Rotation speed regulator for 220V commutator motor. Speed regulators for maintaining power in engines. Features of speed control

When using an electric motor in various devices and tools, there is always a need to adjust the shaft rotation speed.

Making an electric motor speed controller yourself is not difficult. You just need to find a high-quality circuit, the design of which would be completely suitable for the features and type of a particular electric motor.

Using frequency converters

To adjust the speed of an electric motor operating from a network with a voltage of 220 and 380 Volts, frequency converters can be used. High-tech electronic devices allow, by changing the frequency and amplitude of the signal, to smoothly regulate the speed of the electric motor.

Such converters are based on powerful semiconductor transistors with wide-pulse modulators.

Converters, using a corresponding control unit on a microcontroller, allow you to smoothly change the engine speed.

High-tech frequency converters are used in complex and loaded mechanisms. Modern frequency regulators have several degrees of protection at once, including load, voltage current indicator and other characteristics. Some models are powered from a single-phase power supply of 220 Volts and can convert the voltage to three-phase 380 Volts. The use of such converters allows you to use asynchronous electric motors at home without the use of complex wiring diagrams.

Application of electronic regulators

The use of powerful asynchronous motors is impossible without the use of appropriate speed controllers. Such converters are used for the following purposes:

The operating scheme used by frequency converters is similar to that of most household appliances. Similar devices are also used in welding machines, UPSs, power supply for PCs and laptops, voltage stabilizers, lamp ignition units, as well as in monitors and LCD TVs.

Despite the apparent complexity of the circuit, making a speed controller for a 220 V electric motor will be quite simple.

How the device works

The operating principle and design of the engine speed controller is simple, therefore, having studied the technical aspects, it is quite possible to perform them yourself. Structurally, there are several The main components that make up the rotary controllers are:

The difference between asynchronous motors and standard drives is the rotation of the rotor with maximum power when voltage is applied to the transformer winding. At the initial stage, the current consumption and power of the motor increases to a maximum, which leads to a significant load on the drive and its rapid failure.

When the engine starts at maximum speed, a large amount of heat is released, which leads to overheating of the drive, windings and other drive elements. Thanks to the use of a frequency converter, it is possible to smoothly accelerate the engine, which prevents overheating and other problems with the unit. When using a frequency converter, the electric motor can be started at a speed of 1000 revolutions per minute, and subsequently smooth acceleration is ensured when 100-200 engine revolutions are added every 10 seconds.

Making homemade relays

Making a homemade speed controller for a 12 V electric motor will not be difficult. For this work you will need the following:

Wirewound resistors.
Switch for several positions.
Control unit and relay.

The use of wirewound resistors allows you to change the supply voltage and, accordingly, the engine speed. Such a regulator provides stepwise acceleration of the engine, has a simple design and can be made even by novice radio amateurs. Such simple homemade step regulators can be used with asynchronous and contact motors.

Operating principle of a homemade converter:

In the past, the most popular were mechanical regulators based on a variator or gear drive. However, they were not very reliable and often failed.

Homemade electronic regulators have proven themselves to be the best. They use the principle of changing step or smooth voltage, are durable, reliable, have compact dimensions and provide the ability to fine-tune the operation of the drive.

The additional use of triacs and similar devices in electronic regulator circuits allows for a smooth change in voltage power; accordingly, the electric motor will correctly gain speed, gradually reaching its maximum power.

To ensure high-quality regulation, variable resistors are included in the circuit, which change the amplitude of the incoming signal, providing a smooth or step change in the speed.

PWM transistor circuit

You can regulate the shaft rotation speed of low-power electric motors using a transistor bus and a series connection of resistors in the power supply. This option is easy to implement, but has low efficiency and does not allow smooth changes in engine rotation speed. Making your own speed controller for a 220 V brushed motor using a PWM transistor will not be particularly difficult.

