connection at the top of the hand-wound ferrite toroid, in the upper right of the diagram. This goes to the positive end of the battery. The other two wires from the toroid go....
This is a simple LED torch circuit based on IC MAX660 from MAXIM semiconductors. The MAX 660 is a CMOS type monolithic type voltage converter IC. The IC can easily drive three extra bright white LEDs. The LEDs are connected in parallel to the output pin 8 of....
This circuit will flash a bright red LED (5000 mcd) as an attention getting device or fake car alarm. Component values are not critical and other transistors may be used. Flash duration is determined by R2 and C1 and is approximately 3 time constants....
This circuit drives as many as four white LEDs in parallel from a 3. 3V source, and adjusts the total LED current from 1mA to 106mA, in 64 steps of 1dB each. The circuit of Figure 1 is designed for portable-power applications that require white LEDs with....
Many consumer products using white light LEDs for illumination and backlighting provide gradual LED illumination at turnon and turnoff. This gradual illumination is usually achieved with the aid of a Microprocessor that provides PWM dimming control. This....
Can be directly connected to CD players, tuners and tape recorders. Simply add a 10K Log potentiometer (dual gang for stereo) and a switch to cope with the various sources you need. A correct grounding is very important to eliminate hum and ground loops.....
This is an 250mW RF power amplifier project. This circuit is designed to amplify the output of about 7mW wide band FM transmitters to a final level of about 250mW. This electronic circuit is a simple 2-transistor VHF power amplifier, with about 16dB gain,....
the decision of designing a 9V powered Headphone Amplifier was finally taken. The main requirement was to power the circuit by means of a common, PP3 (transistor radio) alkaline battery. The appearance of the 5534 low-noise op-amp at a reasonable price was....
The FM Remote Control Receiver` (available on this website in Infra-red circuits section) has a connector where an analogue output is made available. To make a simple intercom or P. A. system the associated transmitter needs a microphone pre-amplifier that....
A popular project among microcontroller aficionados is to build a radio-controlled clock. Tiny receiver boards are available, with a pre-adjusted ferrite antenna, that receive and demodula..
This is a great audio amplifier circuit based on single power IC TDA7294. TDA7294 is intended for use as a high quality audio class AB amplifier in hi-fi applications. It has very low noise ..
The modem off indicator is intended especially for serious Internet surfers. It will be seen that the circuit of the indicator cannot be much simpler, or there might be nothing left. In spite of its simplicity, it may prove to be a cost-saving device, since....
It can be used as part of intercoms, walkie-talkies, low-power transmitters, and packet radio receivers. Transistors T1 and T2 form the mic preamplifier. Resistor R1 provi..
The common characteristic of all of the previous low power FM transmitters I`ve built over the decades, is that their operating frequency is determined by an LC resonant circuit. ..
However effective a domestic alarm system may be, it`s invariably better if it never goes off, and the best way to ensure this is to make potential burglars think the premises are occupied. Indeed, unless you own old masters or objects of great value likely....
The cause may be dry solder joints, defective LEDs etc. , but also a flat battery (perhaps due to stuck key). The human eye is unable to perceive infra-red light. By contrast, an ordinary photo transistor like the BP103 has no problems working in the....
Easy to build high-quality PLL FM transmitter with typical output power of 5 W and no-tune design. The transmitter includes RDS/SCA input and Audio/MPX input with optional pre-emphasis. It can be used with or without stereo encoder. Tuning over the FM band....
The circuit presented here illustrates the fact that in spite of all kinds of new component and technology, it is still possible to design useful, and interesting, circuits. The circuit is based on two well-established transistors, a Type BF256C and a BF494.....
Here is a simple circuit for a one transistor Audion type radio powered by a 1. 5 V battery. It employs a set of standard low-impedance headphones with the headphone socket wired so that the two sides are connected in series thus giving an impedance of 64 ©.....
The signal from a microphone is two weak for a standard line input. This low-noise DC-coupled microphone amplifier provides a solution for anyone who wants to connect a microphone to his or her hi- installation. As can be seen from the schematic diagram, a....
STK4038 bassed 60 watt audio amplifier circuit project and explanation Using the STK4038X audio amplifier IC, can be designed a very simple high power and efficiency audio power amplifier. This circuit is manufactured by Sanyo Corporation and will provide a....
