To perform many types of work on wood, metal or other types of materials, it is not high speeds that are required, but good traction. It would be more correct to say - the moment. It is thanks to him that the planned work can be completed efficiently and with minimal power losses. For this purpose, motors are used as a driving device. direct current(or collector), in which the supply voltage is rectified by the unit itself. Then, to achieve the required performance characteristics, it is necessary to adjust the speed of the commutator motor without loss of power.

Features of speed control

It is important to know, what each engine consumes when rotating not only active, but also reactive power. In this case, the level of reactive power will be higher, which is due to the nature of the load. In this case, the task of designing devices for regulating the rotation speed of commutator motors is to reduce the difference between the active and reactive power. Therefore, such converters will be quite complex, and it is not easy to make them yourself.

You can construct only some semblance of a regulator with your own hands, but there is no point in talking about saving power. What is power? In electrical terms, it is the current drawn multiplied by the voltage. The result will give a certain value that includes active and reactive components. To isolate only the active one, that is, to reduce losses to zero, it is necessary to change the nature of the load to active. Only semiconductor resistors have these characteristics.

Hence, it is necessary to replace the inductance with a resistor, but this is impossible, because the engine will turn into something else and obviously will not set anything in motion. The goal of lossless regulation is to maintain torque, not power: it will still change. Only a converter can cope with such a task, which will control the speed by changing the duration of the opening pulse of thyristors or power transistors.

Generalized controller circuit

An example of a controller that implements the principle of controlling a motor without power loss is a thyristor converter. These are proportional integral circuits with feedback that provide strict regulation characteristics, ranging from acceleration and braking to reverse. The most effective is pulse-phase control: the repetition rate of the unlocking pulses is synchronized with the network frequency. This allows you to maintain torque without increasing losses in the reactive component. The generalized diagram can be represented in several blocks:

• power controlled rectifier;
• rectifier control unit or pulse-phase control circuit;
• tachogenerator feedback;
• current control unit in the motor windings.

Before delving into a more precise device and principle of regulation, it is necessary to decide on the type of commutator motor. The control scheme for its performance characteristics will depend on this.

Types of commutator motors

At least two types of commutator motors are known. The first includes devices with an armature and an excitation winding on the stator. The second includes devices with an armature and permanent magnets. It is also necessary to decide, for what purpose is it necessary to design a regulator:

Motor design

Structurally, the engine is from washing machine“Indesit” is simple, but when designing a regulator for controlling its speed, it is necessary to take into account the parameters. Motors may have different characteristics, which is why the control will also change. The operating mode is also taken into account, which will determine the design of the converter. Structurally, the commutator motor consists from the following components:

• An armature, it has a winding laid in the grooves of the core.
• Collector, mechanical rectifier AC voltage network through which it is transmitted to the winding.
• Stator with field winding. It is necessary to create a permanent magnetic field, in which the anchor will rotate.

When the current in the motor circuit, connected according to the standard circuit, increases, the field winding is connected in series with the armature. With this inclusion, we also increase the magnetic field acting on the armature, which allows us to achieve linearity of characteristics. If the field remains unchanged, then it will be more difficult to obtain good dynamics, not to mention large power losses. Such engines are best used on low speeds, since they are more convenient to control at small discrete movements.

By organizing separate control of the excitation and armature, it is possible to achieve high positioning accuracy of the motor shaft, but the control circuit will then become significantly more complicated. Therefore, we will take a closer look at the controller, which allows you to change the rotation speed from 0 to the maximum value, but without positioning. This might come in handy, if a full-fledged drilling machine with the ability to cut threads will be made from a washing machine engine.

Scheme selection

Having found out all the conditions under which the motor will be used, you can begin to manufacture a speed controller for the commutator motor. You should start by choosing a suitable scheme that will provide you with all the necessary characteristics and capabilities. You should remember them:

• Speed ​​regulation from 0 to maximum.
• Providing good torque at low speeds.
• Smooth speed control.

