8 basic do-it-yourself regulator circuits. Top 6 brands of regulators from China. 2 schemes. 4 Most Asked Questions about Voltage Regulators. + TEST for self-control

Voltage regulator- This is a specialized electrical device designed to smoothly change or adjust the voltage that feeds an electrical device.

Voltage regulator

Important to remember! Devices of this type are designed to change and adjust the supply voltage, not current. The current is regulated by the payload!

TEST:

4 questions about voltage regulators

1. What is the regulator for?

a) Change in voltage at the output of the device.

b) Breaking the electric circuit

1. What determines the power of the regulator:

a) From the input current source and from the executive body

b) On the size of the consumer

1. The main parts of the device, assembled by hand:

a) Zener diode and diode

b) Triac and thyristor

1. What are 0-5 volt regulators for:

a) Power the microcircuit with a stabilized voltage

b) Limit the current consumption of electric lamps

Answers.

2 The most common do-it-yourself pH schemes 0-220 volts

Scheme No. 1.

The simplest and most convenient voltage regulator to use is regulator on thyristors connected back to back. This will produce a sinusoidal output signal of the required magnitude.

The input voltage of up to 220V is supplied to the load through the fuse, and through the second conductor, through the power button, the sinusoidal half-wave enters the cathode and anode thyristors VS1 and VS2. And through the variable resistor R2, the output signal is adjusted. Two diodes VD1 and VD2 leave behind only a positive half-wave arriving at the control electrode of one of thyristors, which leads to its discovery.

Important! The higher the current signal on the thyristor key, the stronger it will open, that is, the more current it can pass through itself.

An indicator light is provided to control the input power, and a voltmeter is used to adjust the output power.

Scheme No. 2.

A distinctive feature of this circuit is the replacement of two thyristors with one triac. This simplifies the circuit, makes it more compact and easier to manufacture.

In the circuit, there is also a fuse and a power button, and an adjusting resistor R3, and it controls the base of the triac, this is one of the few semiconductor devices with the ability to work with alternating current. current passing through resistor R3, acquires a certain value, it will control the degree of opening triac. After that, it is rectified on the diode bridge VD1 and through the limiting resistor it enters the key electrode of the triac VS2. The remaining elements of the circuit, such as capacitors C1, C2, C3 and C4, serve to dampen the ripples of the input signal and filter it from extraneous noise and unregulated frequencies.

How to avoid 3 common mistakes when working with a triac.

1. The letter, after the code designation of the triac, indicates its maximum operating voltage: A - 100V, B - 200V, C - 300V, G - 400V. Therefore, you should not take a device with the letters A and B to adjust 0-220 volts - such a triac will fail.
2. The triac, like any other semiconductor device, gets very hot during operation, you should consider installing a radiator or an active cooling system.
3. When using a triac in load circuits with high current consumption, it is necessary to clearly select the device for the stated purpose. For example, a chandelier in which 5 light bulbs of 100 watts are installed will consume a total current of 2 amperes. When choosing from the catalog, it is necessary to look at the maximum operating current of the device. So triac The MAC97A6 is rated at only 0.4 amps and will not withstand such a load, while the MAC228A8 is capable of passing up to 8 A and will be suitable for this load.

3 Highlights in the manufacture of powerful pH and do-it-yourself current

The device controls loads up to 3000 watts. It is built on the use of a powerful triac, and it controls the shutter or key dinistor.

Dinistor- this is the same as a triac, only without a control output. If triac opens and begins to pass current through itself, when a control voltage appears on its base and remains open until it disappears, then dinistor will open if a potential difference appears between its anode and cathode above the opening barrier. It will remain unlocked until the current between the electrodes falls below the blocking level.

As soon as a positive potential hits the control electrode, it opens and passes an alternating current, and the stronger this signal is, the higher the voltage between its terminals, and hence at the load. To regulate the degree of opening, a decoupling circuit is used, consisting of a dinistor VS1 and resistors R3 and R4. This circuit sets the current limit on the key triac, and capacitors smooth out ripples on the input signal.

