Many electrical appliances can be repaired or new ones can be made with your own hands. For this home, there will always be something that can be converted to perform new functions: an old electronic watch, a children's car, an out-of-use computer and much more. Useful crafts can always be repaired or remade. It is better to have a workshop with tools for work.

Equipped master's home workshop

power unit

Homemade electronic devices require different voltages. In particular, soldering requires a regulated power supply. This opportunity can be provided by the LM-317 chip, which is a voltage stabilizer.

Regulated power supply circuit

Devices based on this circuit allow you to change the output voltage within 1.2-30 V using a variable resistor P1. The permissible current is 1.5 A, the power of the device depends on the choice of transformer.

The voltmeter is adjusted using trimming resistor P2. To do this, set the current to 1 mA at a circuit output voltage of 30 V.

The greater the difference between the input and output signals, the more power is allocated to the microcircuit. To reduce heat, it requires a radiator with a cooler.

A homemade board with an LM-317 chip is placed in a case - a computer power supply. A voltmeter and clamps for the output wires are installed on the front PCB panel.

Simple auto tester

A sampler for cars and other purposes should always be on hand at home, in the garage or on the go. The figure below shows a homemade circuit that allows you to check electrical circuits with a resistance of up to 10 kOhm and the presence of a voltage of 6-15 V.

Two indication circuits are connected in series to the battery and in parallel to each other. The first consists of resistor R1 and LED HL1, which lights up when checking the voltage. At the same time, the battery is recharged.

Circuit and design: a) homemade circuit, which allows you to check electrical circuits with a resistance of up to 10 kOhm and the presence of a voltage of 6-15 V; b) homemade design of a test probe

When a circuit is tested, current flows from the battery through circuit HL2, R2. At the same time, the HL2 LED lights up. Its brightness will be greater, the lower the circuit resistance.

Like all homemade products, the tester can be constructed in different ways, for example, by placing it in a transparent plastic case, which is easy to glue together with your own hands.

Such devices are indispensable when repairing an electrical network or household appliance at home. Crafts can be more complex and have additional functions.

Electric devices for heat treatment of meat products without the use of fuel are made for a small number of portions and can be used at home or in the country. To prepare barbecue using an electric barbecue maker, there is no need to spend expensive hours of rest standing outside at the barbecue.

In specialized stores you can choose any device, but the price decides a lot. If you have skills in handling electricity, it will be much cheaper to make an electric kebab maker with your own hands.

The structures are made in horizontal or vertical design. The power of the device usually does not exceed 1.5 kW. The meat is heated using a spiral with a tungsten or nichrome thread. All metal parts are made of stainless steel.

Typical devices are vertical heaters in the center and skewers with product around. They are attached from above. It is advisable to make skewers in the form of spirals, from which the meat does not slide down during the cooking process.

Vertical type of electric kebab maker

To make high-quality barbecue with your own hands, the skewers should be placed as close as possible to the heater, but so that the product does not touch the spiral. When placed at a distance, the meat will not fry, but will dry out.

Pieces of product no larger than 40 mm in size are placed on a skewer, which is placed vertically around the heater. Then the electricity is turned on and the coil is heated.

The heater is based on a heat-resistant ceramic tube on which a spiral is wound. Fastening at the bottom is done using a special cartridge.

In the round base there are special cups for collecting fat and a frame that serves to hold the skewers vertically.

Cups are made of stainless steel. They have cross-shaped protrusions at the bottom, which are inserted into the slots in the base. Inside they have devices for attaching skewers. Fixing the cup on both sides allows them to hold the skewers vertically.

The connection must be strong and at the same time easy to disassemble for cleaning. You can make a common removable tray for all skewers.

The cross-section of the supply wire is selected to match the power of the heater (2.5 or 4 mm2). At home or in the country there should be a 16 A socket for it.

Timer for watering plants

Devices with timers are used for drip irrigation of an area from a container at a certain time. They can be connected to valves with any capacity.

Often branded devices do not provide the required reliability. Then an old wall clock comes to the rescue, which is in working order, but is no longer used at home. Small magnets are attached to the ends of the minute and hour hands, and there are 3 reed switches on the dial.