The principle of operation of the transistor regulator:

Bus transistors used today have a sawtooth voltage generator with a frequency of 150 Hertz.
Operational amplifiers are used as a comparator.
The rotation speed is changed due to the presence of a variable resistor that controls the duration of the pulses.

Transistors have an even constant pulse amplitude, identical to the amplitude of the supply voltage. This allows you to adjust the speed of the 220 V engine and maintain the operation of the unit even when applying a minimum voltage to the transformer winding.

Thanks to the ability to connect a microcontroller to a PWM transistor, it is possible to automatically configure and adjust the operation of the electric drive. Such converter designs may have additional components that expand the functionality of the drive, ensuring operation in a fully automatic mode.

Introduction of automatic control systems

The presence of microcontroller control in regulators and frequency converters makes it possible to improve the operating parameters of the drive, and the motor itself can operate in a fully automatic mode, when the controller used smoothly or stepwise changes the rotation speed of the unit. Today, microcontroller control uses processors that have a different number of outputs and inputs. You can connect various electronic keys, buttons, various signal loss sensors, and so on to such a microcontroller.

You can find it on sale different types of microcontrollers, which are easy to use, guarantee high-quality adjustment of the operation of the converter and regulator, and the presence of additional inputs and outputs allows you to connect various additional sensors to the processor, upon the signal of which the device will reduce or increase the number of revolutions or completely stop the supply of voltage to the electric motor windings.

Today, various electric motor converters and controllers are available on the market. However, if you have even minimal skills in working with radio components and the ability to read diagrams, you can make such a simple device that will smoothly or stepwise change engine speed. Additionally, you can include a control triac rheostat and a resistor in the circuit, which will allow you to smoothly change the speed, and the presence of microcontroller control completely automates the use of electric motors.

Almost all household appliances and power tools use a commutator motor. Newer models of grinders, screwdrivers, hand routers, vacuum cleaners, mixers and others have engine speed control, but later models do not have this function. It is not always convenient to work with such tools and household appliances, and therefore there are speed controllers with power maintenance.

Types of engines and operating principles

Motors are divided into three types: commutator, asynchronous and brushless. Most power tools use the first type. This electric motor has a fairly compact size. Its power is significantly higher than that of asynchronous, and the price is quite low. As for asynchronous ones, this type is mainly used in the metalworking industry, and they are also widespread in coal mines. Quite rarely they can be found in everyday life.

The brushless electric motor is used where high speeds, precise positioning and small dimensions are needed. For example, in various medical equipment, aircraft modeling. The principle of operation is quite simple. If a rectangular frame, which has an axis of rotation, is placed between the pluses of a permanent magnet, then it will begin to rotate. The direction depends on the direction of the current in the frame. This type contains an armature and a stator. The armature rotates, but the stator stands still. As a rule, there is not one frame at anchor, but 4.5 or more.

An asynchronous motor works on a different principle. Thanks to the effect of an alternating magnetic field in the stator coils, it is driven into rotation. If you delve deeper into the course of physics, you can remember that a kind of magnetic field is created around the conductor through which the current passes, causing the rotor to rotate.

The principle of operation of the brushless type is based on turning on the windings so that the magnetic fields of the stator and rotor are orthogonal to each other, and the torque is regulated by a special driver.

The figure clearly shows that in order to move the rotor it is necessary to perform the necessary commutation, but it is not possible to regulate the speed. However, the brushless motor can rev up very quickly.

Commutator motor design

A commutator motor consists of a stator and a rotor. The rotor is the part that

rotates, but the stator is stationary. Another component of the electric motor is graphite brushes, through which current flows to the armature. Depending on the configuration, Hall sensors may be present, which make it possible to smoothly start and adjust the speed. The higher the applied voltage, the higher the speed. This type can operate on either AC or DC power.

According to the classification, commutator motors can be divided into those that operate on alternating current and direct current. They can also be divided according to the type of winding excitation: motors with parallel, series and mixed (parallel-series) excitation.