This electronic project stereo amp is based on the STK415-090-E class H audio power amplifier hybrid IC that features a built-in power supply switching circuit. This STK415-090-E class H audio power amplifier provides high efficiency audio power....
The orientation of the camera at launch is looking out the side of the rocket and during descent on the parachute, it is looking down. To allow the camera to look down during lift off, an external mirror can be optionally added. Located in the nose cone of....
This 3V FM transmitter Circuit is about the simplest and best basal transmitter to body and accept a advantageous transmitting range. It is decidedly able admitting its baby basic calculation and 3V operating voltage. It will calmly access over three floors....
Nowadays the most commonly available headphones have an impedance of 2 G— 32 ©, this relatively low value makes them unsuitable for such a design. However, with a bit of crafty transformation these headphones can be used in just such a design. To adapt them,....
The output frequency alternates between about 2100 Hz and 2200 Hz. This is a very distinctive test signal that is easily distinguished from any other signals that may be present. ..
About a do-it-yourself alarm arrangement body with PIC18F452. It`s a abundant amusement activity although the schematic is actual complicated. This activity uses three capital accessories to actualize the claimed alarm system. The IR Ambit sensor gives....
A stereo power amp designed for use in portable players and radios. A 3V supply can be used to drive headphones providing 20mW in..
The wireless transmitter ambit congenital about transistor T1 (BF494) is a basal low-power variable-frequency VHF oscillator. A varicap diode ambit is included to change the abundance of the fm transmitter and to accommodate abundance accentuation by audio....
This wireless headphones transmitter assures a affection accession over 2 meters. The oscillator abundance is amid 1750KHz and 3500KHz and for antenna we use a ferrite bar. IC1 amplifies the audio arresting and TC1 is a buffer. D1 signals that the....
The ambit of frequencies for the FM advertisement bandage is 90MHz (MHz = Megahertz or 90 actor cycles per second). Because the FM microphone has a capricious acquainted circuit, it can be acquainted to a quiet atom on your bounded FM advertisement bandage....
This FM transmitter circuit uses four radio abundance stages: a VHF oscillator congenital about transistor BF494 (T1), a preamplifier congenital about transistor BF200 (T2), a disciplinarian congenital about transistor 2N2219 (T3) and a ability amplifier....
This is an UHF bandage TV antenna preamplifier circuit With 15dB accretion to body easily. It is formed based on BF180 UHF Transistor. The aboriginal date is an bandage canyon clarify complete by the C1, CV1, L1, L4, C7 and C3, the additional date is a....
This accomplishing is acclimatized to rebroadcast the achievement of a CD player, television receiver, or radio receiver. I use it so that I can move about the abode and accept to my admired programs after advancing others. Within and the house, I....
I accept acclimated a brace of BC548 transistors in this circuit. Although not carefully RF transistors, they still accord acceptable results. I accept acclimated an ECM Mic admit from Maplin Electronics, adjustment cipher FS43W. It is a two terminal ECM,....
This Fm rf ability amplifier has 2 transistors from Philips : BLV 10 and BLW 87. The 2 rf transistors assignment in chic C and this fm amplifier has a absolute accretion of 21dB ( 100 X ) and ability 55 65%. One low canyon clarify with 9 apparatus ensures....
Here you got it! 300 W rf authentic ability for fm transmission. 300 W radio ability amplifier for accomplished 88 108 MHz ! This fm amplifier has 2 TP9383 abundant to bear up to 300W. ..
The important allotment of the circuit is formed of the Colpitts blazon oscillator. C3, C4, C5, C6, CD1-CD2 and L1 determines the frequency. BF982 and bifold aboideau MOSFET are alive genitalia in oscillator. When the ascribe impedance of the MOSFET aboideau....
You may admit abounding of the date circuits - as they are agnate to those acclimated in some of my added projects. The VFO and the RF ascribe bandage canyon clarify are anniversary advised about bowl resonators. These are acceptable difficult to locate.....
Servos became valuable products for any variety of plans, like robotics, automation or only remotely controlling some thing, for example model vehicle steering. They`re reasonably low-priced and also simple to have hold of, however controlling them can be a....
The 60Watt RF (Radio Frequency) Amplifier is simple all solid accompaniment ambit application ability mosfet IRF840. The IRF alternation of ability transistors are accessible in assorted voltage and ability ratings. A distinct IRF840 can handle best ability....