Timer circuit for watering plants, which uses a wall clock

As soon as the hour hand reaches the number 7, and the minute hand reaches 12, which corresponds to the time of 7 o'clock, the reed switches SA1 and SA3 are triggered and the signal opens the solenoid valve. After 2 hours, the arrows will move to 9 and 12, and current will flow through the contacts of the reed switches SA1 and SA2 to close the valve.

The diagram shows a “rain sensor”, which in wet weather closes transistor VT1 and the valve remains constantly closed. Manual control of the solenoid valve is also provided via buttons S1 and S2.

The clock can be set to any time the valve is turned on.

Car with remote control

Homemade radio-controlled models captivate not only children, but also adults. They can be used for playing at home or for real competitions in the yard. To assemble it yourself, you will need a chassis with wheels, an electric motor and a housing.

There is a large assortment on sale, but first of all you need to decide which machine is best to make. The control panel can be wired or radio controlled.

When choosing parts, you should pay attention to their quality. The plastic should be free of nicks, inclusions and other mechanical defects. The wheels are sold with the chassis and should turn easily. Grip on the surface is better provided by rubber. Plastic wheels are much worse in this regard.

For a beginner, it is better to take an electric motor, which is cheaper and easier to maintain than an internal combustion engine. You can choose any body or make it according to your own sketch.

The motor, battery and radio unit with antenna are installed on the chassis of the mini-car. If you purchase a kit with components, assembly instructions are included.

After installing the parts, the operation of the motor is adjusted. The housing is installed on the chassis after everything is working.

You can assemble mini-copies at home as follows:

the car is assembled carefully and through joint efforts;
the materials of the model parts may differ from the original;
small and insignificant details can be omitted.

The model can be made without focusing on a specific car brand. Much depends on finances and availability of free time. Assembling a mini-car at home with a child has great educational value.

The work on assembling the car model is carried out according to plan. Some parts need to be purchased, but you can use old toys.

The power of the motor must match the weight of the device. Fresh batteries or accumulator are used for power supply.

If you use a special car designer, crafts can be very diverse. Assembly sequence:

the frame is assembled first;
the motor is attached and adjusted;
the power supply is installed;
the antenna with the radio unit is fixed;
wheels are installed and adjusted.

Types of radio-controlled car models

Many DIY tricks are revealed in this video.

Electronic homemade products can make life more comfortable and save a lot of money. In addition, you can find a use for old electrical appliances so that they do not gather dust in the pantry without a purpose. Useful DIY crafts are often better than factory-made products.

One of the common hobbies of amateurs and professionals in the field of electronics is the design and manufacture of various homemade products for the home. Electronic homemade products do not require large material and financial costs and can be done at home, since work with electronics is, for the most part, “clean”. The only exception is the manufacture of various body parts and other mechanical components.

Useful electronic homemade products can be used in all areas of everyday life, from the kitchen to the garage, where many are engaged in improving and repairing car electronic devices.

Homemade products in the kitchen

Kitchen electronics crafts can be a complement to existing accessories and fixtures. Industrial and homemade electric kebab makers are very popular among apartment residents.

Another common example of kitchen homemade products made by a home electrician is timers and automatic switching on of lights above work surfaces, and electric ignition of gas burners.

Important! Changing the design of some household appliances, especially gas appliances, may cause “misunderstanding and rejection” by regulatory organizations. In addition, it requires great care and attention.

Electronics in the car

Homemade devices for cars are most widely used among owners of domestic brands of vehicles, which are distinguished by a minimal number of additional functions. The following schemes are in wide demand:

Sound indicators for turns and handbrake;
Battery and generator operating mode indicator.

More experienced radio amateurs are equipping their cars with parking sensors, electronic window drives, and automatic light sensors to control low beam headlights.

Homemade crafts for beginners

Most novice radio amateurs are engaged in the manufacture of structures that do not require high qualifications. Simple proven designs can serve for a long time and not only for the sake of benefit, but also as a reminder of the technical “growing up” from a beginner radio amateur to a professional.

For inexperienced hobbyists, many manufacturers produce ready-made construction kits that contain a printed circuit board and a set of elements. Such sets allow you to practice the following skills:

Reading schematic and wiring diagrams;
Correct soldering;
Setup and adjustment using a ready-made method.

