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Directional antenna with vertical polarization

Hits:900 Shortwave antenna

New solutions are not often appear in antenna technology. To them, without a doubt, proposed last year by Vladimir Polyakov an interesting variant of two-element directional antenna with...

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The switching power supply on a chip LM2577, 220/3,5-30 volts 0.2 ampere

Hits:417 Power supplies

Widespread pulse DC-DC power supplies, due to their higher efficiency compared to linear. Although they concede less linear stability of the output voltage, but with a significant change of the...

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Mesa Boogie Dual Rectifier

Hits:2446 Audio

The following diagram is Mesa Boogie dual rectifier solo head schematic diagram. This is a tubed pre-amp and tubed amplifier designed and manufactured by Mesa Boogie. The following schematic is...

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Sensitive detector

Hits:1165 Metal detectors

First of all I want to immediately dispel preconceived notions about a person with a metal detector, as the Defiler of graves or the "black Ranger", relation mafia weapons during...

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Audio indicator ultrasound

Hits:1305 Indicators, detectors

Ultrasounds around us everywhere, it can be "negotiations" animals noises of various equipment, as well as ultrasounds are specially generated the sounders, medical devices. Unlike the sounds of the audible...

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Automatic temperature controller for the infield

Hits:836 Power controllers, thermometers, heat

When growing seedlings and plants in greenhouses or on heated soil is important constantly to maintain temperature within specified limits. This function successfully performs automatic thermostat, electric contact is made...

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The test antenna amplifiers SWA

Hits:875 Antenna amplifiers

The results of the test amplifier SWA for Polish antennas. No. Model 50 MHz 230 MHz 470 MHz 800 MHz I ponv., mA The number of transistors Notes 1...

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Automatic switch phases

Hits:558 Clocks, timers, relays, load switches

In the national economy is widely used equipment powered from three-phase network requiring observance of the phase sequence. Usually this is achieved the corresponding switching wires, but during various renovations...

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Multipurpose water activators

Hits:408 House, garden land, hobby

I activated electric water appear special properties: this moisture has a significant influence on the course of oxidation-reduction processes in animate and inanimate nature. Using water activated, enthusiasts achieve success...

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How to build Portable 9v Headphone Amplifier - circuit diagram

Hits:402 Audio

DescriptionAfter several requests by correspondents, 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...

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Storage music call on PIC16F84

Hits:622 Bells and audio simulators

Sometimes you want to know: "is not called in the door when no one was home?". This will help offer a musical call that has a special memory function. Made...

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Modern selectors TV channels with frequency synthesis

Hits:775 Television and video

Selectors, the principle of which is based on the synthesis frequency, called selectors PLL ("Phase Locked Loop", which translated to English means "closed loop PLL"). These selectors are also called...

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NiMh and NiCd Battery Charger Circuit

Hits:468 Power supplies

This automatic NiCd charger for 9V NiCd batteries is using 555 timer properties and is very easy to build. Why is an automatic 9 volts NiCd battery charger? Because you...

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Hits:593 Power supplies

Ham radio operators often offer their products in print or on circuit boards. In their manufacture have to drill a large number holes of small diameter (0.8... 1.2...

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Vertical antenna for LF ranges

Hits:665 Shortwave antenna

The problem of creating an effective antenna for the bands 160, 80 and 40 meters for working in confined spaces concern to many hams, including me. Previously used LW, Dipole...

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Semiautomatic machine for the eternal lamp bulb

Hits:335 Lighting

One of the designers of the T-34 - Koshkin said that the most reliable detail - TA, which is not. Here and in the proposed semi-automatic machine for "eternal" lamp...

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The calculation of the acoustic reflex

Hits:1178 Audio

The proposed calculation method based on simple measurements performed with the well-defined instance of a loudspeaker mounted in bass reflex and acoustic on demograficheskim determining the size of the latter.In...

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Musical call to chip KID

Hits:397 Bells and audio simulators

Such a call can be set in the apartment instead of the usual electric. And then when you press the button at the front door of the apartment filled with...

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Smooth start-up pulse transformer and power supply units

Hits:437 Power supplies

When you turn on power supplies amplifiers, laboratory and other BP occurs in the network interference caused by inrush currents transformers, the charge currents electrolytic capacitors...

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The current limit indicator

Hits:621 Power supplies

In the operation of laboratory power supplies often there is a need monitor the current consumed by the load. In most cases, with this purpose in the output...

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How to build Transformerless 5 Volt Power Supply - circuit diagram

Hits:375 Power supplies

DescriptionAn increasing number of appliances draw a very small current from the power supply. If you need to design a mains powered device, you could generally choose between a linear...

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Pipe Descaler

Hits:372 Other

For many years now, magnetic (or electromagnetic) water descaler devices have been showing up on the shelves of Home Improvement and other DIY stores all over Europe. Despite the numerous...

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Radio transmitters with wideband FM in the frequency range 65-108 MHz

Hits:1400 Radio transmitters

The radio microphone, schematic diagram of which is shown in Fig. 8. operates in the frequency range 65-108 MHz with wideband frequency modulation. This allows you to take the signal...

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TV antenna for cell phone

Hits:481 Telefonie

As is known, to the territories covered with reliable cellular communication, abut areas where communication is not guaranteed. Usually this is because because of the terrain straight wave is very...

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TV transmitter

Hits:576 Television and video

A schematic diagram of a transmitter placed in Fig.1.The transmitter operates in the UHF range (UHF) and is built on one chip and two microwave transistors. It ensures the perfect...

