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How to build Modular Preamplifier Switching Center - circuit diagram

Hits:352 Audio

DescriptionThis module can be a necessary addition to the Modular Preamplifier Control Center when more than two sources need to be connected to the preamplifier chain. Four high level inputs...

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How to build Safety Guard - circuit diagram

Hits:372 Clocks, timers, relays, load switches

DescriptionProtect your home appliances from voltage spikes with this simple time delay circuit. Whenever power to the appliances is switched on or resumes after mains failure, the oscillator starts oscillating...

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Simple Digital Volume Control

Hits:449 Audio

This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This...

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Refinement of the telephone server, the РНОNЕ МАSТЕR and caller ID box KALKOFEN

Hits:419 Telefonie

Multi-function phone with caller ID (server) "Рhоnе Маstеr" and caller ID-prefix "Kalkofen", developed by the company TeleSystems, no doubt, lead the market, as their the apparent advantage is the volatility...

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Specialized power supply

Hits:427 Power supplies

In Fig. 4.6 shows a diagram of a power source that maintains its performance even in case of voltage loss in the network, wherein the device switches...

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Automatic lighting in the toilet

Hits:589 Lighting

It often happens when someone from the household forgets to turn off a the light in the toilet - it can burn there without the use of a lot of...

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The design of broadband transformers

Hits:386 Filters and matching devices

In an article on the design of broadband transformers (SHPT) on the ferrite rings for LW transistor power amplifiers, it is noted that the cross section of the ring should...

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One little antenna...

Hits:642 Television aerials

This is the conclusion I have come gradually. But here's the thing. To view TV shows are most commonly used active combo M/DM In antenna (AKA) with reduced size. Many...

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Converter with UHF surfactants filter for narrow-band AM/FM

Hits:994 Filters and matching devices

To the transmitting and receiving devices in the UHF range very often used a master oscillator with a quartz resonator and the subsequent frequency multiplication. It complicates the design and...

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Stereo VU Booster

Hits:1474 Audio

This is a stereo VU booster circuit diagram based on transistor FCS9014 which usually used for pre-amp and regulator circuit and switching. With simple circuit design, this device could be...

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Active DC Voltage Doubler

Hits:492 Power supplies

Here is the circuit diagram of active DC voltage doubler which used to increase the DC voltage.This circuit drives relays of 24 and 18VDC from a 12V power supply. Use...

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Distortion Booster

Hits:503 Audio

The following circuit is an distortion booster effect for your electric guitar. I don’t know whether this circuit is really works or not, you may try this circuit with your...

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How to build Dual-rail Variable DC Power Supply - circuit diagram

Hits:375 Power supplies

DescriptionThis design was conceived as an add-on for the Variable DC Power Supply, a very successful circuit posted to this website. This simple unit provides a dual-rail variable output ranging...

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Logic PSU With Over-Voltage Protection

Hits:363 Power supplies

A simple 5 Volt regulated PSU featuring overvoltage protection. The 5 volt regulated power supply for TTL and 74LS series integrated circuits, has to be very precise and tolerant of...

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12/24/48 V D.C. Tester

Hits:744 Other

The present tester is intended primarily for testing the 24 V electrical circuits found on most pleasure craft. However, if the resistors are given different values, the circuit may, of...

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Repair VCRs and videoplayer. LMP in the apparatus of the SHARP firm

Hits:1278 Television and video

VCRs (videoplayer) company SHARP early issues with asymmetric the location of the slot often fail due to a malfunction elements of LSM. Defects, discussed below, most devices (such as VC-6V3...

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Simple Darkness Activated Alarm

Hits:312 Other

Most darkness activated alarms employ opamps and some logic ICs. Here, a less expensive approach is shown based on the eternal 555, this time in monostable multivibrator mode. Components R2...

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Compact switching power supply 12 volts 2 amps

Hits:656 Power supplies

The proposed self SMPS (switching power supply) has a small size and high efficiency. Its feature is that the magnetic core pulse transformer works with entering into the saturated region...

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Led or Lamp Flasher Circuit

Hits:422 Lighting

Ideal to operate 3 to 24V DC existing on-circuit lampsThis circuit was designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit...

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Halogen Lamp Dimmer With Soft Start

Hits:581 Lighting

Most dimmers use pulse width modulation (PWM) to control the amount of power that is delivered to the lamp. Those that come bundled with a switch faceplate control the firing...

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Alarm Power Supply

Hits:500 Power supplies

This Power Supply is suitable for the Modular Burglar Alarm. However, it has other applications. It is designed to provide an output of 12-volts, with a current of up to...

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Simple adjustable power supply on a chip L4960, 5,1-40 volts 2.5 amps

Hits:1018 Power supplies

Modern circuitry and chip manufacturers cool make life easier for the designer - for example, when creating an supply. We will demonstrate it on the chip...

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The fuel-injection system KE-Jetronic

Hits:1882 Electronic fuel injection

The system includes a fuel pump, the drive of the fuel, fuel filter, pressure regulator fuel in the system, the doser-dispenser fuel, electro-hydraulic control pressure regulator, an injector and a...

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Harmonic Generator With Single Opamp

Hits:323 Other

Quartz crystals have the property that their amplitude/phase characteristic repeats itself at frequencies that are an uneven multiple of the fundamental frequency. There are so-called overtone crystals that are cut...