2 basic principles in the manufacture of PH 0-5 volts

1. To convert the input high potential to a low constant, special microcircuits of the LM series are used.
2. The chips are powered only by direct current.

Let us consider these principles in more detail and analyze a typical regulator circuit.

The LM series ICs are designed to step down high DC voltage to low values. To do this, there are 3 outputs in the device case:

• The first output is the input signal.
• The second output is the output signal.
• The third output is the control electrode.

The principle of operation of the device is very simple - the input high voltage of a positive value is fed to the input output and then converted inside the microcircuit. The degree of transformation will depend on the strength and magnitude of the signal on the control "leg". In accordance with the master pulse, a positive voltage will be created at the output from 0 volts to the limit for this series.

The input voltage, not higher than 28 volts and necessarily rectified, is supplied to the circuit. You can take it from the secondary winding of the power transformer or from a high voltage regulator. After that, a positive potential is applied to the output of the microcircuit 3. Capacitor C1 smoothes the ripple of the input signal. A variable resistor R1 of 5000 ohms sets the output signal. The higher the current that it passes through itself, the higher the microcircuit opens. The output voltage of 0-5 volts is taken from output 2 and through the smoothing capacitor C2 enters the load. The higher the capacitance of the capacitor, the smoother it is at the output.

Voltage regulator 0 - 220v

Top 4 stabilizing microcircuits 0-5 volts:

1. KR1157- a domestic microcircuit, with an input signal limit of up to 25 volts and a load current of not more than 0.1 amperes.
2. 142EN5A- a microcircuit with a maximum output current of 3 amperes, no more than 15 volts are applied to the input.
3. TS7805CZ- a device with permissible currents up to 1.5 amperes and increased input voltage up to 40 volts.
4. L4960- a pulse microcircuit with a maximum load current of up to 2.5 A. The input voltage should not exceed 40 volts.

pH on 2 transistors

This type is used in circuits of especially powerful regulators. In this case, the current to the load is also transmitted through the triac, but the key output is controlled through the cascade transistors. This is implemented as follows: a variable resistor regulates the current that enters the base of the first low-power transistor, and that through the collector-emitter junction controls the base of the second powerful transistor and already he opens and closes the triac. This implements the principle of very smooth control of huge currents on the load.

Answers to the 4 most frequently asked questions about regulators:

1. What is the tolerance of the output voltage? For factory-made instruments of large firms, the deviation will not exceed + -5%
2. What determines the power of the regulator? The output power directly depends on the power source and on the triac that switches the circuit.
3. What are 0-5 volt regulators for? These devices are most often used to power microcircuits and various circuit boards.
4. Why do you need a household regulator 0-220 volts? They are used to smoothly turn on and off household electrical appliances.

4 Do-it-yourself pH diagrams and connection diagram

Briefly consider each of the schemes, features, advantages.

Scheme 1.

A very simple circuit for connecting and smoothly adjusting the soldering iron. Used to prevent the soldering iron tip from burning and overheating. The scheme uses a powerful triac, which is controlled by a thyristor-variable chain resistor.

Scheme 2.

Scheme based on the use of a phase control chip of the type 1182PM1. It controls the degree of opening triac, which controls the load. They are used to smoothly control the degree of luminosity of incandescent bulbs.

Scheme 3.

The simplest scheme for regulating the incandescence of a soldering iron tip. Made in a very compact design using easily accessible components. One thyristor controls the load, the degree of inclusion of which is regulated by a variable resistor. There is also a diode to protect against reverse voltage. thyristor,

Chinese pH at 220 volts

Nowadays, goods from China have become quite a popular topic, and Chinese voltage regulators are not far behind the general trend. Consider the most popular Chinese models and compare their main characteristics.

There is an opportunity to choose any regulator according to your requirements and needs. On average, one watt of useful power costs less than 20 cents, and this is a very favorable price. But still, it is worth paying attention to the quality of parts and assembly, for goods from China it is still very low.

