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

One of the easiest crafts. More suitable for those who are just starting to tinker. 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 to your room. Benefits of this 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 fastened with screws or brackets, which are carefully bent. When disassembling, you will need to remember what goes for what, so that later you can reassemble everything.

The player's power button is soldered on the board, and two short wires are soldered instead. These wires are then glued to the board so as not to tear off the solder. The phone is going. It remains to connect the phone to the call button through a two-wire wire.

Homemade for cars

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

The first thing you can intervene in without fear of damaging the car is the battery. If at the right time charging for the battery was not at hand, you can quickly assemble it yourself. This will require:

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

The wrapping paper of such a transformer shows the winding leads, the voltage for each winding, and the operating current. To power the filaments of electronic lamps, a voltage of 6.3 V with a large current is used. The transformer can be redone by removing unnecessary secondary windings, or left as is. In this case, the primary and secondary windings are connected in series. Each primary is designed for a voltage of 127 V, therefore, by combining them, they get 220 V. The secondary ones are connected in series to get 12.6 V at the output.

Diodes must be capable of withstanding at least 10 A. Each diode requires a heat sink of at least 25 square centimeters. They are connected to a diode bridge. Any electrical insulating plate is suitable for fastening. A 0.5 A fuse is included in the primary circuit, and 10 A in the secondary circuit. The device does not tolerate a short circuit, therefore, when connecting the battery, the polarity must not be confused.

Simple heaters

In the cold season, it may be necessary to warm up the engine. If the car is parked where there is electricity, this problem can be solved with a heat gun. For its manufacture you will need:

• asbestos pipe;
• nichrome wire;
• fan;
• switch.

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

Nichrome wire is also selected by 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. Bolts are used for fastening, which are inserted into pre-drilled holes in the pipe. The length of the spiral and their number are chosen empirically. It is desirable that the coil does not heat up red-hot when the fan is running.

The choice of fan will determine how much voltage you need to apply 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 through a cord with a plug, but it must have its own switch. It can be either just a toggle switch or an automatic one. The second option is more preferable, it allows you to protect the overall network. To do this, the tripping current of the machine must be less than the tripping current of the room machine. A switch is also needed to quickly turn off the heater in case of malfunctions, for example, if the fan does not work. Such a heater has its drawbacks:

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

Some problems can be solved by applying another homemade product. Instead of an asbestos pipe, you can use a coffee can. So that the spiral does not close 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 to the one who deals with them not only satisfaction, but also benefit. With their help, you can save electricity, for example, by turning off electrical appliances that you forgot to turn off. For this purpose, you can use a time relay.

The easiest way to create a timing element is to use the charge or discharge time of a capacitor through a resistor. Such a chain is included in the base of the transistor. The diagram will require the following details:

• high capacity electrolytic capacitor;
• p-n-p 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. According to the selected relay, a transistor is selected, it is determined with what current and voltage it can work. 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 minus power supply. 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 supply through a variable resistor with a large 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 that 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 supply. As the capacitor charges, the base voltage begins to rise. At a certain voltage value, the transistor closes, de-energizing the relay. The relay disconnects the load. To make the circuit work again, you need to discharge the capacitor, for this the switch is switched.

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 performed 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 life, from the kitchen to the garage, where many are engaged in improving and repairing car electronic devices.

DIY in the kitchen

Homemade kitchen electronics can be an addition to existing accessories and accessories. Industrial and home-made electric barbecue grills are very popular among residents of apartments.

Another common example of do-it-yourself home-made kitchen products by a home electrician are timers and automatic switching on of lighting above work surfaces, electric ignition of gas burners.

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

Electronics in the car

Home-made devices for a car are most widely used among owners of domestic brands of transport, which are distinguished by a minimum number of additional functions. The following schemes are in great demand:

• Sound signaling devices of turns and inclusion of a manual brake;
• Battery and alternator operating modes indicator.

More experienced radio amateurs are engaged in equipping their car with parking sensors, electronic window lifters, automatic light sensors for controlling low beam headlights.

Homemade for beginners

Most beginner 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 novice 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 kits allow you to develop such skills:

• Reading circuit and wiring diagrams;
• Correct soldering;
• Adjustment and adjustment according to the finished method.

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

As a field of application of knowledge and experience, radio amateurs can design electronic toys using simpler circuits or converting industrial designs to their wishes and capabilities.

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

home workshop

For independent design of radio electronic devices, a certain minimum of tools, fixtures and measuring instruments is required:

• soldering iron;
• Side cutters;
• Tweezers;
• Screwdriver Set;
• pliers;
• Multifunction tester (avometer).

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

Most radio amateurs started their journey with the use of the simplest soldering iron 220V 25-40W, and from the measuring instruments in the home laboratory, the most massive Soviet tester Ts-20 was used. All this is enough for practicing with electricity, acquiring the necessary skills and experience.

It makes no sense for a novice radio amateur to buy an expensive soldering station if there is no necessary experience with a conventional soldering iron. Moreover, the possibility of using the station will not appear soon, but only after the lapse of 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 already versed in electronics, the oscilloscope is one of the most sought-after measurement tools.

