If it became necessary to regulate the speed of a motor connected to a 220 V network, we recommend that you assemble such a simple circuit. This motor speed controller is distinguished by low cost (a microcircuit on Aliexpress costs about 100 rubles), current feedback, and phase control of an AC electric motor.
AC motor controller circuit
The U2008B driver is designed to control phases and is made using bipolar technology. This allows you to control the current load level, as well as perform phase control compensation.
AC Motor Speed Controller Specifications
- Power: 220V AC
- Load power: up to 500 W
- Soft start motor
The TIC226 triac requires a heat sink for a higher load. Up to 100 watts is not necessary. You can replace it with any other, for example the popular B138-600. If you notice, jumper J1 is installed on the printed circuit board: load current compensation or soft start. The trimming resistor PR1 sets the range limits, and the external variable P1 directly controls the speed of rotation of the connected motor.
When using an electric motor in various devices and tools, it always becomes necessary to adjust the speed of rotation of the shaft.
It is not difficult to make an electric motor speed controller on your own. It is only necessary to find a high-quality circuit, the device of which would be completely suitable for the features and type of a particular electric motor.
Use of frequency converters
Frequency converters can be used to adjust the speed of an electric motor operating from a network with a voltage of 220 and 380 volts. High-tech electronic devices allow you to smoothly adjust the speed of the electric motor by changing the frequency and amplitude of the signal.
Such converters are based on powerful semiconductor transistors with wide-pulse modulators.
Converters using the appropriate control unit on the 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 by a single-phase voltage of 220 volts and can convert the voltage to three-phase 380 volts. The use of such converters allows the use of 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 operation scheme used by frequency converters is similar to that of most household appliances. Similar devices are also used in welding machines, UPS, PC and laptop power supplies, voltage stabilizers, lamp igniters, as well as monitors and LCD TVs.
Despite the apparent complexity of the circuit, it will be quite simple to make a 220 V electric motor speed controller.
The principle of operation of the device
The principle of operation and the design of the engine speed controller are simple, therefore, having studied the technical points, it is quite possible to carry them out on your own. Structurally, there are several the main components that make up the rotation regulators:
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 indicators of the consumed current and the power of the motor increase to a maximum, which leads to a significant load on the drive and its rapid failure.
When starting the engine at maximum speed, a large amount of heat is generated, which leads to overheating of the drive, winding 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 rpm, and subsequently smooth acceleration is provided when 100–200 engine revolutions are added every 10 seconds.
Making homemade relays
It will not be difficult to make a homemade 12 V electric motor speed controller. For this to work, you will need the following:
- Wirewound resistors.
- Multi-position switch.
- Control unit and relay.
The use of wire resistors allows you to change the supply voltage, respectively, and the engine speed. Such a regulator provides stepwise acceleration of the engine, has a simple design and can be performed even by novice radio amateurs. Such simple homemade step controllers can be used with asynchronous and contact motors.
The principle of operation of a homemade converter:
In the past, mechanical regulators based on a variator or gear drive were the most popular. However, they did not differ in due reliability and often failed.
Homemade electronic regulators have proven themselves from the best side. They use the principle of changing step or smooth voltage, they 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 the circuits of electronic regulators makes it possible to ensure a smooth change in the voltage power, respectively, the electric motor will pick up speed correctly, gradually reaching its maximum power.
To ensure high-quality adjustment, variable resistors are included in the circuit, which change the amplitude of the incoming signal, providing a smooth or step change in the number of revolutions.
Circuit on a PWM transistor
It is possible to regulate the speed of rotation of the shaft for low-power electric motors using a bus-transistor and a series connection of resistors in the power supply. This option is easy to implement, but has a low efficiency and does not allow you to smoothly change the engine speed. It will not be particularly difficult to make a 220 V collector motor speed controller using a PWM transistor with your own hands.
The principle of operation of the regulator on the transistor:
- Bus transistors used today have a sawtooth voltage generator with a frequency of 150 Hertz.
- Operational amplifiers are used as a comparator.
- Changing the rotation speed is carried out due to the presence of a variable resistor that controls the duration of the pulses.
Transistors have a flat constant amplitude of pulses, identical to the amplitude of the supply voltage. This allows you to adjust the speed of the 220 V motor and maintain the operation of the unit even when the minimum voltage is applied to the transformer winding.
Due to the possibility of connecting the microcontroller to a PWM transistor, it is possible to automatically tune 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 fully automatic mode, when the controller used smoothly or stepwise changes the speed of the unit. Today, microcontroller control uses processors that have a different number of outputs and inputs. Various electronic keys, buttons, various signal loss sensors, and so on can be connected to such a microcontroller.