Types of adjustment

There are quite a few options for speed control. Here are the main ones:

Power supply with adjustable output voltage.
Factory adjustment devices that initially come with the electric motor.
Push-button regulators and standard regulators that simply limit the voltage.

These types of adjustments are bad because as the voltage decreases or increases, the power also drops. In some power tools this is acceptable, but, as practice shows, in most cases this is unacceptable due to a strong drop in power and, accordingly, efficiency.

The most acceptable option would be a regulator based on a triac or thyristor. Not only does such a regulator not reduce power when the voltage decreases, it also allows for smoother starting and speed control. In addition, such a scheme can be made with your own hands. Below is a picture of the speed control with power maintenance. The circuit is based on a BTA 41,800 V triac.

All ratings of electrical elements are indicated in the diagram. This is the circuit after assembly, it works quite stably and provides smooth adjustment of the brushed motor. When the output voltage decreases, the power does not decrease, which is a significant plus.

If desired, you can assemble the speed controller of a 220 V brushed motor with your own hands. This circuit is assembled on the basis of a VTA26-600 triac, which must first be installed on a radiator, since this element gets quite hot under load.

It is possible to connect an electric motor with a power not exceeding 4 kW to the finished circuit.

The diagram looks like this.

It can successfully cope with the adjustment of power tools such as a drill, grinder, circular saw, and jigsaw. If desired, you can use the circuit as a power regulator for heating elements, heaters, and as a dimmer. The disadvantages include the impossibility of adjusting the power of devices powered by direct current.

DC Power Regulators

Sometimes there is a need to adjust the speed of a brushed DC motor.

If the consumer does not have a lot of power, then it is possible to connect a variable resistor in series, but then the efficiency of such a regulator will drop sharply. There are schemes with which it is possible to regulate the speed quite smoothly without reducing efficiency. Such a regulator is suitable for changing the brightness of various lamps, supply voltage not exceeding 12 V. This circuit also acts as a speed stabilizer; when the mechanical load on the shaft changes, the speed remains unchanged.

This 12V DC motor speed controller circuit is quite suitable for regulating and stabilizing the speed of motors with a current not exceeding 5 A. This circuit includes a bipolar transistor driver and a 7555 timer, which ensures stable operation and smooth regulation speed. The price of the parts is quite low, which is a definite plus. You can also assemble a 12 V electric motor speed controller with your own hands.

Asynchronous motor and speed controller

As a rule, this type is used in various industries, ranging from mines to metalworking industries. For example, in coal mines, to smoothly start conveyor belts, an APM starter is used, which has a built-in thyristor device that allows the conveyor to start smoothly. An asynchronous single-phase motor is also used in cars, stove fans, motors that drive wipers, and household fans powered by a voltage of 220 V. In a car, motors operate on a constant voltage of 12 volts, but they do not provide for smooth starting.

To regulate the speed of an asynchronous motor, so-called frequency converters are used. These converters allow you to radically change the shape and frequency of the signal. As a rule, such converters are assembled on the basis of powerful semiconductor transistors and pulse modulators, and all elements are controlled by a PWM controller.

It should be remembered: the smoother the engine acceleration, the less overload it experiences. This applies to gearboxes, conveyors, powerful pumps, and elevators. Here is one circuit diagram of a 220 V asynchronous motor speed controller.

Using this circuit, you can regulate the speed of engines whose power does not exceed 1 thousand watts. When assembling this circuit, there are nuances that must be taken into account:

Due to significant heating, the diode bridge and power transistors must be installed on a radiator. If you intend to connect a motor with a power of up to 400 W, then it is not necessary to install a temperature sensor, and you can use an optocoupler for control.

To increase the service life of various types of engines, it is recommended to use speed controllers, which solve a large number of problems.

When starting the electric motor, the current consumption exceeds 7 times, which contributes to premature failure of the electrical and mechanical parts of the motor. To prevent this, you should use an electric motor speed controller. There are many factory-made models, but in order to make such a device yourself, you need to know the principle of operation of the electric motor and how to regulate rotor speed.