Among the sets, electronic watches of various designs and degrees of complexity are very common.

As an area of application of knowledge and experience, radio amateurs can design electronic toys using simpler circuits or modifying industrial designs to suit their wishes and capabilities.

Interesting ideas for crafts can be seen in the examples of making radio-electronic crafts from worn-out computer parts.

Home workshop

To independently design radio-electronic devices, you need a certain minimum of tools, devices and measuring instruments:

Soldering iron;
Side cutters;
Tweezers;
Screwdriver Set;
Pliers;
Multifunctional tester (avometer).

On a note. When planning to do electronics yourself, you should not immediately take on complex designs and purchase an expensive tool.

Most radio amateurs began their journey by using a simple 220V 25-40W soldering iron, and the most popular Soviet tester, the Ts-20, was used in the home laboratory. All this is enough for practicing with electricity, acquiring the necessary skills and experience.

There is no point in buying an expensive soldering station for a novice radio amateur if he does not have the necessary experience with a conventional soldering iron. Moreover, the possibility of using the station will not appear soon, but only after sometimes quite a long time.

There is also no need for professional measuring equipment. The only serious device that even a novice amateur may need is an oscilloscope. For those who already understand electronics, an oscilloscope is one of the most sought-after measurement tools.

Inexpensive digital devices made in China can be successfully used as an avometer. Having rich functionality, they have high measurement accuracy, ease of use and, importantly, have a built-in module for measuring transistor parameters.

When talking about a DIY home workshop, one cannot fail to mention the materials used for soldering. This is solder and flux. The most common solder is POS-60 alloy, which has a low melting point and provides high soldering reliability. Most solders used for soldering all kinds of devices are analogues of the mentioned alloy and can be successfully replaced with it.

Ordinary rosin is used as a flux for soldering, but for ease of use it is better to use its solution in ethyl alcohol. Rosin-based fluxes do not require removal from installation after operation, since they are chemically neutral under most operating conditions, and the thin film of rosin formed after evaporation of the solvent (alcohol) exhibits good protective properties.

Important! When soldering electronic components, active fluxes should never be used. This is especially true for soldering acid (zinc chloride solution), since even under normal conditions such flux has a destructive effect on thin copper printed conductors.

To service heavily oxidized terminals, it is better to use active acid-free flux LTI-120, which does not require rinsing.

It is very convenient to work using solder that contains flux. The solder is made in the form of a thin tube, inside of which there is rosin.

For mounting elements, breadboards made of double-sided foil fiberglass, which are produced in a wide range, are well suited.

Security measures

Working with electricity is associated with risks to health and even life, especially if the electronics are designed with your own hands with mains power. Homemade electrical devices should not use transformerless power from a household AC network. As a last resort, such devices should be configured by connecting them to the network through an isolation transformer with a transformation ratio equal to unity. The voltage at its output will correspond to the network voltage, but at the same time reliable galvanic isolation will be ensured.

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 devices needed for everyday life from old equipment. Today, repair and assembly of equipment for the home or cottage, for a car or garage can also be solved at home.

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Homemade devices for home and garden

Electrical homemade products for home and garden that use the power of electricity can be made by every electrician. Most devices are created using factory components and require only school knowledge of electricity.

Electric kebab maker

The electric kebab maker can be either horizontal or vertical. Stores usually sell vertical ones, and they do their job well after some modification.

To create a horizontal barbecue grill you will need a heating element and a frame resembling a barbecue. The heating element can be made from a ceramic tube and a nichrome spiral wound around it. The tube is secured through an insulating material in a metal casing. Drawings will be required to assemble the case.

Barbecue grill

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

Homemade WI-FI antenna

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

For production you need:

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

Manufacturing process:

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

Necessary materials Insert the pin into the drilled hole Glue the USB cable Securing the cable Tripod Installing the antenna using a tripod

Electrical homemade products for the garage

Let's look at several useful DIY projects for the garage.

Homemade chandelier

If you have poor lighting in your garage, then a makeshift chandelier will be very useful. To make a bifurcating chuck, you will need a pair of angular chucks, which are sold at a regular hardware store.

