Do-it-yourself electrical circuits. Useful and simple electronic devices and DIY projects. Power supply for analog and digital circuits
For those just starting to take their first steps into electronics, it is important to start somewhere. Well, we invite you to familiarize yourself with ideas that may come in handy in the future and at the same time give you an idea of how something should be done. 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 regulator for smooth switching of lamps
This type of device has found wide application. The simplest is a regular diode, which is connected in series with the load. Such regulation can be used to extend the life of an 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 DIY electronic crafts. You can see the diagrams here.
How to protect yourself from mains voltage fluctuations
This device turns off the load if the mains voltage is outside the permissible limits. As a rule, a deviation of up to 10% from the norm is considered normal. But due to the peculiarities of the energy supply system in our country, such limits are not always observed. 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 need to 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 injury, they are placed in an insulating plastic case. But sometimes they need to be configured, and then the security is broken. To avoid possible injury, use an isolating safety transformer. It will also be useful when repairing 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 lighting source
What should you do if you need to ensure that some area remains illuminated in the event of a power outage? The answer to such calls can be an emergency lamp made on the basis of a standard energy-saving lamp, the power of which does not exceed 11 Watts. So if you need light somewhere in the corridor, utility room or workplace, this homemade product will come in handy. Usually, if there is voltage, they operate directly from the mains. When it disappears, the lamp begins to function on battery power. When the mains voltage is restored, the lamp will work and the battery will automatically charge. The best electronic DIY projects have been left for the end of the article.
Boost power regulator for soldering iron
In cases where it is necessary to solder massive parts or the mains voltage often drops, using a soldering iron becomes problematic. And a step-up power regulator can help out of this situation. In these cases, the load (i.e., the soldering iron) is powered using rectified mains voltage. The change is carried out using an electrolytic capacitor, the capacitance of which allows you to obtain a voltage greater than 1.41 network voltage. So, with a standard voltage value of 220 V, it will give 310 V. And if there is a drop, say, to 160 V, then it will turn out that 160 * 1.41 = 225.6 V, which will allow for optimal operation. But this is just an example. You have the opportunity to make a scheme that is suitable specifically for your conditions.
The simplest twilight switch (photo relay)
As new parts are created, fewer components are now needed to make a device. So, for a regular twilight switch, only 3 of them are needed. Moreover, thanks to the versatility of the design, multi-purpose use is possible: in an apartment building; for lighting the porch or courtyard of a private home, or even a separate room. Pointing out the features of such a design as a twilight switch, it is also called 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. Negative properties are usually either the need for a constant voltage source or the complexity of the circuit itself. Also, when buying cheap and simple parts or entire sets, people often complain that they simply burn. The functionality of the scheme is based on three components:
- Photocell. It is usually understood as photoresistors, phototransistors and photodiodes.
- Comparator.
- Triac or relay.
When there is daylight, the resistance of the photocell is low and does not exceed the response threshold. But as soon as it gets dark, the structure will be turned on at that very moment.
Conclusion
Here are some interesting electronic crafts you can make with your own hands. The main thing in cases where something doesn’t work out is to keep trying, and then everything will work out. And after gaining experience, it will be possible to move on to more complex schemes.
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 you can put everything back together later.
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 operation current of the machine must be less than the operation current of the room machine. 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.
Every day there are more and more, many new articles appear, it is quite difficult for new visitors to immediately find their bearings and review at once everything that has already been written and previously posted.
I would really like to draw the attention of all visitors to individual articles that were posted on the site earlier. In order to avoid having to search for the necessary information for a long time, I will make several “entrance pages” with links to the most interesting and useful articles on individual topics.
Let's call the first such page "Useful electronic homemade products." Here we consider simple electronic circuits that can be implemented by people of any skill level. The circuits are built using a modern electronic base.
All information in the articles is presented in a very accessible form and to the extent necessary for practical work. Naturally, to implement such schemes you need to understand at least the basics of electronics.
So, a selection of the most interesting articles on the site on the topic "Useful electronic homemade products". The author of the articles is Boris Aladyshkin.
Modern electronics components greatly simplify circuit design. Even a regular 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 provides several diagrams of spot welding machines.
Using the described design, you can determine whether a mechanism located in another room or building is working or not. Information about the operation 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 turns off the load if the mains voltage exceeds acceptable limits.
The article discusses the circuit of a simple thermostat using an adjustable zener diode TL431.
An article about how to make a device for smoothly switching on lamps using the KR1182PM1 microcircuit.
Sometimes, when the voltage in the network is low or when 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 how you can replace a mechanical thermostat for an oil heating radiator.
Description of a simple and reliable thermostat circuit for a heating system.
The article describes a converter circuit made on a modern element base, containing a minimum number of parts and allowing significant power to be generated in the load.
An article about various ways to connect a load to a control unit on microcircuits using relays and thyristors.
Description of a simple control circuit for LED garlands.