General information

AC electric motors have become widespread in many areas of human activity, namely asynchronous models. The main purpose of the engine as an electric machine is transformation of electrical energy into mechanical energy. Asynchronous in translation means non-simultaneous, since the rotor speed differs from the frequency of the alternating voltage (U) in the stator. There are two types of asynchronous motors based on the type of power supply:

Single-phase.
Three-phase.

Single-phase ones are used for household needs, and three-phase ones are used in production. Three-phase asynchronous motors (hereinafter referred to as TAM) use two types of rotors:

closed;
phase

Closed-circuit motors make up about 95% of all motors used and have significant power (from 250 W and above). The phase type is structurally different from the IM, but is used quite rarely compared to the first. The rotor is a cylindrical steel figure that is placed inside the stator, with a core pressed onto its surface.

Squirrel cage and wound rotors

Highly conductive copper (for high-power machines) or aluminum rods (for lower-power machines) soldered or poured into the surface of the core and short-circuited at the ends with two rings play the role of electromagnets with poles facing the stator. The winding rods do not have any insulation, since the voltage in such a winding is zero.

More commonly used for mid-power motor cores, aluminum has low density and high electrical conductivity.

To reduce higher harmonics of electromotive force (EMF) and eliminate magnetic field pulsation the rotor rods have a certain calculated angle of inclination relative to the axis of rotation. If a low-power electric motor is used, the grooves are closed structures that separate the rotor from the gap in order to increase the inductive component of the resistance.

The rotor in the form of a phase design or type is characterized by a winding, its ends are connected in a star type and attached to slip rings (on the shaft), along which graphite brushes slide. To eliminate eddy currents, the surface of the windings is covered with an oxide film. In addition, a resistor is added to the rotor winding circuit, which allows you to change the active resistance (R) of the rotor circuit to reduce the values of inrush currents (Ip). Starting currents negatively affect the electrical and mechanical parts of the electric motor. Variable resistors used to regulate Ip:

Metal or stepped with manual switching.
Liquid (due to immersion to the depth of the electrodes).

Graphite brushes are subject to wear, and some models are equipped with a squirrel-cage design that lifts the brushes and closes the rings after the motor starts. IMs with a wound rotor are more flexible in terms of regulation of Ip.

Design features

An asynchronous motor does not have pronounced poles, unlike a DC electric motor. Number of poles determined by the number of coils in the windings fixed part (stator) and connection method. In an asynchronous machine with 4 coils, a magnetic flux passes through. The stator is made of special steel sheets (electrical steel), which reduce eddy currents to zero, at which significant heating of the windings occurs. It leads to a massive interturn short circuit.

The iron ore or rotor core is pressed directly onto the shaft. There is a minimum air gap between the rotor and stator. The rotor winding is made in the form of a “squirrel cage” and is made of copper or aluminum rods.

In electric motors with a power of up to 100 kW, aluminum, which has low density, is used to fill the grooves of the rotor core. But despite this device, engines of this type get hot. To solve this problem fans are used for forced cooling, which are mounted on the shaft. These engines are simple and reliable. However, motors consume a large current when starting, 7 times the rated current. Because of this, they have a low starting torque, since most of the electrical energy goes to heating the windings.

Electric motors, which have an increased starting torque, differ from ordinary asynchronous motors in the design of the rotor. The rotor is made in the form of a double “squirrel cage”. These models are similar to the phase types of rotor manufacturing. It consists of an inner and outer “squirrel cage”, and the outer one is the starting one and has a large active and small reactive R. The outer one has a slight active and high reactive R. As the rotation speed increases, I switches to the inner cage and operates in the form of a squirrel-cage rotor.

Principle of operation

When I flows through the stator winding, a magnetic flux (F) is created in each of them. These F are shifted by 120 degrees relative to each other. The resulting F is rotating, creating electromotive force (EMF) in aluminum or copper conductors. As a result of this, a starting magnetic moment of the electric motor is created, and the rotor begins to rotate. This process is also called slip (S) in some sources, showing the frequency difference n1 of the electromagnetic field of the starter, which becomes greater than the frequency obtained when rotor n2 rotates. It is calculated as a percentage and has the form: S = ((n1-n2)/n1) * 100%.