Sequencing:

We remove the wires from the sockets and fasten them with a plastic tie. We get a socket for two lamps. All that remains is to connect them to the electrical network.
To do this, we use the base of a fluorescent lamp. Carefully break out the lamp, then solder the wires from our design to the contacts of the base.
We insulate them well and attach the base on top of the cartridges.

The use of ordinary light bulbs in this design is undesirable - the sockets may melt from heating.

LED device

Another lighting option could be a homemade LED lighting device.

To make it you will need:

old fluorescent lamp;
LED Strip Light;
connecting wires.

The manufacturing sequence is as follows:

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

Spot welding machine

A necessary device in the garage will be a homemade 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 process of assembling the welder is quite simple:

The transformer is dismantled.
Carefully remove the secondary winding.
Two shunts are removed.
A secondary winding of two or three turns is made of thick wire (with a diameter of at least 10 mm).
Electrodes for resistance welding are made from a copper rod with a diameter larger than the wires.

Homemade spot welding tool

Useful DIY items for fishing

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

Electronic alarm

An example would be an electronic signaling device for fishing with a regular fishing rod or other equipment. A simple biting device can be assembled in just half an hour. For it you will need an old beeper keychain and a strip of plastic 1-2 mm thick.

Alarm assembly:

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

Now when the fish bites, 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

Using a homemade underwater camera for winter fishing, you can see if there is fish under the hole. And this simplifies the fishing process.

To make it you will need:

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

Build process:

Two holes are made in the upper part of the box. An extension cable is inserted through one. Through the second is the wire that connects the camera to the TV.
Several more holes are made in the box 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.
The holes are sealed with glue and tape for a tight seal.
Lead is melted and small elongated bars are poured out of it. They are placed at the bottom of the box.
Set up the camera and connect it to the cable. After which it is carefully placed in the box so that it has a clear forward and horizontal direction and transmits a high-quality image. For stability, the chamber is surrounded by soft material.
A torso (rope, belt) is attached to the box, which will be used to lower the camera to depth. For convenience, you can combine it, the power cable and the communication wire between the video camera and the TV into one core, secured with electrical tape.
Connect the power cable of the video camera to the battery and test the device.

Homemade fish bait

You can make a good bait for fishing yourself. This will be a device assembled based on a simple multivibrator.

You will need:

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

The bait is assembled as follows:

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

Bait scheme - 1 Bait scheme - 2

Electronic homemade products for cars

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

Electrical auto tester

A simple homemade electrical probe is perfect for a car. It can show the presence of a voltage of 12 volts in an electrical circuit. It is used to check the serviceability of relays, as well as light bulbs and other equipment. You can make such a device from a syringe and LEDs.

Assembly diagram:

Two LEDs are soldered with opposite terminals (plus one to the minus of the other and vice versa).
A steel probe is connected to one of the solders through a resistance of 300 Ohms. To the other solder there is a contact for batteries.
The design is inserted into the syringe so that the probe comes out of the hole for the needles. Most of the probe is insulated with a PVC pipe.
4 LR44 batteries are inserted into the syringe so that one of the poles is connected to the LED contact.
The other pole of the batteries is connected to a flexible wire with an alligator clip.

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

Light switch

The scheme for smoothly turning off the lights in the car interior is quite simple to manufacture. Such electronics are suitable for any car. A small board consisting of a capacitor and diodes is soldered parallel to the interior lamp terminals. The drop in electricity voltage will occur gradually and create the effect of a gradually fading light.

Car subwoofer

To make a car subwoofer with your own hands, you must first purchase a speaker. You need to start from its dimensions when calculating the size of the case.

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

LED fog lights

You can make LED car fog lights with your own hands.

For creativity you will need:

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

Instructions for assembling the craft:

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

Car carrying

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

Manufacturing scheme:

Remove the contacts from the USB plug.
In the plug body we connect the wires of the lamp and the car alligator clips.
To mount it in the right place (even horizontally), a magnet is placed on the plug.

Those who do radio electronics at home are usually very inquisitive. Amateur radio circuits and homemade products will help you find a new direction in your creativity. Perhaps someone will find an original solution to this or that problem. Some homemade products use ready-made devices, connecting them in different ways. For others, you need to completely create the circuit yourself and make the necessary adjustments.