Looking at many schemes on the Internet, we can conclude that few people are creating such “units”. This is due to the complexity of the control principle, since it is necessary to organize the regulation of many parameters. Thyristor opening angle, control pulse duration, acceleration-deceleration time, torque rise rate. These functions are handled by a circuit on the controller that performs complex integral calculations and transformations. Let's consider one of the schemes that is popular among self-taught craftsmen or those who simply want to put it to good use. old engine from the washing machine.

All our criteria are met by the circuit for controlling the rotation speed of a commutator motor, assembled on specialized chip TDA 1085. This is a completely ready driver for controlling motors that allow you to adjust the speed from 0 to the maximum value, maintaining torque through the use of a tachogenerator.

Design Features

The microcircuit is equipped with everything necessary for high-quality engine control in various speed modes, from braking to acceleration and rotation at maximum speed. Therefore, its use greatly simplifies the design, while simultaneously doing all universal drive, since you can choose any speed with a constant torque on the shaft and use it not only as a drive for a conveyor belt or drilling machine, but also for moving the table.

The characteristics of the microcircuit can be found on the official website. We will indicate the main features that will be required to construct the converter. These include: an integrated frequency-to-voltage conversion circuit, an acceleration generator, a device soft start, Tacho signal processing unit, current limiting module, etc. As you can see, the circuit is equipped with a number of protections that will ensure stable operation of the regulator in different modes.

The figure below shows a typical circuit diagram for connecting a microcircuit.

The scheme is simple, so it is quite reproducible with your own hands. There are some features that include limit values ​​and speed control method:

If you need to organize a motor reverse, then for this you will have to supplement the circuit with a starter that will switch the direction of the excitation winding. You will also need a zero speed control circuit to give permission for reverse. Not shown in the picture.

Control principle

When the rotation speed of the motor shaft is set by a resistor in output circuit 5, a sequence of pulses is formed at the output to unlock the triac by a certain angle. The speed of rotation is monitored by a tachogenerator, which occurs in digital format. The driver converts the received pulses into an analog voltage, which is why the shaft speed is stabilized at a single value, regardless of the load. If the voltage from the tachogenerator changes, the internal regulator will increase the level of the output control signal of the triac, which will lead to an increase in speed.

The microcircuit can control two linear accelerations, allowing you to achieve the dynamics required from the engine. One of them is installed on the Ramp 6 pin of the circuit. This regulator is used by washing machine manufacturers themselves, so it has all the advantages to be used for domestic purposes. This is ensured by the presence of the following blocks:

Usage similar scheme provides full control of the commutator motor in any mode. Thanks to forced acceleration control, it is possible to achieve the required acceleration speed to a given rotation speed. Such a regulator can be used for all modern washing machine motors used for other purposes.

The electric motor is necessary for smooth acceleration and braking. Such devices are widely used in industry. With their help, the rotation speed of the fans is changed. 12 Volt motors are used in control systems and automobiles. Everyone has seen the switches that change the rotation speed of the stove fan in cars. This is one of the types of regulators. It's just not designed to run smoothly. The rotation speed changes in steps.

Application of frequency converters

Frequency converters are used as speed regulators and 380V. These are high-tech electronic devices that allow you to radically change the characteristics of the current (signal shape and frequency). They are based on powerful semiconductor transistors and a pulse-width modulator. All operation of the device is controlled by a microcontroller unit. The rotation speed of the engine rotor changes smoothly.

Therefore, they are used in loaded mechanisms. The slower the acceleration, the less load the conveyor or gearbox will experience. All frequency generators are equipped with several degrees of protection - for current, load, voltage and others. Some models of frequency converters are powered from single-phase and turn it into three-phase. This allows you to connect asynchronous motors at home without using complex circuits. And there will be no loss of power when working with such a device.

For what purposes are regulators used?

