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» Homemade unusual electronic. What do-it-yourself electronic homemade products can be made? Fluorescent lamp power circuit

Homemade unusual electronic. What do-it-yourself electronic homemade products can be made? Fluorescent lamp power circuit

Making electronic homemade products with your own hands gained popularity in the last century, when semiconductor devices appeared. With their help, it was quite easy to assemble the devices necessary for everyday life from old equipment. Today, the repair and collection of equipment for a home or a summer residence, for a car or a garage can also be solved at home.

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Homemade devices for home and garden

Electric homemade products for home and summer cottages, using the power of electricity, can be done by every electrician. Most fixtures are built from factory components and require only school knowledge of electricity.

Electric barbecue

The electric grill can be either horizontal or vertical. Stores usually sell vertical ones, and they do their job perfectly after some refinement.

To create a horizontal barbecue, you will need a heating element and a frame resembling a brazier. You can make a heating element from a ceramic tube and a nichrome spiral wound around it. The tube is fixed through an insulating material in a metal housing. Drawings are required to assemble the case.

Barbecue grill

An equally interesting idea is a barbecue grill with an electric drive for rotating skewers. By adding an electric motor to a regular brazier, you can get an excellent device that will cook barbecue offline. To organize a skewer drive, you can use a motor from the wipers, from a washing machine or any other 12 volt motor. With the help of a system of pulleys and a belt or gear drive, the rotation of the shaft is transmitted to the skewers, and the meat slowly turns over the coals.

Homemade WI-FI antenna

Such an antenna will improve the reception quality and speed of Wi-Fi in your home. According to reviews, after connecting it, the signal level rises from 5 to 27 Mbps.

For manufacturing you need:

  • a small metal sieve or colander;
  • Wi-Fi adapter (USB);
  • USB cable;
  • drill;
  • epoxy resin;
  • camera tripod;
  • plastic clamps.

Manufacturing process:

  1. We drill a small hole (14 mm) in the center of the sieve and insert a metal pin into it to fix the adapter.
  2. We insert the connector from the USB cable into the prepared hole and fix it with epoxy. The USB connector after gluing must be strictly perpendicular to the plane of the sieve, then the device works more efficiently.
  3. Then, with the help of two ties, “ears” are made through which the cable is attached.
  4. We fix the product on a camera tripod. We drill a hole with a diameter of 12 mm in the antenna and clamp it with a nut.

Necessary materials Insert the pin into the drilled hole Attaching the USB cable We fix the cable Tripod Mounting the antenna with a tripod

Electric homemade for the garage

Consider several projects of useful homemade products for the garage.

homemade chandelier

If you have low lighting in the garage, then an impromptu chandelier will be very useful. To make a bifurcated cartridge, you will need a pair of angle cartridges, which are sold in a regular hardware store.

Sequencing:

  1. We remove the wires from the cartridges and fasten them with a plastic tie. We get a cartridge for two lamps. It remains to connect them to the electrical network.
  2. To do this, we use the base of a fluorescent lamp. We carefully break out the lamp, then solder the wires from our design to the contacts of the base.
  3. We isolate them well and attach the base on top of the cartridges.

The use of conventional light bulbs in such a design is undesirable - the cartridges can fuse from heating.

LED device

Another lighting option can be a homemade LED lighting device.

For its manufacture you will need:

  • old fluorescent lamp;
  • LED Strip Light;
  • connecting wires.

The manufacturing sequence is as follows:

  1. An LED strip is glued onto the lamp body in one or several rows.
  2. The connecting wires are connected and brought to the lamp switch.
  3. The assembled device is tested.

Spot welding machine

The necessary device in the garage will be a home-made spot welding machine, the basis of which is a transformer from an old microwave oven. A necessary condition is that the transformer must be working in order not to rewind all the windings.

The assembly process of the welder is quite simple:

  1. The transformer is dismantled.
  2. Carefully remove the secondary winding.
  3. Two shunts are removed.
  4. From a thick wire (with a diameter of at least 10 mm), a secondary winding of two or three turns is made.
  5. From a copper bar with a diameter larger than the wires, electrodes for contact welding are made.

Homemade spot welding tool

Useful DIY things for fishing

Among homemade products, you can find many interesting ideas for use in field conditions, as well as hunting and fishing.

Electronic signaling device

An example is an electronic signaling device for fishing with a conventional fishing rod or other tackle. A simple bite device can be assembled in just half an hour. For it, you will need an old tweeter keychain and a strip of plastic 1-2 mm thick.