Devices that allow you to control the operation of electrical appliances, adjusting them to the optimal characteristics for the user, have become firmly established in everyday life. One such device is the power regulator. The use of such regulators is in demand when using electric heating and lighting devices and in devices with engines. The circuitry of regulators is diverse, so sometimes it is difficult to choose the best option for yourself.

The first developments of devices that changed the power supplied to the load were based on Ohm's law: electrical power is equal to the product of current and voltage or the product of resistance and current squared. On this principle, the device, called the rheostat, was designed. It is located both in series and in parallel with the connected load. By changing its resistance, the power is also regulated.

The current entering the rheostat is divided between it and the load. When connected in series, the current and voltage are controlled, and when connected in parallel, only the value of the potential difference. Depending on the material from which the resistance is made, rheostats can be:

According to the law of conservation of energy, the electrical energy taken cannot simply disappear, therefore, in resistors, power is converted into heat, and at a large value it must be removed from them. To ensure the withdrawal, cooling is used, which is performed by blowing or immersing the rheostat in oil.

The rheostat is a fairly versatile device.. Its only, but significant disadvantage is the release of heat, which does not allow the device to be made with small dimensions, if necessary, to pass a large amount of power through it. By controlling the strength of current and voltage, a rheostat is often used in low-power lines of household appliances. For example, in audio equipment for volume control. It is not difficult to make such a current regulator with your own hands, to a greater extent this applies to a wire rheostat.

For its manufacture, you will need a constant or nichrome wire, which is wound on a mandrel. Regulation of electric power occurs by changing the length of the wire.

Types of modern devices

The development of semiconductor technology has made it possible to control power using radio elements with an efficiency of eighty percent. This made it possible to comfortably use them in a network with a voltage of 220 volts, without requiring large cooling systems. And the appearance of integrated circuits made it possible to achieve miniature sizes of the entire regulator as a whole.

To date, the production produces the following types of devices:

In this case, the adjustment occurs regardless of the shape of the input signal. By their type of location, control devices are divided into portable and stationary. They can be performed both in an independent package and integrated into the equipment. The main parameters characterizing the regulators of electrical energy include:

• smooth adjustment;
• operating and peak input power;
• input working signal range;

Thus, a modern electric power regulator is an electronic circuit, the use of which allows you to control the amount of energy passed through it.

Thyristor control device

The principle of operation of such a device is not particularly complicated. The thyristor converter is mainly used to control low power devices. A typical thyristor power controller circuit consists directly of the thyristor itself, bipolar transistors and resistors that set their operating point, and a capacitor.

Transistors, working in the key mode, form a pulse signal. As soon as the voltage value on the capacitor is compared with the working one, the transistors open. The signal is applied to the control output of the thyristor, opening it as well. The capacitor is discharged and the key is locked. This is repeated in a cycle. The longer the delay, the less power is delivered to the load.

Advantages of this type of regulator is that it does not require tuning, and the disadvantage is excessive heating. To combat overheating of the thyristor, an active or passive cooling system is used.

This type of regulator is used to convert the power supplied to both household appliances (soldering iron, electric heater, spiral lamp) and industrial ones (soft start of powerful power plants). Switching circuits can be single-phase and three-phase. The most used: ku202n, VT151, 10RIA40M.

Triac power converter

A triac is a semiconductor device designed for use in an alternating current circuit. A distinctive feature of the device is that its outputs do not have a separation into anode and cathode. Unlike a thyristor, which only allows current to flow in one direction, triac conducts current in both directions. That is why it is used in AC networks.

An important difference between triac and thyristor circuits is that there is no need for a rectifier. The principle of operation is based on phase control, that is, on changing the moment of opening the triac relative to the transition of the alternating voltage through zero. Such a device allows you to control heaters, incandescent lamps, motor speed. The signal at the output of the triac has a sawtooth shape with a controlled pulse duration.