This simple counter can be used to count pulses, as the basis for a customer counter (like you see at the doors of some stores), or for anything else that may be counted. The circuit accepts any TTL compatible logic signal, and can be expanded easily ..
The ambit of AM transmitter is advised to address (amplitude modulated) DSB (double ancillary band) signals. A articulate AM arresting consists of a carrier and two symetrically spaced ancillary bands. The two ancillary bands accept the aforementioned....
It`s a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn....
The circuit was meant to be powered by a power supply, which is why there is no transformer, rectifier, or filter capacitors on the schematic. There is no reason why you cannot add these. To use the circuit, hook it up to a power supply/plug it in. Then,....
Thanks to the fully complementary PNP/NPN output configuration the TDA7383 allows a rail to rail output voltage swing with no need of bootstrap capacitors. The extremely reduced components count allows very compact sets. The on-board clipping detector....
It is good idea to put this circuit in a box and mark/write each LED with number 1 to 6. Now, when switch S1 is pushed momentarily, any one of the 6 LEDs will glow. The Number marked for glowing LED becomes dice`s output. Every time S1 is released, new LED....
This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just....
This ambit is a simple two transistor (2N2222) mini FM transmitter. No authorization is appropriate for this transmitter according to FCC regulations apropos wireless microphones. If powered by a 9 volt array and acclimated with an antenna no best than 12....
The affection of the ability accumulation is a Tamura 3FD-410 5V bifold primary/dual accessory transformer. These are accessible from DigiKey. com for reasonable prices. Normally, the transformer`s primary windings would be affiliated in alternation for....
The circuitis a simple one transistor amplifier with amplification of about 30-40 dB (depends on transitor, temperature and voltage). The dynamic mic input is just a simple one transistor amplifier circuit with nothing special in it. LED D1 is inthe....
When the water is empty the wires in the tank are open circuited and the 180K resistors pulls the switch low hence opening the switch and LEDs are OFF. As the water starts filling up, first the wire in the tank connected to S1 and the + supply are shorted by....
This circuit can be used to monitor the voltage level of a car battery. When the battery voltage is 11. 5V or less the transistor Q1 is on and D1 glowing. When LED battery voltage is between 11. 5 to 13. 5 V, the transistor Q2 is on and the glowing LED D2.....
This circuit inverter converts 12V DC battery to AC 22oV as the replacement of home energy. The inverter can be used for small electronic devices such as lamps, radio, phone charger, disc player, etc. The inverter circuit is a central component, the CMOS....
Explore power amplifier integrated circuit from National Semiconductor LM4780. What`s so special Well, first of all - a very low harmonic distortion. In general, manufacturers indicate the maximum power of his ingenious craft regularly with the harmonic....
This circuit will amplify voice audio in the range of 50 to 10, 000 cycles with little distortion, and have the ability to drive a low impedance load to 16 ohms. The circuit will run from 6 to 15 vdc and give about 20 dB of gain. To build an inexpensive....
The circuit was meant to be powered by a power supply, which is why there is no transformer, rectifier, or filter capacitors on the schematic. There is no reason why you cannot add these. To use the circuit, hook it up to a power supply/plug it in. Then,....
The LM380 is a power audio amplifier for consumer applications. In order to hold system cost to a minimum, gain is internally fixed at 34 dB. A unique input stage allows ground referenced input signals. The output automatically self-centers to one-half the....
The MAX2605, MAX2609 are compact, high performance intermediate frequency (IF) voltage-controlled oscillator (VCO) designed specifically for demanding portable wireless communication systems. They combine monolithic construction with low noise, low operating....
This simple amplifier is ideal for adding a headphone jack to equipment that lacks this feature. The Headphone Buffer circuit board is small enough (1. 2" X 1. 4") to squeeze into even the smallest spaces and power requirements are so low that existing....
This inverter circuit can offer a really stable 230V Output Voltage. Frequency of operation is decided by a VR1 and is generally set to 60 Hz. varied off the shelf transformers can be used. Or Custom wind your own for best results. additional MosFets can....
The LM3875 is an audio amplifier for high power output capable of delivering 56W of continuous average power to a load 8. The performance of the LM3875, utilizing its maximum instantaneous auto temperature ( ° Ke) (Spike ) protection circuitry, places it in....