Assembly of the signaling device:

  1. The keychain is attached to the rod.
  2. A strip of plastic is glued to the fishing line and inserted between the contacts of the key fob.

Now, when biting, the fish will pull the line, the plastic will fly out, the contacts will close and the key fob will work.

Underwater camera for ice fishing

With the help of a homemade underwater camera for ice fishing, you can see if there are fish under the hole. This makes the fishing process easier.

For manufacturing you will need:

  • small chamber;
  • sealed box for the camera;
  • small TV;
  • car battery to power the camera;
  • extension;
  • inverter;
  • lead for cargo;
  • ultraviolet diodes for illumination at underwater shootings;
  • superglue, electrical tape, sealant.

Assembly process:

  1. Two holes are made at the top of the box. An extension cable is inserted through one. Through the second - the wire with which the camera is connected to the TV.
  2. In the box, several more holes are made into which light bulbs are inserted for illumination. The wires from the light bulbs are soldered into one circuit (for example, with a parallel arrangement), which is connected to a cable that provides power.
  3. Holes are sealed with glue and electrical tape for tight sealing.
  4. Lead is melted and small elongated bars are poured out of it. They are placed at the bottom of the box.
  5. Set up the camera, connect to the cable. After that, it is carefully placed in the box so that it has a clear direction forward and horizontally and transmits a high-quality image. For stability, the camera is surrounded by a soft material.
  6. A torso (rope, belt) is attached to the box, with which the camera will be lowered to a depth. For convenience, you can combine it, the power cable and the cable for connecting the video camera to the TV into one core, fastening it with electrical tape.
  7. Connect the camcorder's power cable to the battery and test the unit.

Homemade fish bait

You can make a good bait for catching fish yourself. This will be a device assembled on the basis of a simple multivibrator.

You will need:

  • a sound emitter, for example, from a children's toy;
  • wires;
  • a small plastic jar, for example, from under medicinal tablets;
  • electronic board;
  • regulator with plastic rod;
  • a piece of foam;
  • batteries;
  • float weights;
  • volume control.

The assembly of the bait is carried out as follows:

  1. You need to solder the circuit and check it.
  2. Two wires are soldered to the sound emitter. Then they are held inside the case and connected to the board.
  3. A regulator with a plastic rod is placed in the lid of the jar.
  4. A dense circle cut out of foam is installed on top of the board, which separates the board from the battery.
  5. Weights are fixed at the bottom of the jar so that the container is kept on the water like a float.
  6. The regulator sets the frequency and changes the sound.

Lure scheme - 1 Lure scheme - 2

Electronic homemade products for a car

Motorists create homemade products with their own hands to improve the appearance and ease of use of the car.

Electric autoprobe

For a car, a simple homemade electrical probe is perfect. It can show the presence of a voltage of 12 volts in an electrical circuit. With it, the health of the relay, as well as light bulbs and other equipment, is checked. You can make such a device from a syringe and LEDs.

Assembly diagram:

  1. Two LEDs are soldered with opposite terminals (plus one to minus the other and vice versa).
  2. A steel probe is attached to one of the solder joints through a resistance of 300 ohms. To the other soldering is a contact for batteries.
  3. The design is inserted into the syringe so that the probe comes out of the needle hole. Most of the probe is insulated with a PVC tube.
  4. 4 LR44 batteries are inserted into the syringe so that one of the poles is connected to the LED contact.
  5. A contact is made to the other pole of the batteries from a flexible wire with an alligator clip.

The video shows how to make a syringe tester. Filmed by ILYANOV channel.

Light switch

It is quite simple to manufacture a circuit for smoothly turning off the light in the car. Such electronics is suitable for any car. Parallel to the terminals of the cabin lamp, a small board is soldered, consisting of a capacitor and diodes. The drop in electricity voltage will occur gradually and will create the effect of a smoothly fading light.

car subwoofer

To make a car subwoofer with your own hands, you must first purchase a speaker. Its dimensions must be taken into account when calculating the size of the case.

The simplest and most successful form of a subwoofer for the trunk is a truncated pyramid with a slope like that of the rear seats.

LED fog lights

With your own hands, you can make car fog lights on LEDs.

For creativity you will need:

  • two ten-watt LEDs;
  • 2 lenses from an old projector;
  • gaskets from plastic pipes;
  • LM317T chips;
  • resistors.

Instructions for assembling crafts:

  1. LEDs are installed on pre-prepared aluminum radiators.
  2. A structure is assembled from headlight housings, lenses from projectors, gaskets and diodes on radiators.
  3. Fog lights are powered through current stabilizers on LM317T microcircuits and resistors.