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

Speaking about the home workshop at homemade, one cannot fail to mention the materials used for soldering. It's solder and flux. The most common solder is the POS-60 alloy, which has a low melting point and provides high soldering reliability. Most of the solders used for soldering various 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 a thin film of rosin formed after evaporation of the solvent (alcohol) exhibits good protective properties.

Important! When soldering electronic components, under no circumstances should active fluxes be used. This is especially true of soldering acid (zinc chloride solution), since even under normal conditions such a flux has a destructive effect on thin copper printed conductors.

For tinning highly oxidized leads, it is better to use an active acid-free flux LTI-120, which does not require rinsing.

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

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

Security measures

Doing electricity is associated with a risk to health and even life, especially if do-it-yourself electronics are designed with mains power. Homemade electrical devices should not use transformerless AC household power. 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 one. The voltage at its output will correspond to the mains voltage, but at the same time, reliable galvanic isolation will be provided.

For those who are just starting to take their first steps in electronics, it is important to start somewhere. Well, here are some ideas that might come in handy in the future and give you an idea of ​​how things should be done at the same time. What to choose if you want to make simple ones with your own hands? Here are options that can be used in everyday life.

Simple power control for smooth turning on of lamps

This type of device is widely used. The simplest is a conventional diode that is connected in series with the load. Such regulation can be used to extend the life of the incandescent lamp, as well as to prevent overheating of the soldering iron. They can also be used to change power over a wide range of values. First, there will be the simplest do-it-yourself electronic homemade products. You can see the diagrams here.

How to protect yourself from mains voltage fluctuations

This device disconnects the load if the mains voltage is out of range. As a rule, a deviation of up to 10% from the standard is considered within the normal range. But due to the peculiarities of the energy supply system in our country, such frameworks are not always respected. So, the voltage can be 1.5 times higher, or much lower than necessary. The result is often unpleasant - the equipment fails. Therefore, there is a need for a device that will turn off the load before something has time to burn out. But when creating such a homemade product, you must be careful, since the work will be carried out with considerable stress.

How to make a safety transformer

Transformerless power supplies are often used in various electronic designs. Typically, such devices have low power, and to avoid electrical shock, they are placed in an insulating plastic case. But sometimes they need to be configured, and then the protection is opened. To avoid possible injury, a safety isolation transformer is used. It will also be useful in the repair of such devices. Structurally, they consist of two identical windings, each of which is designed for the network. As a rule, the power of transformers of this type ranges from 60-100 W, these are the optimal parameters for setting up various electronics.

Simple emergency light source

What to do if it is necessary that in the event of a power outage, the illumination of some area is maintained? The answer to such challenges can be an emergency luminaire, made on the basis of a standard energy-saving lamp, the power of which does not exceed 11 watts. So if it is necessary that the light be somewhere in the corridor, utility room or workplace, this homemade product will come in handy. Usually, when voltage is present, they operate directly from the network. When it disappears, the lamp starts to function on battery power. When the mains voltage is restored, the lamp will work and the battery will automatically charge. The best do-it-yourself electronic homemade products were left at the end of the article.

Soldering iron boost controller

In cases where it is necessary to solder massive parts or the mains voltage often drops, the use of a soldering iron becomes problematic. And a step-up power regulator can help out of this situation. In these cases, the load (i.e. soldering iron) is powered by a rectified mains voltage. The change is carried out using an electrolytic capacitor, the capacity of which allows you to get a voltage of more than 1.41 network. So, with a standard voltage value of 220 V, it will give 310 V. And if there is a drop, say, to 160 V, it turns out that 160 * 1.41 \u003d 225.6 V, which will allow you to operate optimally. But this is just an example. You have the opportunity to make a scheme suitable specifically for your conditions.

The simplest twilight switch (photo relay)

As new parts are created, fewer and fewer components are now needed to make some kind of device. So, for a conventional twilight switch, only 3 of them are needed. Moreover, due to the versatility of the design, multi-purpose use is also possible: in an apartment building; to illuminate the porch or courtyard of a private dwelling, or even a separate room. Pointing to the features of such a design as a twilight switch, they also call it a “photo relay”. You can find many implementation schemes that were made either by amateurs or industrialists. They have their own set of positive and negative properties. As negative properties, either the need for a constant voltage source, or the complexity of the circuit itself is usually called. Also, when buying cheap and simple parts or whole sets, they often complain that they simply burn. The functionality of the scheme is based on three components:

1. Photocell. It is usually understood as photoresistors, phototransistors and photodiodes.
2. Comparator.
3. Triac, or relay.

When there is daylight, the resistance of the photocell is small, and does not exceed the response threshold. But as soon as it gets dark, the construction will be turned on at the same moment.

Conclusion

Here are some interesting do-it-yourself electronic homemade products you can do. The main thing in cases where something does not work out is to keep trying, and then everything will work out. And as you gain experience, you can move on to more complex schemes.

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.

[ Hide ]

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.

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 known, LDS with burnt filaments, it is necessary to feed the rectified current of the network 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

Do-it-yourself clock on IN-14 lamps

Do-it-yourself clock on IN-14 lamps

I have long wanted to post an article on the manufacture do-it-yourself clocks on IN-14 lamps, or as they say, a steampunk watch.

I will try step by step and dwelling on the key points to state only the most important. The clock indication is clearly visible both day and night, and they look very nice on their own, especially in a good wooden case. In general, let's get started.