Self-manufacturing of this type of device is easier than thyristor. Medium power triacs of the type: BT137-600E, MAC97A6, MCR 22-6 have gained wide popularity. The power regulator circuit on a triac using such elements is easy to manufacture and does not require tuning.

Phase transformation method

The dimmer itself has a wide range of applications. One of the options for its use is to adjust the intensity of lighting. The electrical circuit of the device is most often implemented on specialized microcontrollers that use the built-in electronic voltage reduction circuit in their work. Because of this, dimmers are able to smoothly change power, but are sensitive to interference.

Phase power regulators are not stabilized using zener diodes, but thyristors operating in pairs are used as a stabilizer. The basis of their work lies in changing the opening angle of the key thyristor, as a result of which the load receives signals with the initial part of the half-cycle cut off, reducing the effective voltage value. To the disadvantages of dimmers refer to high ripple and low output power factor.

The most popular among radio amateurs are circuits designed to control the brightness of the lamp and change the power of the soldering iron. Such circuits are easy to repeat and can be assembled without the use of printed circuit boards by simple surface mounting.

Schemes made independently are in no way inferior in performance to factory ones, since they do not require settings and, with serviceable radio components, are immediately ready for use. In the absence of the opportunity or desire to make the device with your own hands from scratch, you can purchase kits for self-production. Such kits contain all the necessary radio elements, a printed circuit board and a diagram with assembly instructions.

Dominant schema

Such a device is easiest to assemble on a thyristor. The operation of the circuit is based on the ability of the thyristor to open when the input sinusoid passes through zero, as a result of which the signal is cut off and the voltage at the load changes.

The circuit for repeating a thyristor power controller is based on the use of a VS1 thyristor, which is KU202N. This radio element is made of silicon and has a p-n-p structure. It is used as a symmetrical switch of medium power signals and switching of power circuits on alternating current.

When a voltage of 220V is applied, the input signal is rectified and fed to the capacitor C1. As soon as the value of the voltage drop across C1 equals the value of the potential difference, at the point between the resistances R3 and R4, the bipolar transistors VT1 and VT2 open. The voltage level is limited by the Zener diode VD1. The signal is sent to the control output KU202N, and the capacitor C1 is discharged. When a signal occurs at the control output, the thyristor is unlocked. As soon as the capacitor is discharged, VT1 and VT2 are closed, respectively, and the thyristor is locked. At the next half-cycle of the input signal, everything repeats again.

KT814 and KT815 are used as transistors. Discharge time is adjustable with R5 and power too. The zener diode is used with a stabilization voltage of 7 to 14 volts.

Such a regulator can be used not only as a dimmer, but also to control the power of a collector motor. The dominant circuit can operate at currents up to 10 amperes, this value directly depends on the characteristics of the thyristor used, while it must be installed on the radiator.

Soldering iron heating controller

Soldering iron power control not only has a positive effect on its service life, preventing the tip and its internal elements from overheating, but also allows you to solder radio elements that are critical to the temperature of the device.

Devices for controlling the temperature of the soldering iron have been produced for a long time. One of its types was a domestic device, produced under the name "Additional device for electric soldering iron type P223". It allowed you to connect a low-voltage soldering iron to a 220V network.

The easiest way to perform a regulator for a soldering iron using a triac KU208G.

The power contacts are connected in series to the load. Therefore, the current flowing through the triac coincides with the load current. To control the key mode, a VS2 dinistor is used. Capacitor C1 is charged through resistors: R1 and R2. Operation indication is organized under VD1 and LED. Due to the fact that it takes time for the voltage across the capacitor to change, a phase shift occurs between the mains and capacitor voltages. By changing the value of the resistance R2, the phase shift is adjusted. The longer the capacitor charges, the less the triac is in the open state, and hence the power value is lower.