On sale you can find various types of microcontrollers, which are easy to use, guarantee a high-quality adjustment of the operation of the converter and the regulator, and the presence of additional inputs and outputs allows you to connect various additional sensors to the processor, on the signal of which the device will reduce or increase the number of revolutions, or completely stop supplying voltage to the motor windings.
Today, various converters and motor controllers are on sale. However, if you have even minimal skills in working with radio components and the ability to read circuits, 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 fully automates the use of electric motors.
Collector motors can often be found in household electrical appliances and power tools: a washing machine, grinder, drill, vacuum cleaner, etc. Which is not at all surprising, because collector motors allow you to get both high speeds and high torque (including high starting torque ) - which is what is needed for most power tools.
At the same time, collector motors can be powered by both direct current (in particular, rectified current) and alternating current from a household network. To control the speed of rotation of the rotor of the collector motor, speed controllers are used, and they will be discussed in this article.
First, let's recall the device and the principle of operation of the collector engine. The commutator motor necessarily includes the following parts: a rotor, a stator and a brush-collector switching unit. When power is applied to the stator and the rotor, their magnetic fields begin to interact, the rotor eventually begins to rotate.
Power is supplied to the rotor through graphite brushes that are tightly attached to the collector (to the collector lamellae). To change the direction of rotation of the rotor, it is necessary to change the phasing of the voltage on the stator or on the rotor.
The rotor and stator windings may be fed from different sources, or may be connected in parallel or in series with each other. This is how collector motors of parallel and series excitation differ. It is collector motors of series excitation that can be found in most household electrical appliances, since such inclusion makes it possible to obtain an overload-resistant motor.
Speaking of speed controllers, first of all we will focus on the simplest thyristor (triac) circuit (see below). This solution is used in vacuum cleaners, washing machines, grinders, and shows high reliability when working in AC circuits (especially from a household network).
This circuit works quite unpretentiously: at each period of the mains voltage, it is charged through a resistor to the unlocking voltage of the dinistor connected to the control electrode of the main key (triac), after which it opens and passes current to the load (to the collector motor).
By adjusting the charging time of the capacitor in the triac opening control circuit, the average power supplied to the engine is regulated, and the speed is adjusted accordingly. This is the simplest regulator without current feedback.
The triac circuit is similar to the usual one, there is no feedback in it. In order for current feedback to appear, for example, to maintain acceptable power and prevent overloads, additional electronics are needed. But if we consider options from simple and unpretentious circuits, then a triac circuit is followed by a rheostat circuit.
The rheostat circuit allows you to effectively control the speed, but leads to the dissipation of a large amount of heat. It requires a radiator and efficient heat dissipation, and this is energy loss and low efficiency in the end.
More efficient controller circuits on special thyristor control circuits or at least on an integrated timer. The switching of the load (collector motor) on alternating current is carried out by a power transistor (or thyristor), which opens and closes one or more times during each period of the mains sinusoid. This regulates the average power supplied to the engine.
The control circuit is powered by 12 volts DC from its own source or from a 220 volt network through a damping circuit. Such schemes are suitable for controlling powerful motors.
The principle of regulation with microcircuits at direct current is of course. A transistor, for example, opens at a strictly specified frequency of a few kilohertz, but the duration of the open state is adjustable. So, by turning the knob of the variable resistor, the speed of rotation of the rotor of the collector motor is set. This method is useful for keeping low speeds of the commutator motor under load.
Better control is precisely DC regulation. When the PWM operates at a frequency of about 15 kHz, by adjusting the pulse width, the voltage is controlled at approximately the same current. Say, by adjusting the constant voltage in the range from 10 to 30 volts, they get different revolutions at a current of about 80 amperes, achieving the required average power.
If you want to make a simple regulator for a collector motor with your own hands without any special requests for feedback, then you can choose a thyristor circuit. All you need is a soldering iron, a capacitor, a dinistor, a thyristor, a pair of resistors and wires.
If you need a better regulator with the ability to maintain stable speed under a dynamic load, take a closer look at the regulators on microcircuits with feedback that can process the signal from the tachogenerator (speed sensor) of the collector motor, as is implemented, for example, in washing machines.
Andrey Povny
For a smooth increase and decrease in the speed of rotation of the shaft, there is a special device - a speed controller for a 220v electric motor. Stable operation, no voltage interruptions, long service life are the advantages of using a 220, 12 and 24 volt engine speed controller.
- Application area
- Choose a device
- FC device
- Device types
- triac device
Why do you need a frequency converter
The function of the regulator is to invert the voltage of 12.24 volts, ensuring smooth start and stop using pulse-width modulation.
Speed controllers are part of the structure of many devices, as they provide electrical control accuracy. This allows you to adjust the speed to the desired value.