Car carrier

A very convenient car carrying is obtained from a computer USB lamp. It is compact and you can connect the device to any place in the vehicle wiring.

Manufacturing scheme:

  1. We remove the contacts from the USB plug.
  2. In the plug housing, we connect the wires of the lamp and car crocodile clips.
  3. For fastening in the right place (even horizontally), a magnet is placed on the plug.

Every day it becomes more and more, there are many new articles, it is rather difficult for new visitors to immediately orient themselves and revise everything already written and previously posted at once.

I really want to draw the attention of all visitors to individual articles that were posted on the site earlier. In order not to have to search for the necessary information for a long time, I will make several "input pages" with links to the most interesting and useful articles on specific topics.

Let's call the first such page "Useful electronic homemade products". Here we consider simple electronic circuits that are available for implementation by people of any level of training. The schemes are built using a modern electronic database.

All information in the articles is presented in a very accessible form and in the amount necessary for practical work. Naturally, to implement such circuits, you need to understand at least the basics of electronics.

So, a selection of the most interesting articles on the site on the subject "Useful electronic homemade products". The author of the articles is Boris Aladyshkin.

The modern element base of electronics greatly simplifies circuitry. Even an ordinary twilight switch can now be assembled from just three parts.

The article describes a simple and reliable electric pump control circuit. Despite the extreme simplicity of the circuit, the device can operate in two modes: water lifting and drainage.

The article presents several schemes of apparatus for spot welding.

With the help of the described design, it is possible to determine whether a mechanism located in another room or building is working or not. The information about the work is the vibration of the mechanism itself.

A story about what a safety transformer is, why it is needed and how you can make it yourself.

Description of a simple device that disconnects the load in the event that the mains voltage is out of range.

The article discusses a simple thermostat circuit using an adjustable zener diode TL431.

An article on how to make a lamp soft start device using the KR1182PM1 chip.

Sometimes, with low voltage in the network or soldering massive parts, it becomes simply impossible to use a soldering iron. This is where a step-up power regulator for a soldering iron can come to the rescue.

An article about what can replace the mechanical thermostat of an oil heating radiator.

Description of a simple and reliable thermostat circuit for a heating system.

The article describes the converter circuit made on a modern element base, containing a minimum number of parts and allowing to obtain significant power in the load.

An article about various ways to connect the load to the control unit on microcircuits using relays and thyristors.

Description of a simple scheme for controlling LED garlands.

The design of a simple timer that allows you to turn on and off the load at specified intervals. Working time and pause time are independent of each other.

Description of the scheme and principle of operation of a simple emergency lamp based on an energy-saving lamp.

A detailed story about the popular "laser-ironing" technology for manufacturing printed circuit boards, its features and nuances.

Since you have decided to become a self-taught electrician, then for sure after a short period of time you will want to make some useful electrical appliance for your home, car or cottage with your own hands. At the same time, homemade products can be useful not only in everyday life, but also made for sale, for example,. In fact, the process of assembling simple devices at home is not difficult. You just need to be able to read diagrams and use a tool for radio amateurs.

As for the first point, before you start making electronic homemade products with your own hands, you need to learn how to read wiring diagrams. In this case, ours will be a good helper.

Of the tools for beginner electricians, you will need a soldering iron, a set of screwdrivers, pliers and a multimeter. To assemble some popular electrical appliances, you may even need a welding machine, but this is a rare case. By the way, in this section of the site we even talked about the same welding machine.

Special attention should be paid to improvised materials, from which every novice electrician will be able to make elementary electronic homemade products with his own hands. Most often, in the manufacture of simple and useful electrical appliances, old domestic parts are used: transformers, amplifiers, wires, etc. In most cases, it is enough for beginner radio amateurs and electricians to look for all the necessary tools in a garage or a barn in the country.

When everything is ready - the tools are assembled, spare parts are found and minimal knowledge is obtained, you can proceed to the assembly of amateur electronic homemade products at home. This is where our little guide will help you. Each instruction provided includes not only a detailed description of each of the stages of creating electrical appliances, but is also accompanied by photo examples, diagrams, as well as video tutorials that clearly show the entire manufacturing process. If you do not understand some point, you can clarify it under the entry in the comments. Our experts will try to advise you in a timely manner!

Electronic homemade products, today, are an affordable way to make useful mechanisms that can make life easier and diversify leisure. Modern craftsmen are able to assemble both simple toys and complex, multi-tasking mechanisms with their own hands. How to make electronic toys, interesting and useful electronic homemade products for home and car with your own hands - read below!