Such a regulator is designed to connect loads with a power of up to 300 watts. When using a soldering iron with a power of more than 100 watts, the triac should be installed on a radiator. The manufactured board can be easily placed on a textolite 25x30 mm in size and freely placed in an internal power outlet.

To control some types of household appliances (for example, a power tool or a vacuum cleaner), a triac-based power regulator is used. You can learn more about the principle of operation of this semiconductor element from the materials posted on our website. In this publication, we will consider a number of issues related to triac load power control circuits. As always, let's start with theory.

The principle of operation of the regulator on the triac

Recall that it is customary to call a triac a modification of a thyristor, which plays the role of a semiconductor switch with a non-linear characteristic. Its main difference from the basic device lies in the two-way conduction when switching to the "open" mode of operation, when current is applied to the control electrode. Due to this property, triacs do not depend on the polarity of the voltage, which allows them to be effectively used in circuits with alternating voltage.

In addition to the acquired feature, these devices have an important property of the base element - the ability to maintain conductivity when the control electrode is turned off. In this case, the "closing" of the semiconductor key occurs at the moment of the absence of a potential difference between the main terminals of the device. That is, when the alternating voltage passes the zero point.

An additional bonus from such a transition to the "closed" state is the reduction in the number of interference in this phase of operation. Note that a noise-free regulator can be designed to be driven by transistors.

Due to the properties listed above, it is possible to control the load power by phase control. That is, the triac opens every half cycle and closes when passing through zero. The delay time for turning on the "open" mode, as it were, cuts off part of the half-cycle, as a result, the shape of the output signal will be sawtooth.

In this case, the signal amplitude will remain the same, which is why such devices are incorrectly called voltage regulators.

Regulator circuit options

Here are some examples of circuits that allow you to control the load power using a triac, let's start with the simplest one.

Figure 2. Scheme of a simple power regulator on a triac powered by 220 V

Designations:

• Resistors: R1 - 470 kOhm, R2 - 10 kOhm,
• Capacitor C1 - 0.1 uF x 400 V.
• Diodes: D1 - 1N4007, D2 - any indicator LED 2.10-2.40 V 20 mA.
• Dinistor DN1 - DB3.
• Triac DN2 - KU208G, you can install a more powerful analogue of BTA16 600.

With the help of the DN1 dinistor, the D1-C1-DN1 circuit is closed, which puts DN2 in the “open” position, in which it remains until the zero point (the end of the half-cycle). The moment of opening is determined by the accumulation time on the capacitor of the threshold charge required to switch DN1 and DN2. The charge rate of C1 is controlled by the R1-R2 chain, the total resistance of which determines the moment of “opening” of the triac. Accordingly, the load power is controlled by means of a variable resistor R1.

Despite the simplicity of the circuit, it is quite effective and can be used as a dimmer for filament lighting fixtures or a soldering iron power regulator.

Unfortunately, the above circuit does not have feedback, therefore, it is not suitable as a stabilized collector motor speed controller.

Feedback Regulator Circuit

Feedback is necessary to stabilize the speed of the electric motor, which can change under the influence of the load. You can do this in two ways:

1. Install a tachometer that measures the number of revolutions. This option allows for fine adjustment, but it increases the cost of implementing the solution.
2. Track changes in voltage on the electric motor and, depending on this, increase or decrease the "open" mode of the semiconductor switch.

The latter option is much easier to implement, but requires a little adjustment to the power of the electric machine used. Below is a diagram of such a device.

Designations:

• Resistors: R1 - 18 kOhm (2 W); R2 - 330 kOhm; R3 - 180 Ohm; R4 and R5 - 3.3 kOhm; R6 - it is necessary to select how this is done will be described below; R7 - 7.5 kOhm; R8 - 220 kOhm; R9 - 47 kOhm; R10 - 100 kOhm; R11 - 180 kOhm; R12 - 100 kOhm; R13 - 22 kOhm.
• Capacitors: C1 - 22 uF x 50 V; C2 - 15 nF; C3 - 4.7 uF x 50 V; C4 - 150 nF; C5 - 100 nF; C6 - 1 uF x 50 V ..
• Diodes D1 - 1N4007; D2 - any indicator LED for 20 mA.
• Triac T1 - BTA24-800.
• Chip - U2010B.