In the case of asynchronous motors, speed controllers are needed for:

1. Significant energy savings. After all, not every mechanism requires high speed rotation of the motor - sometimes it can be reduced by 20-30%, and this will reduce energy costs by half.
2. Protection of mechanisms and electronic circuits. Using frequency converters, you can control temperature, pressure and many other parameters. If the engine operates as a pump drive, then a pressure sensor must be installed in the container into which it pumps air or liquid. And when the maximum value is reached, the motor will simply turn off.
3. Performing a soft start. There is no need to use additional electronic devices - everything can be done by changing the settings of the frequency converter.
4. Reduced maintenance costs. With the help of such speed controllers for 220V electric motors, the risk of failure of the drive and individual mechanisms is reduced.

The circuit according to which frequency converters are built is widespread in many household appliances. Something similar can be found in uninterruptible power supplies, welding machines, voltage stabilizers, power supplies for computers, laptops, phone chargers, ignition units for backlight lamps of modern LCD TVs and monitors.

How do rotary controls work?

You can make an electric motor speed controller with your own hands, but to do this you will need to study all the technical aspects. Structurally, several main components can be distinguished, namely:

1. Electric motor.
2. Microcontroller control system and converter unit.
3. Drive and mechanisms associated with it.

At the very beginning of operation, after voltage is applied to the windings, the motor rotor rotates with maximum power. It is this feature that distinguishes asynchronous machines from others. To this is added the load from the mechanism that is driven. As a result, on initial stage power and current consumption increase to the maximum.

A lot of heat is generated. Both the windings and wires overheat. Using a frequency converter will help get rid of this. If you install a soft start, then up to maximum speed(which is also regulated by the device and may not be 1500 rpm, but only 1000), the engine will not accelerate immediately, but over 10 seconds (increase 100-150 rpm every second). At the same time, the load on all mechanisms and wires will decrease significantly.

Homemade regulator

You can make your own speed controller for a 12V electric motor. This will require a multi-position switch and wirewound resistors. With the help of the latter, the supply voltage (and with it the rotation speed) changes. Similar systems can be used for asynchronous motors, but they are less efficient. Many years ago, mechanical regulators were widely used - based on gear drives or variators. But they were not very reliable. Electronic means perform much better. After all, they are not so bulky and allow you to fine-tune the drive.

To make an electric motor rotation controller, you will need several electronic devices, which can either be purchased in a store or removed from old inverter devices. The VT138-600 triac shows good results in the circuits of such electronic devices. To make the adjustment, you will need to include a variable resistor in the circuit. With its help, the amplitude of the signal entering the triac changes.

Implementation of a management system

To improve the parameters of even the most simple device, you will need to include microcontroller control in the electric motor speed controller circuit. To do this, you need to select a processor with a suitable number of inputs and outputs - for connecting sensors, buttons, electronic keys. For experiments, you can use the AtMega128 microcontroller - the most popular and easiest to use. You can find many schemes using this controller in the public domain. Finding them yourself and applying them in practice is not difficult. In order for it to work correctly, you will need to write an algorithm into it - responses to certain actions. For example, when the temperature reaches 60 degrees (measured on the radiator of the device), the power should be turned off.

Finally

If you decide not to make a device yourself, but to purchase a ready-made one, then pay attention to the main parameters, such as power, type of control system, operating voltage, frequencies. It is advisable to calculate the characteristics of the mechanism in which it is planned to use the motor voltage regulator. And don’t forget to compare it with the parameters of the frequency converter.

Diagrams and review of 220V electric motor speed controllers. Dimmer for electric motor 220 volts

Electric motor speed controller 220V | 2 Schemes

A high-quality and reliable rotation speed controller for single-phase commutator electric motors can be made using common parts in literally 1 evening. This circuit has a built-in overload detection module, provides a soft start of the controlled motor and a motor rotation speed stabilizer. This unit operates with voltages of both 220 and 110 volts.

Regulator technical parameters

• Supply voltage: 230 volts AC
• regulation range: 5…99%
• load voltage: 230 V / 12 A (2.5 kW with radiator)
• maximum power without radiator 300 W
• low level noise
• speed stabilization
• soft start
• board dimensions: 50×60 mm

Schematic diagram

The control system module circuit is based on a PWM pulse generator and a motor control triac - a classic circuit design for such devices. Elements D1 and R1 ensure that the supply voltage is limited to a value that is safe for powering the generator microcircuit. Capacitor C1 is responsible for filtering the supply voltage. Elements R3, R5 and P1 are a voltage divider with the ability to regulate it, which is used to set the amount of power supplied to the load. Thanks to the use of resistor R2, which is directly included in the input circuit to the m/s phase, the internal units are synchronized with the VT139 triac.