Do-it-yourself simple electronics: making a spinner

Electrical engineering, today, is widely used for both practical and recreational purposes. Some inventions (such as, for example, the “smart home” system) will be quite difficult for a beginner to make. They require experience and in-depth knowledge of physics. Other designs are simple and affordable for beginner radio amateurs. So, for example, you can make interesting toys with your own hands - spinners, sales of which have increased incredibly this year.

To assemble a toy, you will need to stock up:

  • Wooden blank measuring 9x4x1.2 cm;
  • Bearing size 2.2x0.8x0.7 cm (with rubber seal);
  • Two RGB LEDs;
  • Two batteries and CR2032 holders;
  • Stainless steel bolt 0.8x2 cm;
  • Cap nuts M8.

After that, you can get to work. First of all, it will be necessary to find a design scheme on the Internet, and transfer it to a raw bar - a blank. To correctly outline the technological holes (there will be three of them), you will need a ruler.


Then follows:

  1. In the middle of the workpiece, drill a through hole with a diameter of 2.2 cm for the bearing;
  2. Drill two holes on the sides of the workpiece with a diameter of 2.5 cm and a depth of 7.5 mm;
  3. Using a drill, make two holes in the middle of two blind holes with a diameter of 6 mm for the LEDs;
  4. Treat holes with a countersink;
  5. Give the toy a rounded shape with a jigsaw, band saw or jigsaw;
  6. Sand the workpiece with sandpaper, and varnish it;
  7. Solder the LEDs to the battery holders;
  8. Check the LEDs, and install them in the mounting holes, fixing them with super glue;
  9. Clean the bearing and treat its insides with WD 40;
  10. Cut off the head of the bolt, and fix the axle in the bearing on both sides with nuts;
  11. Install the bearing in the mounting hole.

Spinner is ready! The toy will be interesting not only for children. Adults can also use such an electronic device: the device, rotating, will help to relax or be distracted.

Simple schemes of electronic homemade products: we make an electric call

You can easily and quickly make an electric call with your own hands.

Such a call will last a long time, and will please the ear. After all, when pressed, it will be able to create signals of various frequencies and tonality.

So, an electric call can be single-tone and multi-tone.

The ability of a call to reproduce sound in one or more keys will be affected by the presence of a multivibrator with two bipolar transistors in the radio design circuit. Let us consider in detail the scheme of an electronic call with a complex sound signal.

So, an electronic home-made circuit will consist of the following radio components:

  • Step-down transformer of the TA series;
  • call button;
  • Five alloy silicon diodes;
  • Electrolytic capacitor with a capacity of 1000 microfarads
  • Two electrolytic capacitors with a capacity of 10 microfarads;
  • Two tuning resistors with a resistance of 470 kilo-ohms;
  • Two MLT resistors with a resistance of 10 kilo-ohms;
  • Two MLT resistors with a resistance of 33 kilo-ohms;
  • MLT resistor per 1 kilo ohm;
  • MLT resistor for 470 kilo-ohms;
  • Three silicon plenary transistors type 630D
  • Silicon-planar transistor type 630G.

The principle of operation of the device is simple. Pressing the button will turn on the third 630D type transistor, allowing current to pass to the fourth 630D type transistor. This will create the primary signal. When the second transistor of the 630D type is opened, the third and fourth transistors will lock up, creating a signal of a different tone.

DIY homemade for a car

Auto electronics, today, is in great demand. At the same time, home-made automation often has simple circuits, easy execution and installation. What electric homemade products can you do yourself for your car?

So, with your own hands for a car you can do:

  • Dynamic turn signals using KIT DIY;
  • Universal charger from old electronics;
  • Water pump air conditioner;
  • Heated wipers and more.

The easiest way would be to design a backlight for the seat belt buckles. To do this, it will be necessary to dismantle and disassemble the locks with a flat screwdriver. After that, with the help of hot glue in the locks, it is necessary to fix the LEDs.

Each LED can be turned on through its own current-limiting resistor: this will extend the life of the semiconductor light emitting device.

After that, you should assemble the locks, and stretch the wires that power the LEDs under the seats to the ignition or the size button through the cigarette lighter. At the request of the owner, the car interior lighting can be supplemented with lamps that signal that the seat belt is not fastened.

Unusual electronic homemade products: do-it-yourself binary clock

You can make a cool binary clock for your home with your own hands. To do this, you need the Arduino platform. Wiring diagrams on this platform are simple and convenient, they are used for the manufacture of most electronic homemade products.