The design of a simple timer that allows you to turn the load on and off at specified intervals. Working time and pause time do not depend on each other.
Description of the circuit and operating principle 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.
The electronic homemade section will be a good helper for you if you decide to become a self-taught electrician. Surely 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, a homemade battery charger.
Here you will find not only useful diagrams, but also electronic tricks and notes. Interesting electronic devices and circuits for them. From which you can make useful homemade products with your own hands.
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.
Electronic homemade products are made by hand at home; it can be a homemade machine or a small radio bug. All inventions involve electricity, so don't forget to follow safety rules!
Tags: ,Every modern home uses a variety of lighting devices. However, the most basic of them is the chandelier, which has a special elegance and beauty. In fact, a quality ceiling light has many distinctive qualities. Distinctive qualities of ceiling lamps. Firstly, as we said earlier, such devices always have an impeccable appearance. And this is not at all surprising, because ultra-modern devices...
Simple Logic Probe
A simple logic probe consists of two independent threshold devices, one of which is triggered by an input voltage corresponding to a logical "1", and the second - by a logical "O".
When the voltage at the probe input is between 0 and +0.4 V, transistors V7 and V8 are off, transistor V9 is off and V10 is on, the green LED V6 is on, indicating "0".
When the input voltage is from +0.4 to +2.3 V, transistors V7 and V8 are still closed, V9 is open, V10 is closed. LEDs do not light up. At a voltage above +2.3 V, transistors V8, V9 open and the red LED V5 lights up, indicating “1”. Diodes V1-V4 serve to increase the voltage at which the threshold device is activated, indicating “1”.
The current transfer coefficient of the transistors must be at least 400. The adjustment is made by selecting R5* and R7* according to the clear response of threshold devices at a voltage from +0.4 V to +2.4 V.
Network "CONTROL"
Typically, detector probes with neon bulbs are used to detect mains voltage. Alas, nowadays even such a sample is not easy to acquire. But it is quite simple to assemble a control device, the diagram of which is shown in the figure.
Advanced LED mains voltage indicator
I propose for repetition by radio amateurs an improved LED indicator of mains voltage, which differs from all previously published ones in being more noise-resistant. For example, the indicators shown in Fig. 1 and Fig. 2 are capable of giving false readings when the presence of voltage in a long cable is checked, and the cable has a broken phase wire. These indicators also give false readings when they are used to check the presence of voltage in network wiring with poor insulation - in basements, damp rooms, i.e. where there is low insulation resistance.
The proposed indicator (Fig. 3) is easy to manufacture and reliable in operation, free of false readings under any operating conditions. They can check both linear voltage 380 V and phase voltage. And it differs from all previous ones by using the KN102D dinistor in the circuit. Thanks to the latter, the indicator registers only the pure phase and does not respond to interference. The indicator uses a capacitor C1 - MBM 0.1 μF at 400 V and a resistor R1 - MLT 0.5.
Simple transistor tester
A simple transistor tester allows you to check the performance of bipolar transistors of n-p-n- and p-n-p-structures.
The transistor being tested, together with one of the V1 or V2 installed in the device (depending on the structure of the transistor being tested, determined by the position of switch S1), forms a multivibrator that generates low-frequency oscillations. Indicators of the presence of oscillations, and therefore the serviceability of the transistor being tested, are the LEDs V3 and V4, which flash at the frequency generated by the multivibrator.
This device can test transistors of low, medium and, in some cases, high power. Using resistor R1, the amplification properties of the low-power transistor being tested are assessed (approximately) - the greater the resistance of the introduced part of the resistor, at which the multivibrator is still operating, the higher the current transfer coefficient of this transistor. The device is powered by one 3336L battery.
Automatic light switch
The machine consists of a light sensor - a photoresistor and a photorelay made on transistors VI, V2, an actuator circuit on thyristors V4, V10 and a full-wave rectifier on diodes V6, V7. The machine works as follows. With decreasing illumination, the resistance of photoresistor R3 increases from 1...2 kOhm to 3...5 MOhm, which leads to an increase in the collector current of transistors VI and V2. As a result of this, thyristor V4 opens, the chain R7, SZ, V9 generates a pulse that opens thyristor V10, and the lighting lamps turn on. As the illumination of the photoresistor increases, its resistance decreases, and the collector current of transistor V2 also decreases, which leads to the blocking of thyristors V4 and V10. The lighting lamps go out, and the capacitor SZ is discharged through the diode V8 and resistors R5, R6 and R7. The switching threshold of the machine is set by resistor R1.
Details .
Variable resistor R1 type SPO-0.5, resistors type MLT-0.5; photoresistors of types SF2-2, SF2-5 or FSK-1; transistors - any low-frequency p-n-p structures with B> 50; capacitor C2 type MBM, MBGC, MBGP for a voltage of 400 V.
When setting up, it is necessary to select resistors R5-R7, achieving reliable opening of thyristor V10 at the photorelay operating threshold specified (by resistor R1).
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