The following figure shows the arrangement of elements on a printed circuit board. During installation and startup, attention should be paid to ensuring safe operating conditions - the regulator is powered by a 220V network and its elements are directly connected to the phase.

Increasing regulator power

In the test version, a BT138/800 triac with a maximum current of 12 A was used, which makes it possible to control a load of more than 2 kW. If you need to control even larger load currents, we recommend installing the thyristor outside the board on a large radiator. You should also remember about making the right choice fuse FUSE depending on the load.

In addition to controlling the speed of electric motors, you can use the circuit to adjust the brightness of lamps without any modifications.

2shemi.ru

Electric motor speed controller: how to make

Smooth engine operation, without jerks or power surges, is the key to its durability. To control these indicators, an electric motor speed controller is used for 220V, 12V and 24V; all of these frequencies can be made with your own hands or you can buy a ready-made unit.

Why do you need a speed controller?

Engine speed controller, frequency converter is a device based on powerful transistor, which is necessary in order to invert the voltage, as well as ensure smooth stopping and starting of an asynchronous motor using PWM. PWM – wide-pulse control of electrical devices. It is used to create a specific sinusoid of alternating and direct current.

The simplest example of a converter is a conventional voltage stabilizer. But the device under discussion has a much wider range of operation and power.

Frequency converters are used in any device that is powered by electrical energy. Governors provide extremely precise electrical motor control so that engine speed can be adjusted up or down, maintaining revs at the desired level, and protecting instruments from sudden revving. In this case, the electric motor uses only the energy needed to operate, instead of running it at full power.

Why do you need a speed controller for an asynchronous electric motor:

1. To save energy. By controlling the speed of the motor, the smoothness of its start and stop, strength and speed, you can achieve significant savings in personal funds. As an example, reducing speed by 20% can result in energy savings of 50%.
2. The frequency converter can be used to control process temperature, pressure or without the use of a separate controller;
3. No additional controller required for soft start;
4. Maintenance costs are significantly reduced.

The device is often used for a welding machine (mainly for semi-automatic machines), an electric stove, a number of household appliances (vacuum cleaner, sewing machine, radio, washing machine), home heater, various ship models, etc.

Operating principle of the speed controller

The speed controller is a device consisting of the following three main subsystems:

1. AC motor;
2. Main drive controller;
3. Drive and additional parts.

When the AC motor is started at full power, current is transferred with the full power of the load, this is repeated 7-8 times. This current bends the motor windings and generates heat that will be generated for a long time. This can significantly reduce engine longevity. In other words, the converter is a kind of step inverter that provides double energy conversion.

Depending on the incoming voltage, the frequency regulator of the speed of a three-phase or single-phase electric motor rectifies the current of 220 or 380 volts. This action is carried out using a rectifying diode, which is located at the energy input. Next, the current is filtered using capacitors. Next, PWM is generated, the electrical circuit is responsible for this. Now the windings of the induction motor are ready to transmit the pulse signal and integrate them into the desired sine wave. Even with a microelectric motor, these signals are issued, literally, in batches.

How to choose a regulator

There are several characteristics by which you need to choose a speed controller for a car, machine electric motor, or household needs:

1. Control type. For commutator motors, there are regulators with a vector or scalar control system. The former are more often used, but the latter are considered more reliable;
2. Power. This is one of the most important factors to select an electrical frequency converter. It is necessary to select a frequency generator with a power that corresponds to the maximum permissible on the protected device. But for a low-voltage motor it is better to choose a regulator more powerful than the permissible watt value;
3. Voltage. Naturally, everything here is individual, but if possible you need to buy a speed controller for an electric motor whose circuit diagram has a wide range permissible stresses;
4. Frequency range. Frequency conversion is the main task of this device, so try to choose a model that will best suit your needs. Let's say, for a manual router, 1000 Hertz will be enough;
5. According to other characteristics. This is the warranty period, the number of inputs, the size (there is a special attachment for desktop machines and hand tools).