Scheme 1 - Thyristor speed control of a commutator motor without loss of power.

This circuit performs regulation by opening or closing thyristors (triacs) during a phase transition through the neutral. To correctly control a commutator motor, the following methods of modifying circuit 1 are used:

Installation of LRC protective circuits consisting of capacitors, resistors and chokes.
Adding capacitance at the input.
The use of thyristors or triacs, the current of which exceeds the rated value of the motor current in the range of 3..8 times.

This type of regulator has advantages and disadvantages. The first include low cost, low weight and dimensions. The second ones include the following:

application for low power motors;
there is noise and jerking of the motor;
when using a circuit based on triacs, a constant U hits the motor.

This type of regulator is installed in fans, air conditioners, washing machines and electric drills. Performs its functions perfectly, despite its shortcomings.

Transistor type

Another name for a transistor-type regulator is an autotransformer or PWM regulator (scheme 2). It changes the value of U according to the principle of pulse width modulation (PWM) using an output stage that uses IGBT transistors.

Scheme 2 - Transistor PWM speed controller.

Switching of transistors occurs at a high frequency and thanks to this it is possible to change the width of the pulses. Consequently, the value of U will also change. The longer the pulse and the shorter the pause, the higher the value of U and vice versa. The positive aspects of using this variety are as follows:

Low weight of the device with small dimensions.
Quite low cost.
At low speeds there is no noise.
Control via low U values (0..12 V).

The main disadvantage of the application is that the distance to the electric motor should be no more than 4 meters.

Frequency regulation

Scheme 3 - Frequency speed controller.

A specialized inverter has its advantages and disadvantages. The advantages are the following:

Blood pressure control without human intervention.
Stability.
Additional features.

It is possible to control the operation of the electric motor under certain conditions, as well as protection against overloads and short-circuit currents. In addition, it is possible to expand the functionality by connecting digital sensors, monitoring operating parameters and using a PID controller. The disadvantages include limitations in frequency control and a fairly high cost.

For three-phase IM, frequency control devices are also used (Scheme 4). The regulator has three phases at the output for connecting an electric motor.

Scheme 4 - Inverter for a three-phase motor.

This option also has its strengths and weaknesses. The first include the following: low cost, choice of power, wide range of frequency regulation, as well as all the advantages of single-phase frequency converters. Among all the negative aspects, the main ones can be identified: preliminary selection and heating during startup.

DIY making

If there is no opportunity or desire to purchase a factory-type regulator, then you can assemble it yourself. Although regulators of the "tda1085" type have proven themselves very well. To do this, you need to familiarize yourself with the theory in detail and start practicing. Triac circuits are very popular, in particular the speed controller of a 220V asynchronous motor (diagram 5). It's not difficult to make. It is assembled using a VT138 triac, which is well suited for these purposes.

Scheme 5 - A simple speed controller on a triac.

This regulator can also be used to adjust the speed of a 12-volt DC motor, as it is quite simple and universal. The speed is regulated by changing the parameters P1, which determines the phase of the incoming signal, which opens the transition of the triac.

The operating principle is simple. When the engine starts, it slows down, the inductance changes downward and contributes to an increase in U in the “R2->P1->C2” circuit. When C2 is discharged, the triac opens for some time.

There is another scheme. It works a little differently: by providing a reverse type of energy flow, which is optimally beneficial. The circuit includes a fairly powerful thyristor.

Scheme 6 - Design of a thyristor regulator.

The circuit consists of a control signal generator, an amplifier, a thyristor and a circuit section that functions as a rotor rotation stabilizer.

The most universal circuit is a regulator based on a triac and dinistor (scheme 7). It is able to smoothly reduce the shaft rotation speed, reverse the motor (change the direction of rotation) and reduce the starting current.