One of the simplest homemade products. More suitable for those who are just starting to craft. If you have an old but working cell phone with a button to turn on the player, you can use it, for example, to make a doorbell for your room. The advantages of such a call:

First you need to make sure that the selected phone is capable of producing a sufficiently loud melody, after which it must be completely disassembled. Basically, the parts are secured with screws or staples, which are carefully folded back. When disassembling, you will need to remember what goes with what, so that later you can put everything back together.

The player's power button is unsoldered on the board, and two short wires are soldered in its place. These wires are then glued to the board so the solder doesn't come off. The phone is going. All that remains is to connect the phone to the call button via a two-wire wire.

Homemade products for cars

Modern cars are equipped with everything you need. However, there are times when homemade devices are simply necessary. For example, something broke, they gave it to a friend, and the like. That’s when the ability to create electronics with your own hands at home will be very useful.

The first thing you can tamper with without fear of damaging your car is the battery. If you don’t have a battery charger at hand at the right time, you can quickly assemble it yourself. To do this you will need:

A transformer from a tube TV is ideal. Therefore, those who are interested in homemade electronics never throw away electrical appliances in the hope that they will be needed someday. Unfortunately, two types of transformers were used: with one and with two coils. To charge a battery at 6 volts, any will do, but for 12 volts only two.

The wrapping paper of such a transformer shows the winding terminals, the voltage for each winding and the operating current. To power the filaments of electronic lamps, a voltage of 6.3 V with a high current is used. The transformer can be remade by removing the extra secondary windings, or you can leave everything as is. In this case, the primary and secondary windings are connected in series. Each primary is rated at 127 V, so combining them produces 220 V. The secondary are connected in series to produce an output of 12.6 V.

Diodes must withstand a current of at least 10 A. Each diode requires a radiator with an area of at least 25 square centimeters. They are connected into a diode bridge. Any electrical insulating plate is suitable for fastening. A 0.5 A fuse is included in the primary circuit, and a 10 A fuse in the secondary circuit. The device does not tolerate short circuits, so the polarity should not be confused when connecting the battery.

Simple heaters

During the cold season, it may be necessary to warm up the engine. If the car is parked where there is electrical current, this problem can be solved using a heat gun. To make it you will need:

asbestos pipe;
nichrome wire;
fan;
switch.

The diameter of the asbestos pipe is selected according to the size of the fan that will be used. The performance of the heater will depend on its power. The length of the pipe is everyone's preference. You can assemble a heating element and a fan in it, or just a heater. When choosing the latter option, you will have to think about how to allow air flow to the heating element. This can be done, for example, by placing all components in a sealed housing.

Nichrome wire is also selected according to the fan. The more powerful the latter, the larger diameter nichrome can be used. The wire is twisted into a spiral and placed inside the pipe. For fastening, bolts are used that are inserted into pre-drilled holes in the pipe. The length of the spiral and their number are selected experimentally. It is advisable that the coil does not become red hot when the fan is running.

The choice of fan will determine what voltage needs to be supplied to the heater. When using a 220 V electric fan, you will not need to use an additional power source.

The entire heater is connected to the network via a cord with a plug, but it itself must have its own switch. It can be either just a toggle switch or an automatic machine. The second option is more preferable; it allows you to protect the general network. To do this, the triggering current of the machine must be less than the triggering current of the room circuit breaker. A switch is also needed to quickly turn off the heater in case of problems, for example, if the fan does not work. This heater has its disadvantages:

harmful to the body from asbestos pipes;
noise from a running fan;
smell from dust falling on the heated coil;
fire hazard.

Some problems can be solved by using another homemade product. Instead of an asbestos pipe, you can use a coffee can. To prevent the spiral from closing on the jar, it is attached to a textolite frame, which is fixed with glue. A cooler is used as a fan. To power it, you will need to assemble another electronic device - a small rectifier.

Homemade products bring those who do them not only satisfaction, but also benefits. With their help, you can save energy, for example, by turning off electrical appliances that you forgot to turn off. A time relay can be used for this purpose.