This scheme provides a smooth start of the electrical installation and provides its protection against overload. Three operating modes are allowed (set by switch S1):

• A - When overloaded, LED D2 turns on, signaling an overload, after which the engine reduces speed to the minimum. To exit the mode, you must turn off and turn on the device.
• B - In case of overload, LED D2 turns on, the motor is switched to work with a minimum speed. To exit the mode, it is necessary to remove the load from the electric motor.
• C - Overload indication mode.

Setting up the circuit is reduced to the selection of resistance R6, it is calculated, depending on the power, of the electric motor according to the following formula:. For example, if we need to drive a 1500 W motor, then the calculation will be as follows: 0.25 / (1500 / 240) = 0.04 ohms.

For the manufacture of this resistance, it is best to use a nichrome wire with a diameter of 0.80 or 1.0 mm. Below is a table that allows you to select the resistance R6 and R11, depending on the engine power.

The given device can be used as a speed controller for motors of power tools, vacuum cleaners and other household equipment.

Regulator for inductive load

Those who attempt to drive an inductive load (such as a welding machine transformer) with the above circuits will be disappointed. The devices will not work, and the failure of the triacs is quite possible. This is due to the phase shift, which is why the semiconductor key does not have time to switch to the “open” mode during a short pulse.

There are two options for solving the problem:

1. Submission to the control electrode of a series of pulses of the same type.
2. Apply a constant signal to the control electrode until it passes through zero.

The first option is the most optimal. Here is a diagram where such a solution is used.

As can be seen from the following figure, which shows the oscillograms of the main signals of the power regulator, a burst of pulses is used to open the triac.

This device makes it possible to use semiconductor switch regulators to control an inductive load.

A simple do-it-yourself power regulator on a triac

At the end of the article, we give an example of a simple power regulator. In principle, any of the above schemes can be assembled (the most simplified version was shown in Figure 2). For this device, it is not even necessary to make a printed circuit board, the device can be assembled by surface mounting. An example of such an implementation is shown in the figure below.

You can use this regulator as a dimmer, as well as control powerful electric heating devices with it. We recommend choosing a circuit in which a semiconductor switch is used for control with characteristics corresponding to the load current.

Triacs are called a semiconductor device, on which there are 5 districts of transitions. Its most important quality is the ability to transmit a signal, both in forward and reverse directions.

The principle of operation of the triac power controller

They are used only in small electrical appliances due to the fact that they are extremely sensitive to electromagnetic waves, generate a lot of heat and are unable to operate at high AC frequencies. They are not used in large industrial units.

The device is easy to manufacture, does not require large financial costs and has a long service life. It can be easily applied in areas and devices where the disadvantages described above do not play a big role.

Many do not know what triac power controllers are for. But they are present in most home appliances such as hair dryers, vacuum cleaners, power tools and heating appliances.

The power regulator allows you to pass an electrical signal, with a frequency set by the user.

Instructions on how to make a triac regulator with your own hands

To date, it is not so easy to find a suitable power regulator, despite the low price, it is extremely problematic to get a triac that is completely suitable in terms of parameters.

Therefore, there is no other choice but to make it yourself. To do this, you need to consider a few simple basic regulator circuits, how they differ from each other and analyze the elementary base of each.

The device and circuits of simple regulators

The simplest circuit that can work under any load. Components are the simplest electronic components, and the control is carried out according to the phase-pulse principle.

The main elements of the scheme:

• triac VD4 10 A, 400 V
• dinistor VD3 32 V
• potentiometer R2

A current flows through R2 and R3, which accumulates a charge on the capacitor C1. After the charge reaches 32 V, the VD3 dinistor opens and the capacitor C1 starts to discharge through R4 and VD3. The energy will go to the triac VD4, it will open and let the current flow through the load.