Application area
The DC motor speed controller is used in many industrial and domestic applications. For example:
- heating complex;
- equipment drives;
- welding machine;
- electric ovens;
- vacuum cleaners;
- Sewing machines;
- washing machines.
Choose a device
In order to select an effective regulator, it is necessary to take into account the characteristics of the device, the features of the purpose.
- For collector motors, vector controllers are common, but scalar ones are more reliable.
- An important selection criterion is power. It must correspond to the permissible on the used unit. And it is better to exceed for the safe operation of the system.
- The voltage must be within acceptable wide ranges.
- The main purpose of the regulator is to convert the frequency, so this aspect must be selected according to the technical requirements.
- You also need to pay attention to the service life, dimensions, number of inputs.
FC device
- AC motor natural controller;
- drive unit;
- additional items.
The 12 V engine speed controller circuit is shown in the figure. The speed is controlled by a potentiometer. If the input receives pulses with a frequency of 8 kHz, then the supply voltage will be 12 volts.
The device can be purchased at specialized points of sale, or you can make it yourself.
When starting a three-phase motor at full power, current is transferred, the action is repeated about 7 times. The strength of the current bends the motor windings, heat is generated for a long time. The converter is an inverter that provides energy conversion. The voltage enters the regulator, where 220 volts are rectified using a diode located at the input. Then the current is filtered by means of 2 capacitors. PWM is formed. Further, the pulse signal is transmitted from the motor windings to a certain sinusoid.
There is a universal 12v device for brushless motors.
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The circuit consists of two parts - logical and power. The microcontroller is located on the chip. This scheme is typical for a powerful engine. The uniqueness of the regulator lies in its application with various types of engines. The power supply of the circuits is separate, the key drivers require 12V power supply.
Device types
triac device
The simister (triac) device is used to control lighting, the power of heating elements, and the speed of rotation.
The triac controller circuit contains a minimum of the details shown in the figure, where C1 is a capacitor, R1 is the first resistor, R2 is the second resistor.
With the help of the converter, the power is regulated by changing the time of the open triac. If it is closed, the capacitor is charged by the load and resistors. One resistor controls the amount of current, and the second regulates the rate of charge.
When the capacitor reaches the voltage limit of 12V or 24V, the key is activated. The simister goes into the open state. When the mains voltage passes through zero, the simister is locked, then the capacitor gives a negative charge.
Converters on electronic keys
Common thyristor regulator with a simple operation scheme.
Thyristor, works in an alternating current network.
A separate type is the AC voltage stabilizer. The stabilizer contains a transformer with multiple windings.
To a voltage source of 24 volts. The principle of operation is to charge the capacitor and the locked thyristor, and when the capacitor reaches the voltage, the thyristor sends current to the load.
Proportional signal process
The signals arriving at the input of the system form a feedback. Let's take a closer look at the microcircuit.
The TDA 1085 chip shown above provides 12v, 24v motor feedback control without power loss. It is obligatory to have a tachometer that provides feedback from the engine to the control board. The signal from the stakhodatchik goes to the microcircuit, which transfers the task to the power elements - to add voltage to the motor. When the shaft is loaded, the board adds voltage, and the power increases. Releasing the shaft, the voltage decreases. The revolutions will be constant, and the power moment will not change. The frequency is controlled in a large range. Such a 12, 24 volt motor is installed in washing machines.
With your own hands, you can make a device for a grinder, a wood lathe, a grinder, a concrete mixer, a straw cutter, a lawn mower, a wood splitter and much more.
Industrial regulators, consisting of 12, 24 volt controllers, are filled with resin, so they cannot be repaired. Therefore, a 12v device is often made independently. A simple option using the U2008B chip. The regulator uses current feedback or soft start. In the case of using the latter, elements C1, R4 are required, the jumper X1 is not needed, and vice versa with feedback.
When assembling the regulator, choose the right resistor. Since with a large resistor, there may be jerks at the start, and with a small resistor, the compensation will be insufficient.
Important! When adjusting the power controller, remember that all parts of the device are connected to the AC mains, so safety precautions must be observed!
Speed controllers for single-phase and three-phase motors 24, 12 volts are a functional and valuable device, both in everyday life and in industry.
The 220v collector motor speed controller circuit is of two types - standard and modified. It all depends directly on the regulator you are using.
- What are they needed for
- Speed controllers
- Standard schemes
- Modified circuit
What are they needed for
Many household appliances and power tools are not complete without a commutator motor. Such popularity of such an electric motor is due to its versatility.
For a collector motor, power supply from direct or alternating voltage can be used. An additional advantage is the effective starting torque. At the same time, operation from direct or alternating current of the electric motor is accompanied by a high frequency of rotation, which is not suitable for all users. To provide a smoother start and be able to adjust the speed, a speed controller is used. A simple regulator is quite possible to make with your own hands.