The simplest way to create a time-setting element is to use the charging or discharging time of a capacitor through a resistor. Such a chain is included in the base of the transistor. The circuit will require the following parts:

high-capacity electrolytic capacitor;
pnp type transistor;
electromagnetic relay;
diode;
variable resistor;
fixed resistors;
DC source.

First you need to determine what current will be switched through the relay. If the load is very powerful, you will need a magnetic starter to connect it. The starter coil can be connected via a relay. It is important that the relay contacts can operate freely without sticking. Based on the selected relay, a transistor is selected and it is determined what current and voltage it can operate with. You can focus on KT973A.

The base of the transistor is connected through a limiting resistor to a capacitor, which, in turn, is connected through a bipolar switch. The free contact of the switch is connected through a resistor to the power supply negative. This is necessary to discharge the capacitor. The resistor acts as a current limiter.

The capacitor itself is connected to the positive bus of the power source through a variable resistor with high resistance. By selecting the capacitance of the capacitor and the resistance of the resistor, you can change the delay time interval. The relay coil is shunted by a diode, which turns on in the opposite direction. This circuit uses KD 105 B. It closes the circuit when the relay is de-energized, protecting the transistor from breakdown.

The scheme works as follows. In the initial state, the base of the transistor is disconnected from the capacitor, and the transistor is closed. When the switch is turned on, the base is connected to the discharged capacitor, the transistor opens and supplies voltage to the relay. The relay operates, closes its contacts and supplies voltage to the load.

The capacitor begins to charge through a resistor connected to the positive terminal of the power source. As the capacitor charges, the base voltage begins to rise. At a certain voltage value, the transistor closes, de-energizing the relay. The relay switches off the load. In order for the circuit to work again, you need to discharge the capacitor; to do this, switch the switch.

So. Life has turned out in such a way that I have a house in the village with gas heating. It is not possible to live there permanently. The house is used as a summer house. For a couple of winters I stupidly left the boiler on with the minimum coolant temperature.
But there are two disadvantages.
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, it was necessary to invent something.
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.

Connecting a 4-pin motion sensor with your own hands (diagram)

DIY motion sensor connection diagram

It happens that you need to install lighting in your dacha or in your home. will be triggered by movement or a person or someone else.

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

In this article I’ll tell you how to connect such a sensor if it doesn’t have 3 contacts, but 4 like this one.

DIY 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 for smooth adjustment variable resistor fan speed.

The circuit of the floor fan speed controller turned out to be the simplest. To fit into the case from an old Nokia phone charger. The terminals from a regular electrical outlet also fit in there.

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

DIY plant lighting

There may be a problem with lack of lighting plants, flowers or seedlings, and there is a need for artificial light for them, and this is the kind of light we can provide on LEDs with your own hands.

DIY brightness control

It all started after I installed halogen lamps for lighting at home. When turned on, they often burned out. Sometimes even 1 light bulb a day. Therefore, I decided to make a smooth switching on of the lighting based on a brightness control with my own hands, and I am attaching a diagram of the brightness control.

DIY refrigerator thermostat

It all started when I returned from work and opened the refrigerator to find it warm. Turning the thermostat control 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 myself using the ATtiny85. The difference with the original thermostat 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 turned on or the temperature is above the upper threshold.

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 on which you can make a simple 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 90 mA, 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 supply circuit

Power supply circuit for a fluorescent lamp.

Often when energy-saving lamps fail, it is the power supply circuit that burns out, and not the lamp itself. As is known, LDS with burnt filaments, it is necessary to supply the network with rectified current using a starterless starting device. In this case, the filaments of the lamp are bridged by a jumper and a high voltage is applied to it to turn on the lamp. There is an instantaneous cold ignition of the lamp, with a sharp increase in voltage across it, upon start-up without preheating the electrodes. In this article we will look at starting an LDS lamp with your own hands.

USB keyboard for tablet

Somehow, suddenly, I took something and decided to buy a new keyboard for my PC. The desire for novelty is irresistible. Changed the background color from white to black, and the letter color from red-black to white. A week later, the desire for novelty naturally disappeared like water into 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, she didn’t even imagine that it would happen so quickly. And therefore the name would be even better suited not which is, but how to connect a usb keyboard to a tablet.