The principle of operation of the circuit:

C1 is charged until U breakdown of dinistor D1 through R2.
When D1 breaks, it opens the junction of triac D2, which is responsible for controlling the load.

The load voltage is directly proportional to the frequency component when D2 opens, which depends on R2. The circuit is used in vacuum cleaners. It contains universal electronic control, as well as the ability to easily connect 380 V power. All parts should be placed on a printed circuit board made using laser-iron technology (LUT). You can find out more about this board manufacturing technology on the Internet.

Thus, when choosing an electric motor speed controller, you can buy a factory one or make it yourself. Making a homemade regulator is quite simple, since if you understand the principle of operation of the device, you can easily assemble it. In addition, you should follow safety rules when installing parts and when working with electricity.

The motor from a washing machine, which is great for homemade items, has too high speeds and a short lifespan at maximum speeds. Therefore, I use a simple homemade speed controller (without loss of power). The scheme was tested and showed excellent results. The speed is adjustable from approximately 600 to max.

The potentiometer is electrically isolated from the network, which increases the safety of using the regulator.

The triac must be placed on the radiator.

Almost any optocoupler (2 pcs), but EL814 has 2 counter LEDs inside, and is suitable for this circuit.

A high-voltage transistor can be installed, for example, IRF740 (from a computer's power supply), but it would be a pity to install such a powerful transistor in a low-current circuit. Transistors 1N60, 13003, KT940 work well.

Instead of the KTs407 bridge, a 1N4007 bridge, or any one with >300V, and a current of >100mA, is quite suitable.

Signet in .lay5 format. The signet is drawn “View from the M2 side (soldering)”, so When outputting to a printer, it must be mirrored. Color M2 = black, background = white, do not print other colors. The outline of the board (for cutting) is made on the M2 side, and will indicate the boundaries of the board after etching. It should be removed before sealing parts. A drawing of parts from the mounting side has been added to the signet for transfer to the signet. It then takes on a beautiful and finished look.

Adjustment from 600 rpm is suitable for most homemade products, but for special cases a circuit with a germanium transistor is proposed. The minimum speed was reduced to 200.

The minimum speed was 200 rpm (170-210, the electronic tachometer does not measure well at low speeds), the T3 transistor was installed GT309, it is direct conduction, and there are many of them. If you put MP39, 40, 41, P13, 14, 15, then the speed should decrease further, but I no longer see the need. The main thing is that such transistors are like dirt, unlike MP37 (see forum).

Soft start works great, True, the motor shaft is empty, but due to the load on the shaft during start-up, I will select R5 if necessary.

R5 = 0-3k3 depending on the load;; R6 = 18 Ohm - 51 Ohm - depending on the triac, I don’t have this resistor now;; R4 = 3k - 10k - T3 protection;; RP1 = 2k-10k - speed controller, connected to the network, protection from the operator's mains voltage is required!!!. There are potentiometers with a plastic axis, it is advisable to use them!!!This is a big drawback of this scheme, and if there is no great need for low speeds, I advise you to use V17 (from 600 rpm).

C2 = soft start, = delay time for turning on the motor;; R5 = charge C2, = charge curve slope, = motor acceleration time;; R7 - C2 discharge time for the next soft start cycle (at 51k this is approximately 2-3 seconds)

List of radioelements

Designation	Type	Denomination	Quantity	My notepad
T1	Triac	BT139-600	1	To notepad
T2	Dinistor		1	To notepad
VD	Diode bridge	KTs407A	1	To notepad
VD4	Rectifier diode	1N4148	1	To notepad
C2	Capacitor	220 uF x 4 V	1	To notepad
C1	Capacitor	100 nF x 160 V	1	To notepad
R1	Resistor	3.3 kOhm 0.5W	1	To notepad
R2	Resistor	330 Ohm 0.5W	1	To notepad
R3	Resistor	470 kOhm 0.125W	1	To notepad
R4	Resistor	200 Ohm 0.125W	1	To notepad
R5	Resistor	200 Ohm 0.125W	1	To notepad
V1	Optocoupler	PC817	2	To notepad
T3	Bipolar transistor	GT309G	1	To notepad
C2a	Capacitor	47 uF x 4 V	1

Any modern power tool or household appliance uses a commutator motor. This is due to their versatility, i.e. the ability to operate on both alternating and direct voltage. Another advantage is the efficient starting torque.