But before the circuit is discussed, you first need to understand the collector motors.
Collector motors
The design of any collector engine includes several basic elements:
- Collector;
- brushes;
- Rotor;
- Stator.
The operation of a standard commutator motor is based on the following principles.
- Current is supplied from a 220V voltage source. It is 220 volts that is the standard household voltage. For most appliances with electric motors, more than 220 volts is not required. Moreover, the current is supplied to the rotor and stator, which are connected to one another.
- As a result of the supply of current from a 220V source, a field is formed - a magnetic one.
- Under the influence of magnetic voltage, the rotation of the rotor begins.
- Brushes transfer voltage directly to the rotor of the device. Moreover, brushes are usually made on the basis of graphite.
- When the direction of the current in the rotor or stator is reversed, the shaft rotates in the opposite direction.
In addition to standard collector motors, there are other units:
- Sequential excitation electric motor. Their overload resistance is more impressive. Often found in household electrical appliances;
- Devices of parallel excitation. Their resistance does not differ in high rates, the number of turns is significantly greater than that of analogues;
- Single phase electric motor. It is very easy to make it yourself, the power is at a decent level, but the efficiency leaves much to be desired.
Speed controllers
Now back to the subject of the speed controller. All schemes available today can be divided into two broad categories:
- Standard speed controller circuit;
- Modified speed control devices.
Let's look at the features of the schemes in more detail.
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Standard schemes
The standard circuit of the collector electric motor controller has several features:
- Making a dinistor is not difficult. This is an important advantage of the device;
- The regulator has a high degree of reliability, which has a positive effect during its period of operation;
- Allows the user to comfortably change the engine speed;
- Most models are based on a thyristor regulator.
If you are interested in the principle of operation, then such a scheme looks quite simple.
- The current charge from the 220 volt source goes to the capacitor.
- Next comes the breakdown voltage of the dinistor through a variable resistor.
- After that, the test itself takes place.
- Triac opens. This element is responsible for the load.
- The higher the voltage, the more often the triac will open.
- Due to this principle of operation, the speed of the electric motor is regulated.
- The largest share of such motor adjustment schemes is accounted for by imported household vacuum cleaners.
- But when using a standard speed controller circuit, it is important to understand that it does not have feedback. And if changes occur with the load, the motor speed will have to be adjusted.
Modified circuit
Progress does not stand still. Despite the satisfactory performance of the standard engine speed control circuit, improvements have not hurt anyone yet.
The two most commonly used schemes are:
- Rheostatic. From the name it becomes obvious that the rheostat circuit is the basis here. Such regulators are highly effective when changing the number of revolutions of the electric motor. High efficiency indicators are explained by the use of power transistors, which select part of the voltage. So less current from the 220 volt source is supplied to the engine, it does not have to work with a large load. In this case, the scheme has a certain drawback - a large amount of heat generated. For the regulator to work for a long time, the power tool will require active constant cooling;
- Integral. For the operation of the integral control device, an integral timer is used, which is responsible for the load on the electric motor. All kinds of transistors can be involved here. This is due to the presence of a microcircuit in a design with large output current parameters. At a load of less than 0.1 amperes, all voltage goes directly to the microcircuit, bypassing the transistors. For the regulator to work effectively, a voltage of 12 volts is required at the gate. It follows from this that the electrical circuit and supply voltage must comply with this range.
A simple homemade regulator
If you do not want to buy a ready-made speed controller for the engine, it is quite possible to try to make it yourself to control the power of the device.
These are additional skills for you and a definite cost savings for the wallet.
To make a regulator, you will need:
- A set of wiring;
- soldering iron;
- Scheme;
- Capacitors;
- Resistors;
- Thyristor.
The wiring diagram will look like this.
According to the presented scheme, the power and speed regulator will control 1 half-cycle. It is decoded as follows.
- Power from a standard 220V network is supplied to the capacitor. 220 volts is a standard indicator of household outlets.
- The capacitor, having received a charge, enters into operation.
- The load is transferred to the bottom cable and resistors.
- The positive terminal of the capacitor is connected to the electrode of the thyristor.
- There is one sufficient charge of voltage.
- The second semiconductor opens.
- The thyristor passes through itself the load received from the capacitor.
- The capacitor discharges, and the half-cycle repeats again.
With a high power of the electric motor powered by direct or alternating current, the regulator makes it possible to use the unit more economically.
Homemade speed controllers have every right to exist. But when it comes to the need to use a motor controller for more serious equipment, it is recommended to buy a ready-made device. Let it cost more, but you will be sure of the performance and reliability of the unit.
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