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Electronics against mosquitoes

Hits:464 House, garden land, hobby

Summer comes, and with it come the mosquitoes, and all sorts of other midges. Everyone knows how annoying mosquitoes, especially at night.The proposed device allows to be protected from all...

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Automotive 12V to +-20V converter (for audio amplifier)

Hits:503 Power supplies


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The dipole antenna

Hits:1075 Shortwave antenna

On the construction of the attention of the reader antenna was told on the radio 10-15 years ago ham V. Volia beach (UA6DL), for which the author is very grateful...

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The infrared locator for the blind

Hits:498 Medicine

Relatively small in size, infrared (IR) warns locator the sound signal of the approach to any obstacle (wall, fence) or object. The signal appears at a distance to the obstacle...

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Home time service

Hits:455 Clocks, timers, relays, load switches

Hoping to equip the apartment "talking" for hours, tried to collect an acceptable design using typical domestic chips. But once faced with the complexities of "firmware" electronic...

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How to build A 555 -Timer Based Motorcycle Alarm - circuit diagram

Hits:833 Security devices and alarm

DescriptionThis circuit features an intermittent siren output and automatic reset. It can be operated manually using a key-switch or a hidden switch; but it can also be wired to set...

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Infrared Remote Receiver Has Four Outputs

Hits:322 Other

This circuit enables any infrared (IR) remote control to control the outputs of a 4017 decade counter. It's quite simple really and uses a 3-terminal IR receiver (IRD1) to pick...

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Discrete Robot

Hits:521 Other

This simple robot, which responds to light and avoids obstacles, can be built without using a microcontroller, programmer or PC. The only ‘special’ component in the circuit is a window...

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Bicycle back Safety Light

Hits:573 Lighting

Flashing 13 LED unit, 3V supplyAlso suitable for jogger/walkersCircuit diagramParts:R1 10K 1/4W ResistorR2,R9,R10 100K 1/4W ResistorsR3-R8,R11-R16 10R 1/4W ResistorsR17 150R 1/4W ResistorC1...

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The speakerphone device for a loudspeaker handset

Hits:434 Telefonie

The speakerphone device for a loudspeaker handset. Publication: N. Bolshakov,

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Dual Polarity 5 Volt Converter Using LM2685

Hits:383 Power supplies

A symmetrical ±5V power supply is often needed for small, battery-operated operational amplifier projects and analogue circuits. An IC that can easily be used for this purpose is the National...

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Powerful PSU, 220/32 volt 1000 watt

Hits:471 Power supplies

To reduce the size and weight mains power supplies in recent years more wider use conversion voltage at a frequency of several tens of kilohertz. This source contains a mains...

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Amateur metal detector

Hits:8890 Metal detectors

I developed the metal detector has not been used neither in peace operations to identify and neutralize minefields, nor in large-scale geological or archaeological surveys. Designed not for professionals but...

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Simple BFO Metal Locator

Hits:355 Indicators, detectors

This circuit uses a single coil and nine components to make a particularly sensitive low-cost metal locator. It works on the principle of a beat frequency oscillator (BFO). The circuit...

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Flyback cascaded SMPS, 220/12,6 volts 0.5 amps

Hits:1366 Power supplies

In we offer our readers the article description and principle of operation practical scheme SMPS based cascaded flyback voltage Converter. No discharge voltage at the drain...

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TDA7381 4 x 25W Quad Audio Amplifier

Hits:944 Audio

The following is 4 x 25W quad audio amplifier circuit (amplifier with four inputs and four outputs) based TDA7381. This amplifier is designed for car audio system, but you can...

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Simple DFT

Hits:420 Filters and matching devices

We offer a simple the bandpass filter of the transceiver. Feature filter is the use of only two main inductors. The filter circuit shown in the figure.These vessels are...

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Active High Pass Filter Using LM741

Hits:698 Other

This is active high pass filter circuit for 327Hz frequency using LM741. It will use to build Harmonic at 3 of 130.81 frequency have the value at least. More than...

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The connection to modern acoustics car audio

Hits:584 Audio

Recorders with four-channel bridge amplifierFor four-channel bridge amplifier, which is equipped with almost all modern audio players, these options enable the AU can be combined in different ways. For example...

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Servo Tester Using A 4538

Hits:349 Other

There are times when a small servo tester for modelling comes in very useful. Everybody who regularly works with servos will know several instances when such a servo tester will...

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Three consoles to telephones

Hits:542 Telefonie

The device as will be explained below, are designed to the extension of the functional opportunities phone devices that enhance usability use of them...

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Laboratory power supply with adjustable current limit, 0-30 volt 3 ampere

Hits:948 Power supplies

To adjust or repair of electronic devices you need to have a few power sources. Many homes already have such devices, but, as a rule, they have...

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The sound effects generator

Hits:392 Bells and audio simulators

We offer you a scheme that is able to amuse children. It can to generate the sounds of police car siren, warble of birds, the sounds of space ships, etc...

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Integrated timers in automobile anti-theft system

Hits:537 Security devices and alarm

On the basis of just two cheap integrated type 555 timers, you can collect affordable automobile anti-theft system. Its schematic diagram is shown in figure 1.Fig.1The timer And performs a...

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Copper multi-band VHF antenna Cactus

Hits:958 VHF antenna

We hope that You are already familiar with the design standard J-antenna, so will not delve into unnecessary details. The proposed antenna is a variation of the J-antenna and can...

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