At the same time, you also need to understand that there is a so-called universal rotation regulator. This is a frequency converter for brushless motors.

There are two parts in this circuit - one is logical, where the microcontroller is located on the chip, and the second is power. Basically, such an electrical circuit is used for a powerful electric motor.

Video: electric motor speed controller with SHIRO V2

How to make a homemade engine speed controller

You can make a simple triac motor speed controller, its diagram is presented below, and the price consists only of parts sold in any electrical store.

To work, we need a powerful triac of the BT138-600 type, it is recommended by a radio engineering magazine.

In the described circuit, the speed will be adjusted using potentiometer P1. Parameter P1 determines the phase of the incoming pulse signal, which in turn opens the triac. This scheme can be used both in field farming and at home. You can use this regulator for sewing machines, fans, tabletop drilling machines.

The principle of operation is simple: at the moment when the motor slows down a little, its inductance drops, and this increases the voltage in R2-P1 and C3, which in turn leads to a longer opening of the triac.

A thyristor feedback regulator works a little differently. It allows energy to flow back into the energy system, which is very economical and beneficial. This electronic device is intended to be connected to electrical diagram powerful thyristor. His diagram looks like this:

Here, to supply direct current and rectify, a control signal generator, an amplifier, a thyristor, and a speed stabilization circuit are required.

www.asutpp.ru

Making a simple dimmer with your own hands

A dimmer is an electronic device that allows you to control the voltage in the load, and therefore the power. Adjustment can be implemented in several ways. But the most common is the phase method, the essence of which is to control in time the moment of unlocking the power switch (transistor, thyristor). In AC networks, dimmers based on a symmetrical thyristor (triac) in the form of a simple and inexpensive design have proven themselves best. How to make a dimmer with your own hands from available parts is described in this article.

Scheme and principle of its operation

Almost all modern triac dimmers for household use have a common element base. All other parts of the circuit perform additional functions: they provide indication, contribute to stable work at lower voltage, make the adjustment smoother and so on.

Let's look at the operating principle of a triac regulator using the example of the most common 220-volt dimmer circuit shown in the figure. The main element of the circuit is triac VS1. It passes current in both directions when an unlocking pulse appears on the control electrode. Power electrodes VS1 are connected in series with the load. Therefore, the load current is equal to the triac current. In the power switch control circuit there is a dinistor VS2, the open and closed state of which depends on the voltage on its electrodes. Elements R1, R2 and C1 participate in the charging circuit of capacitor C1. Diode VD1 and LED form the on-state indicator circuit. When the dimmer is turned on, the triac is closed and the load current does not flow. At the moment of the appearance of the next positive or negative half-wave mains voltage current begins to flow through resistors R1 and R2. Capacitor C1 charges at a rate determined by the resistance of the indicated resistors. Due to the fact that the voltage on the capacitor cannot change instantly, some phase shift is formed between the voltage in the network and on C1. When the capacitor reaches a voltage equal to the response voltage of the dinistor (32V), the latter opens, which leads to the appearance of a pulse on the control electrode VS1 and its unlocking. Current flows through the load. The triac is in the open state until the end of the half-wave (change of polarity) of the mains voltage. Then the process is repeated.

Due to the change in resistance R2, the phase shift increases (decreases). The greater the resistance, the longer the capacitor will charge and the shorter the open time of the triac. In other words, turning the control knob changes the power in the load.

Printed circuit board and assembly parts

In order to assemble the presented dimmer with your own hands, you will need the following radio components:

• C1 – non-polar metal film capacitor with a capacity of 0.022-0.1 µF-400V;
• R1 – resistor 4.7-27 kOhm-0.25 W;
• R2 – variable resistor with built-in switch 0.5-1 MOhm-0.5 W;
• VD1 – rectifier diode 1N4148, 1N4002 or similar;
• VS1 – triac BT136-600D or BT136-600E;
• VS2 – dinistor DB3;
• LED – indicator light emitting diode.