The power is adjusted using the triac VD3 and the load R2. The value of the effect of the triac is constant and cannot be changed, the power is adjusted by changing the load resistance R2.

Elements VD1, VD2, R1 are optional in this circuit, but they allow you to ensure smooth and accurate changes in output power.

What elements will be needed

• Dinistor DB3;
• Triac TS106-10-4, VT136-600, 4-12A.
• Diodes VD1, VD2 1N4007;
• Resistances R1100 kOhm, R3 1 kOhm, R4 270 Ohm, R5 1.6 kOhm, potentiometer R2 100 kOhm;
• Capacitor C1 0.47 uF (operating voltage from 250 V).

This scheme is the most common and universal, there are many variations of it.

Assembly

By using this assembly plan, you will save your time. You need the exact parameters of the device for which the device will be manufactured.

Need to know:

Note!

• Number of phases. There may be one or three;
• The need for precise adjustment of the output power;
• Input voltage and current consumed by the load. Values ​​must be in Volts and Amps.

You must select the device type, either analog or digital. Select accessories according to the power of the device. On the network you can find various software that will help with the calculations.

Perform heat dissipation calculation. This is done quite simply: The voltage drop across the triac is multiplied by the rated current. The necessary data must be indicated in the characteristics of the triac.

Purchase the necessary elements, a printed circuit board and a heatsink. Route the tracks on the printed circuit board using a solvent. We must not forget about the fastening of the triac and the radiator. Solder all the elements as shown in the diagram. Pay special attention to the polarity of connecting diodes and triac.

Check the finished device with a multimeter in resistance mode. The characteristic must be identical to the original project.

Install the triac almost close to the radiator, but you need to provide thermal insulation between them. The screw to be fixed must be insulated with high quality. Make a plastic case for the device.

Note!

Place the resulting installation in a protective case. Set the potentiometer values ​​to the minimum values ​​and carry out a test run. With a multimeter we measure the voltage at the output, while smoothly turning the knob of the regulator;

If the result obtained does not correspond to the required, we adjust the power. If the device works as it should, you can connect the load to the output of the regulator.

Conclusion

A properly made triac power controller will serve reliably and require a small financial investment. Durability will please the most skeptical professionals. You can see the photo of home-made triac power controllers in the network and make sure that this device is worth manufacturing.

Photo triac power controller

Note!

In the article we will talk about how to make a triac power controller with your own hands. What is a simistor? This is a device built on a semiconductor crystal. It has as many as 5 p-n junctions, the current can pass both in the forward and in the opposite direction. But these elements are not widely used in modern industrial equipment, since they are highly sensitive to electromagnetic interference.

They also cannot operate at high current frequencies, they generate a large amount of heat if they switch large loads. Therefore, IGBT transistors and thyristors are used in industrial equipment. But triacs should not be overlooked either - they are cheap, they have a small size, and most importantly, a high resource. Therefore, they can be used where the disadvantages listed above do not play a big role.

How does a triac work?

You can meet today a triac power regulator in any household appliance - in grinders, screwdrivers, washing machines and vacuum cleaners. In other words, wherever there is a need for smooth adjustment of the engine speed.

The regulator works like an electronic key - it closes and opens at a certain frequency, which is set by the control circuit. When the device is unlocked, a half-wave of voltage passes through it. Therefore, a small fraction of the minimum power is delivered to the load.

Is it possible to do it yourself?

Many radio amateurs make their own triac power controllers for various purposes. With it, you can control the heating of the soldering tip. But, unfortunately, ready-made devices can be found on the market, but quite rarely.

They have a low cost, but often the devices do not meet the requirements that consumers demand. That is why it is much easier, it turns out, not to buy a ready-made regulator, but to make it yourself. In this case, you can take into account all the nuances of using the device.