In addition, to make a binary clock you will need:

  • Real time clock module on DS1302 chip;
  • Diffuse LEDs with a diameter of 1 cm (20 pieces);
  • Resistors with a resistance of 10 ohms (20 pieces);
  • Resistors with a resistance of 10 kilo-ohms (2 pieces);
  • Two tact buttons;
  • Frame.

The watch case should consist of two halves, which can be made of wood, plastic, metal. It depends on what style your watch will be. Before making the case, you will need to assemble the LED matrix.

In this case, each LED must be connected through its own current-limiting resistor.

After that, the outputs from the LEDs must be connected to the platform. The controller itself will need to be connected to the real time clock module. After that, the contacts from the Arduino and the module must be routed to the clock buttons to set the time through resistors with a nominal value of 10 kilo-ohms. They will serve as payloads. Finally, connect the power cable to the circuit.

Useful do-it-yourself homemade products: how household scales are made

Today, almost every home has a floor or kitchen scale. In order to independently make this useful measuring device, you need to understand its device and the principle of operation.

So, the external components of the scales include:

  • Weight processor;
  • Frame;
  • Screen for readings;
  • platform;
  • Legs.

The principle of operation of scales is extremely simple. The load, falling on the platform, presses on it due to gravity, activating the strain gauge weight sensor inside the device. The strain gauge, in turn, affects the strain gauge, changing its resistance. The latter transmits a signal to an analog-to-digital converter. After that, the ADC converts the signal into digital and sends it to the microcontroller, which draws conclusions about the weight of the load on the platform, and displays the values ​​on the screen.

When assembling the circuit, it is necessary to pay attention to the type of strain gauge.

So, for a central location under the platform of floor, trade and technical scales, it is better to choose a single-point sensor. For installation on a bend, a block sensor is used. At the same time, it is necessary to ensure that the load cell has a reliable connection to the ADC. A weight processor will help solve the problem of connecting devices.

Do-it-yourself radio circuits for the home: we make an electronic lock

Electricity can also serve to protect the house. So, today, do-it-yourself sites offer simple radio circuits for electronic locks for the front door. Opening such a lock using a physical key will not work.

The simplest circuit for making a lock is usually based on a four-digit Johnson counter.

This scheme can be implemented in several variations. The simplest one is using the 4017 chip. The principle of operation of the circuit is quite simple: when you enter the correct four-digit code, a logical unit is activated at the input of the microcircuit, which opens the lock.

Consider the operation of the device in more detail:

  • When the wrong keys are pressed, the circuit is restarted without triggering the mechanism through the RESET input.
  • The correct signal, when a key is pressed, should go to the field-effect transistor VT1, which, after opening, supplies voltage to the output corresponding to the key;
  • After the complete introduction of the correct code, from the output corresponding to the last correct key, the signal is applied to the transistor VT2 connected to the relay;
  • The transistor is activated for a time that determines the capacitance of the capacitor;
  • The relay opens the actuator (for example, a latch).

In order to open such a lock, you need to go through about ten thousand different codes. In this case, the numbers on the code should not be repeated. That is, code 3355 will not be possible, all digital values ​​must be different.

Most of the electronic homemade products that modern craftsmen make are designed to perform ordinary household tasks faster and better than authentic devices. So, for example, an electric spinning wheel will significantly speed up the process of creating yarn. You can quickly make an electric spinning wheel by putting the electric motor on an authentic device.

At the same time, the motor for the electric spinning wheel must have a power of at least 15 watts.

As an engine, it will be possible to use a motor from a fan, an auto-cleaner, a player. Use the foot pedal to start the engine. It will be possible to change the movements of the motor by including a TP-type toggle switch in the circuit, which provides the connection of the capacitor and resistance to different windings.

An electric fly swatter will be useful, easy to assemble and operate.

In order to implement such a mechanism, it will be necessary to assemble a standard blocking generator. At the same time, you will need to remember to isolate the handle of the fly swatter.

Where to find amateur radio circuits and homemade products

Modern sites of radio amateurs offer to make not only useful, but also unusual radio homemade products. So, for example, on the Mozgochina website you can find interesting electronic circuits for making refrigerator reminders, thermometers that change color depending on temperature, etc.

Interesting and useful will be electrical things for everyday life and crafts from improvised materials for fishing from the site “Visiting Samodelkin”.