The dimmer in the given configuration is designed to connect an electrical appliance with a power of no more than 500 W. If the load power exceeds 150 W, then the triac is mounted on a radiator. The 25 by 30mm PCB is available for download here.

Application area

IN Everyday life A dimmer is most often used to adjust the brightness of lighting lamps. By connecting it to the power supply circuit of halogen lamps, you get a ready-made device for smooth ignition of light, which significantly extends the service life of the lighting device. Often radio amateurs assemble a dimmer with their own hands to regulate the heating of the soldering iron. A power regulator with increased load capacity can be used to change the rotation speed of an electric drill.

It is prohibited to connect the dimmer to electrical appliances that contain the electronic unit signal processing (for example, power supply). The exception is dimmable LED lamps.

Read also

ledjournal.info

How to make a dimmer for 220 and 12 V: diagrams, videos, instructions

Very often there is a need to regulate the brightness of a lamp within a certain value, usually from 20 to 100% brightness. It makes no sense to do less than 20%, since the lamp will not provide a luminous flux, but only a weak glow will occur, which can only be useful for decorative purposes. You can go to the store and buy a finished product, but now the prices for these devices are, to put it mildly, inadequate. Since we are jacks of all trades, we will make these devices ourselves. Today we’ll look at several diagrams that will help you understand how to make a 12 and 220 V dimmer with your own hands.

On a triac

First, let's look at the circuit of a dimmer operating from a 220-volt network. This type The devices operate on the principle of phase shifting of the opening of the power switch. The heart of the dimmer is an RC circuit of a certain value. Control pulse generation unit, symmetrical dinistor. And actually the power switch itself, a triac.

Let's consider the operation of the circuit. Resistors R1 and R2 form a voltage divider. Since R1 is variable, it changes the voltage in the R2C1 circuit. Dinistor DB3 is connected to the point between them and when the voltage reaches its opening threshold on capacitor C1, it is triggered and supplies an impulse to the power switch triac VS1. It opens and allows current to pass through itself, thereby turning on the network. The position of the regulator determines at what point in the phase wave the power switch will open. It can be 30 Volts at the end of the wave, and 230 Volts at the peak. Thereby introducing part of the voltage into the load. The graph below shows the process of regulating lighting with a dimmer on a triac.

In these graphs, the value (t*) is the time during which the capacitor is charged to the opening threshold, and the faster it picks up voltage, the earlier the switch turns on, and the greater the voltage appears on the load. This dimmer circuit is simple and easy to repeat in practice. We recommend watching the video below, which clearly shows how to make a dimmer on a triac:

Triac power regulator 1000 W

On thyristors

If you have a bunch of old TVs and other things gathering dust in the bins of crazy people, you can not buy a triac, but make a simple dimmer using thyristors. The circuit is slightly different from the previous one in that each half-wave has its own thyristor, and thus its own dinistor for each switch.

Let us briefly describe the regulation process. During the positive half-wave, capacitance C1 is charged through the chain R5, R4, R3. When the opening threshold of dinistor V3 is reached, the current through it flows to the control electrode V1. The key opens by passing a positive half-wave through itself. When the phase is negative, the thyristor is locked, and the process is repeated for another key V2, charging through the chain R1, R2, R5.

Phase regulators - dimers can be used not only to adjust the brightness of incandescent lamps, but also to regulate the rotation speed of the hood fan, make an attachment for a soldering iron and thus regulate the temperature of its tip. Also, using a homemade dimmer, you can regulate the speed of a drill or vacuum cleaner and many other uses.

Video assembly instructions:

Thyristor dimmer assembly

Important! This method regulation is not suitable for working with fluorescent, energy-saving compact and LED lamps.