Regulator circuit

Let's look at a simple triac power regulator that can be used with any load. The control is phase-pulse, all components are traditional for such structures. You need to apply the following elements:

1. Directly triac, rated for a voltage of 400 V and a current of 10 A.
2. Dinistor with an opening threshold of 32 V.
3. A variable resistor is used to control the power.

The current that flows through the variable resistor and resistance charges the capacitor with each half wave. As soon as the capacitor accumulates a charge and the voltage between its plates is 32 V, the dinistor will open. In this case, the capacitor is discharged through it and the resistance to the control input of the triac. The latter opens at the same time so that the current passes to the load.

To change the duration of the pulses, you need to select a variable resistor and the threshold voltage of the dinistor (but this is a constant value). Therefore, you have to "play" with the resistance of the variable resistor. In the load, the power turns out to be the resistance of the variable resistor. It is not necessary to use diodes and a fixed resistor, the circuit is designed to ensure accuracy and smoothness of power control.

How the device works

The current that flows through the dinistor is limited by a fixed resistor. It is with its help that the pulse length is adjusted. The fuse protects the circuit from short circuit. It should be noted that the dinistor in each half-wave opens to the same angle.

Therefore, there is no rectification of the flowing current, you can even connect an inductive load to the output. Therefore, a triac power regulator can also be used for a transformer. In order to select triacs, you need to take into account that for a load of 200 W, it is necessary that the current be equal to 1 A.

The diagram uses the following elements:

1. Dinistor type DB3.
2. Triacs of the type VT136-600, TS106-10-4 and similar ones with a current rating of up to 12 A.
3. Semiconductor germanium diodes - 1N4007.
4. Electrolytic capacitor for voltage over 250 V, capacitance 0.47 uF.
5. Variable resistor 100 kOhm, constant - from 270 Ohm to 1.6 kOhm (selected empirically).

Features of the regulator circuit

This scheme is the most common, but you can find small variations of it. For example, sometimes a diode bridge is placed instead of a dinistor. In some circuits, a chain of capacitance and resistance is found to suppress interference. There are more modern designs that use a control scheme on microcontrollers. When using such a circuit, you get fine current and voltage regulation in the load, but it is more difficult to implement.

Preparatory work

In order to assemble a triac power controller for an electric motor, you just need to follow this sequence:

1. First you need to determine the characteristics of the device that will be connected to the regulator. The characteristics include: the number of phases (either 3 or 1), the need for precise adjustment of power, voltage and current.
2. Now you need to select a specific type of device - digital or analog. After that, you can select the components according to the load power. In principle, special software can be used for simulation.
3. Calculate heat dissipation. To do this, multiply two parameters - the rated current (in Amperes) and the voltage drop across the triac (in Volts). All this data can be found among the characteristics of the element. As a result, you will get the power dissipation, expressed in watts. Based on this value, you need to select a radiator and a cooler (if necessary).
4. Purchase all the necessary items or prepare them if you have them.

Now you can proceed directly to the assembly of the device.

Regulator Assembly

Before you assemble a triac power controller according to the scheme, you need to perform a number of actions:

1. Route the tracks on the board and prepare the sites on which you want to install the elements. Provide space for mounting the triac and radiator in advance.
2. Install all the elements on the board and solder them. In the event that you do not have the opportunity to make a printed circuit board, surface mounting is allowed. The wires that connect all the elements should be as short as possible.
3. Pay attention to whether the polarity is observed when connecting the triac and diodes. If there is no marking, ring the elements with a multimeter.
4. Test the circuit using a multimeter in resistance measurement mode.
5. Fix the triac on the radiator, it is advisable to use thermal paste for better surface contact.
6. The whole circuit can be installed in a plastic case.
7. Set the variable resistor knob to the leftmost position and turn on the device.
8. Measure the voltage value at the output of the device. If you turn the knob of the resistor, the voltage should gradually increase.

As you can see, a do-it-yourself triac power controller is a useful design that can be used in everyday life with virtually no restrictions. The repair of this device is cheap, since the cost is quite low.