You can read about how to design, debug and manufacture electronic mechanisms at home in the book “Entertaining Radio Electronics”. New items among radio homemade products are often posted by the site “Ham Radio Workshop”. Amusing and useful technical materials contain new issues of the Radio Amateurs magazine.

DIY homemade products at home (video)

Radioamateur clubs are, today, popular with both schoolchildren and adults. Master classes and radio circuits presented on various sites allow you to assemble almost any electrical appliance at home. The main thing is to find the right circuits, follow the instructions clearly, and adhere to safety precautions when working with electricity. And you can collect whatever you want!

So. Life has turned out so that I have a house in the village with gas heating. You can't live there permanently. The house is used as a summer cottage. A couple of winters stupidly left the boiler on with a minimum coolant temperature.
But there are two downsides.
1. Gas bills are astronomical.
2. If there is a need to come to the house in the middle of winter, the temperature in the house is around 12 degrees.
Therefore, something had to be invented.
I'll clarify right away. The presence of a WI-FI access point in the relay coverage area is mandatory. But, I think, if you get confused, you can put a connected mobile phone next to the sensor and give out a signal from the phone.

Do-it-yourself motion sensor connection 4 pins diagram

Do-it-yourself motion sensor connection diagram

It happens that you need to install lighting in the country, or in the house, which will be triggered when moving or a person or someone else.

The motion sensor, which was ordered by me from Aliexpress, works well with this function. The link to which will be below. By connecting light through the motion sensor, when a person passes through his field of vision, the light turns on, burns for 1 minute. and turns off again.

In this article I tell you how to connect such a sensor if it does not have 3 contacts, but 4 like this one.

Do-it-yourself power supply from an energy-saving light bulb

When to get 12 volts for LED strip, or for some other purpose, there is an option to make such a power supply with your own hands.

DIY fan speed controller

This regulator allows smooth adjustment variable resistor fan speed.

The floor fan speed controller circuit came out the simplest. To fit into the case from an old Nokia phone charger. There also climbed the terminals from a conventional electrical outlet.

The installation is quite tight, but this was due to the size of the case.

DIY lighting for plants

DIY lighting for plants

There is a problem with the lack of lighting. plants, flowers or seedlings, and there is a need for artificial light for them, and this is the light we can provide DIY LEDs.

DIY brightness control

DIY brightness control

It all started with the fact that after I installed halogen lamps at home for lighting. When turned on, they often burned out. Sometimes even 1 bulb a day. Therefore, I decided to make a smooth turn-on of lighting based on a dimmer with my own hands, and I am attaching a dimmer circuit.

Do-it-yourself refrigerator thermostat

Do-it-yourself refrigerator thermostat

It all started with the fact that after returning from work and opening the refrigerator found it warm. Turning the thermostat knob did not help - the cold did not appear. Therefore, I decided not to buy a new unit, which is also rare, but to make an electronic thermostat on the ATtiny85 myself. With the original thermostat, the difference is that the temperature sensor is on the shelf, and not hidden in the wall. In addition, 2 LEDs appeared - they signal that the unit is on or the temperature is above the upper threshold.

DIY soil moisture sensor

DIY soil moisture sensor

This device can be used for automatic watering in greenhouses, flower greenhouses, flower beds and indoor plants. Below is a diagram by which you can make the simplest sensor (detector) of soil moisture (or dryness) with your own hands. When the soil dries out, voltage is applied, with a current of up to 90mA, which is quite enough, turn on the relay.

It is also suitable for automatically turning on drip irrigation to avoid excess moisture.

Fluorescent lamp power circuit

Power supply circuit for a fluorescent lamp.

Often, when energy-saving lamps fail, the power circuit burns out in it, and not the lamp itself. As is known, LDS with burned-out filaments, it is necessary to feed the mains with rectified current using a starterless starting device. In this case, the filaments of the lamp are shunted with a jumper and to which a high voltage is applied to turn on the lamp. There is an instantaneous cold ignition of the lamp, a sharp increase in voltage on it, when starting without preheating the electrodes. In this article, we will look at do-it-yourself LDS lamp start.

USB keyboard for tablet

USB keyboard for tablet

Somehow, suddenly, he took something and decided to buy a new keyboard for his PC. The desire for novelty is unstoppable. Changed the background color from white to black, and the color of the letters from red - black to white. A week later, the desire for novelty naturally went away like water in the sand (an old friend is better than two new ones) and the new thing was sent to the closet for storage - until better times. And now they came for her, did not even imagine that it would happen so quickly. And therefore the name would be even better suited not which is, but how to connect usb keyboard to tablet