Capacitor dimmer

Along with smooth regulators, capacitor devices have become widespread in everyday life. The operation of this device is based on the dependence of alternating current transmission on the capacitance value. The larger the capacitor's capacitance, the more current it passes through its poles. This type of homemade dimmer can be quite compact, and depends on the required parameters and capacitor capacity.

As can be seen from the diagram, there are three positions of 100% power, through the damping capacitor and off. The device uses non-polar paper capacitors, which can be obtained from old technology. We talked about how to properly desolder radio components from boards in the corresponding article!

Below is a table with the capacitance-voltage parameters on the lamp.

Based on this circuit, you can assemble a simple night light yourself and use a toggle switch or switch to control the brightness of the lamp.

On the chip

To regulate power to the load in 12 Volt DC circuits, they are often used integral stabilizers- Krenki. The use of a microcircuit simplifies the development and installation of devices. This homemade dimmer is easy to set up and has protection functions.

Using variable resistor R2, a reference voltage is created at the control electrode of the microcircuit. Depending on the set parameter, the output value is adjusted from a maximum of 12V to a minimum of tenths of a volt. The disadvantage of these regulators is the need to install an additional radiator for good cooling of the KREN, since part of the energy is released on it in the form of heat.

This lighting controller was repeated by me and did an excellent job with a 12 Volt LED strip, three meters long and the ability to adjust the brightness of the LEDs from zero to maximum. For not very lazy craftsmen, we can suggest making a house dimmer using an integrated timer 555, which controls the KT819G power switch and short PWM pulses.

In this mode, the transistor is in two states: completely open or completely closed. The voltage drop across it is minimal and allows the use of a circuit with a small radiator, which compares favorably with the previous circuit with a ROLL regulator in terms of size and efficiency.

Making a 12 Volt light controller

That's all the ideas for assembling a simple dimmer at home. Now you know how to make a dimmer with your own hands for 220 and 12V.

samelectrik.ru

Fan speed controller connection diagram

Often households need to install a fan speed controller. It should be noted right away that a regular dimmer for adjusting the brightness of lighting is not suitable for a fan. For a modern electric motor, especially an asynchronous one, it is important to have at the input correct form sine wave, but conventional lighting dimmers distort it quite strongly. To effectively and correctly regulate fan speed, you must:

Methods for adjusting the rotation speed of household fans

There are quite a lot in various ways adjusting the fan speed, but only two of them are practically used at home. In any case, you can only reduce the engine speed below the maximum possible according to the device data sheet.

It is possible to accelerate an electric motor only using a frequency regulator, but it is not used in everyday life because it has both a high intrinsic cost and the price of the service for its installation and commissioning. All this makes the use of a frequency regulator not rational at home.

It is allowed to connect several fans to one regulator, unless their total power exceeds the rated current of the regulator. When choosing a regulator, keep in mind that the starting current of the electric motor is several times higher than the operating current.

Ways to adjust fans at home:

Very often the electric motor hums at low speeds when using the first two adjustment methods; try not to operate the fan for a long time in this mode. If you remove the cover, then using the special regulator located under it, you can, by rotating it, set the lower limit of the motor speed.

Connection diagram for a triac or thyristor fan speed controller

Almost all regulators have fusible switches inside, protecting them from overload currents or short circuit, in the event of which it burns out. To restore functionality, it will be necessary to replace or repair the fusible rate.

The regulator is connected quite simply, like a regular switch. The first contact (with the image of an arrow) is connected to the phase from the apartment's electrical wiring. On the second (with an arrow in the opposite direction), if necessary, a direct phase output is connected without adjustment. It is used to turn on, for example, additional lighting when the fan is turned on. The fifth contact (with the image of an inclined arrow and a sine wave) is connected to the phase going to the fan. When using such a scheme, it is necessary to use a distribution box for connection, from which Zero and, if necessary, Ground are connected directly to the fan, bypassing the regulator itself, which requires only 2 wires to connect.

But if the electrical distribution box is located far away, and the regulator itself is located next to the fan, then I recommend using the second scheme. The power supply cable comes to the regulator, and then goes straight from it to the fan. Phase wires are connected in the same way. And 2 zeros are placed on contacts No. 3 and No. 4 in any order.