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Wireless microphone-radio repeater with power supply from telephone line

Hits:688 Wireless microphones

There are radio repeatersthat allow you to not only listen to a phone conversation without the tube, but the conversation in the room where they are installed in the handset...

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Car power supply for laptop

Hits:1005 Power supplies

Modern portable computers, so-called, laptops, are popular. They are much more comfortable with their stationary counterparts. The laptop can be put in a bag and take with you, for example...

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Metal detectors category FD (Frequency Domain), the theory

Hits:792 Metal detectors

Encyclopedia of electronics and electrical engineering Free library / Schematic of electronic and electrical devicesMetal detectors category FD (Frequency Domain), theory Encyclopedia electronics and electrical engineering /...

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Dependent inclusion of electric and radio devices

Hits:385 Clocks, timers, relays, load switches

The device is designed to automatically turn on a single electronic of the device when turning the other. The first one is called the slave, and the second - leading...

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The ultrasonic generator to scare the rats

Hits:382 House, garden land, hobby

This generator can be used in the storage of grain and other facilities for food storage. The oscillator circuit shown in the figure, consists of a low frequency modulator (C1...

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Mains Indicator

Hits:382 Indicators, detectors

It is not always immediately obvious whether a power-consuming appliance is switched on or not. Examples are the lamp in the attic or the shed, or electric heating in an...

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Manage network load TTL chip

Hits:381 Clocks, timers, relays, load switches

The following scheme allows you to manage network load (220V) from of devices formed on the chip and having an output TTL level. Scheme has opto isolation, which allows a...

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Burglar-alarm device

Hits:927 Security devices and alarm

This autostorage in comparison with similar devices, published in the magazine "Radio" earlier, does not have any fundamental innovation. However, he interesting that assembled only three chips and four transistors...

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The subwoofer from scrap materials

Hits:585 Audio

Long in the corner gathering dust domestic AC electronics 015 based on 75 HDH-1-4 and it disturbed (throw a pity). And the subwoofer in the car was not, however, then...

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Dual Polarity 5 Volt Converter Using LM2685

Hits:345 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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How to build Timed Beeper - circuit diagram

Hits:304 Clocks, timers, relays, load switches

Beeps 7.5 seconds after a preset timeAdjustable time settings: 15 sec. 30 sec. 1 min. 2 min. & othersCircuit diagramParts:R1 220R 1/4W ResistorR2 10M 1/4W ResistorR3 1M 1/4W ResistorR4 10K...

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Flyback Transformer Driver

Hits:504 Power supplies

Circuit diagram General Description and circuit operation:This is an efficient flyback driver for modern cylindrical rectified television flybacks. Many sites doesn't provide circuits driving these transformers, they simply say that...

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Dark Activated Terrace Lamp

Hits:367 Lighting

Compact circuit, Can be wired in parallel to existing switchesThis device allows one or more lamps to illuminate at sunset and turn off at dawn.Q1 and Q2 form a trigger...

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How to build 12Vdc to 220Vac 50W Converter - circuit diagram

Hits:362 Power supplies

Description In a lot of cases we needed a 220VAC voltage, in spaces where it does not exist, in order to we supply with power, various small appliances. In the...

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Power amplifier with a field effect transistor as a current source for the input stage and the balancing elements of the output stage

Hits:531 Audio

It has the following main technical characteristics: Rated output power....... 75 watts THD.......... 0,06% The bandwidth of.......... 20 ... 40 000 Hz The signal-to-noise.......... 86 dB The voltage........... ±40 In...

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Managing chandelier with four lights

Hits:490 Lighting

The proposed device allows using a conventional switch with one pair of contacts to control a chandelier with four lights, including one, two, three or all four.The first time after...

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Led car strobe

Hits:1040 Ignition system

Know about the importance of setting optimum ignition of the combustible the mixture in the cylinders of a gasoline engine for maximum power, efficiency and proper temperature. The implementation of...

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Switch TV antenna with power and control cable

Hits:639 Television aerials

When using the viewers several television antennas, receiving signals from different directions on different bands and channels you receive their loss-free transmission to the TV with the best quality. How...

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Connection Tester

Hits:307 Other

A low resistance ( 0.25 - 4 ohm) continuity tester for checking soldered joints and connections. This simple circuit uses a 741 op-amp in differential mode as a continuity tester...

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Caller ID-the prefix to the Electronic computer, the Secretary

Hits:556 Telefonie

Every year computer equipment all firmly embedded in our lives. Continuously multiplies the number of users of personal computers. In this regard the question arose: is it possible to expand...

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Battery Voltage Indicator

Hits:632 Indicators, detectors

Monitors battery voltage, Three-LED DisplayConnecting this circuit to the battery of your vehicle, you will always know at a glance the approximate voltage available. An indication of battery voltage is...

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The transmitter average power with a compact loop antenna

Hits:581 Radio transmitters

The transmitter operates in the range of 65-73 MHz with frequency modulation. The range in the use of framework compact antenna is about 150 m. the Duration of operation of...

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Improvement head of direct radiation

Hits:523 Audio

The impact head direct radiation that is produced it sound pressure, as is known. proportional to the vibrational speed of the diffuser. The acceleration of the cone is proportional to...

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Temperature controller sting of a soldering iron

Hits:454 Power controllers, thermometers, heat

This controller differs from similar published the fact that it regulates (reduces) heat capacity of the soldering iron does not change its voltage supply and the interruption of the current...

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