However, the high speed of the commutator motor does not suit all users. For a smooth start and the ability to change the speed of rotation, a regulator was invented, which is quite possible to make with your own hands.

Operating principle and types of commutator motors

Each electric motor consists of a commutator, stator, rotor and brushes. The principle of its operation is quite simple:

In addition to the standard device, there are also:

Regulator device

There are many schemes of such devices in the world. Nevertheless, they can all be divided into 2 groups: standard and modified products.

Standard device

Typical products are distinguished by ease of manufacture of the idynistor and good reliability when changing engine speed. As a rule, such models are based on thyristor regulators. The operating principle of such schemes is quite simple:

Thus, the speed of the commutator motor is adjusted. In most cases, a similar scheme is used in foreign household vacuum cleaners. However, you should know that such a speed controller does not have feedback. Therefore, when the load changes, you will have to adjust the speed of the electric motor.

Changed schemes

Of course, the standard device suits many fans of speed controllers to “dig” into the electronics. However, without progress and improvement of products, we would still be living in the Stone Age. Therefore, more interesting schemes are constantly being invented, which many manufacturers are happy to use.

The most commonly used are rheostat and integral regulators. As the name implies, the first option is based on a rheostat circuit. In the second case, an integral timer is used.

Rheostatic ones are effective in changing the number of revolutions of the commutator motor. High efficiency is due to power transistors, which take part of the voltage. Thus, the current flow is reduced and the motor works with less effort.

Video: speed control device with power maintenance

The main disadvantage of this scheme is the large amount of heat generated. Therefore, for smooth operation, the regulator must be constantly cooled. Moreover, the cooling of the device must be intensive.

A different approach is implemented in an integral regulator, where an integral timer is responsible for the load. As a rule, transistors of almost any type are used in such circuits. This is due to the fact that it contains a microcircuit with large output current values.

If the load is less than 0.1 ampere, then all the voltage goes directly to the microcircuit, bypassing the transistors. However, for the regulator to operate effectively, it is necessary that there be a voltage of 12V at the gate. Therefore, the electrical circuit and the supply voltage itself must correspond to this range.

Overview of typical circuits

You can regulate the rotation of the shaft of a low-power electric motor by connecting a power resistor in series with no. However, this option has very low efficiency and the inability to smoothly change speed. To avoid such a nuisance, you should consider several regulator circuits that are used most often.

As you know, PWM has a constant pulse amplitude. In addition, the amplitude is identical to the supply voltage. Consequently, the electric motor will not stop even when running at low speeds.

The second option is similar to the first. The only difference is that an operational amplifier is used as the master oscillator. This component has a frequency of 500 Hz and produces triangular-shaped pulses. Adjustment is also carried out using a variable resistor.

How to make it yourself

If you don’t want to spend money on purchasing a ready-made device, you can make it yourself. This way, you can not only save money, but also gain useful experience. So, to make a thyristor regulator you will need:

soldering iron (to check functionality);
wires;
thyristor, capacitors and resistors;
scheme.

As can be seen from the diagram, the regulator controls only 1 half-cycle. However, for testing performance on a regular soldering iron, this will be quite enough.

If you don’t have enough knowledge to decipher the diagram, you can familiarize yourself with the text version:

The use of regulators allows for more economical use of electric motors. In certain situations, such a device can be made independently. However, for more serious purposes (for example, monitoring heating equipment), it is better to purchase a ready-made model. Fortunately, there is a wide selection of such products on the market, and the price is quite affordable.