Connecting the fan speed controller is quite easy to do with your own hands, without calling specialists. Be sure to study and always follow electrical safety rules - work only on a de-energized section of electrical wiring.

jelektro.ru

Speed ​​controller for 12V motor or lamp dimmer - Car DIY

This circuit can be used as a speed controller for a 12V motor up to 5A (DC) or as a dimmer for a 12V halogen or standard incandescent lamp up to 50W. Depending on the load (motor or lamp), the power changes using pulse-width modulation (PWM) with a pulse frequency of about 220Hz.

The Silicon Chip company has been producing various speed controller microcircuits for 12-24V and a current of 20-40A for many years.

However, for most applications it is quite enough to assemble a simpler and cheaper design. That's why we present this basic design that uses a 7555 timer and field-effect transistor.

Being a simple design, it does not monitor the motor's EMF to provide improved speed control and also does not have any sophisticated overload protection other than a fuse. However, it is very effective at a low cost per set of parts.

There are many applications for this circuit where 12V motors, fans or lamps are used. You can use it in cars, boats, and vehicles for recreation, in model boats and railways and so on. Want to control a 12V fan in your car or computer? This circuit will do it for you.

The 7555 timer circuit generates variable width pulses at a frequency of approximately 210 Hz through transistors Q1 and Q2 to FET Q3, which controls the speed of the motor or the brightness of the lamp.

Although the circuit can dim 12V halogen lamps, it should be noted that using halogen lamps in this mode is very wasteful. In situations where lamps with variable brightness are needed, it is much better to use 12V LED lamps, which are now available in a variety of standard sockets, including MR16 for halogens. In addition, they heat up much less and last longer.

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Not every modern drill or grinder is equipped with a factory speed regulator, and most often speed control is not provided at all. However, both angle grinders and drills are built on the basis of commutator motors, which allows each of their owners, even if they know how to handle a soldering iron, to make their own speed controller from available electronic components, either domestic or imported.

In this article we will look at the diagram and principle of operation of the simplest engine speed controller for a power tool, and the only condition is that the engine must be a commutator type - with characteristic lamellas on the rotor and brushes (which sometimes spark).

The above diagram contains a minimum of parts and is suitable for power tools up to 1.8 kW and above, for a drill or grinder. A similar circuit is used to adjust speed in automatic transmissions. washing machines, which contain commutator high-speed motors, as well as in dimmers for incandescent lamps. Such circuits, in principle, will allow you to regulate the heating temperature of a soldering iron tip, an electric heater based on heating elements, etc.

The following electronic components will be required:

Constant resistor R1 - 6.8 kOhm, 5 W.

Variable resistor R2 - 2.2 kOhm, 2 W.

Constant resistor R3 - 51 Ohm, 0.125 W.

Film capacitor C1 - 2 µF 400 V.

Film capacitor C2 - 0.047 uF 400 volts.

Diodes VD1 and VD2 - for voltage up to 400 V, for current up to 1 A.

Thyristor VT1 - for the required current, for a reverse voltage of at least 400 volts.

The circuit is based on a thyristor. A thyristor is a semiconductor element with three terminals: anode, cathode, and control electrode. After a short pulse of positive polarity is applied to the control electrode of the thyristor, the thyristor turns into a diode and begins to conduct current until this current in its circuit is interrupted or changes direction.

After the current stops or when its direction changes, the thyristor will close and stop conducting current until the next short pulse is applied to the control electrode. Well, since the voltage in the household network is alternating sinusoidal, then each period of the network sinusoid the thyristor (as part of this circuit) will work strictly starting from the set moment (in the set phase), and the less the thyristor is open during each period, the lower the speed will be power tool, and the longer the thyristor is open, the higher the speed will be.

As you can see, the principle is simple. But when applied to a power tool with a commutator motor, the circuit works more cleverly, and we will talk about this later.

So, the network here includes in parallel: a measuring control circuit and a power circuit. The measuring circuit consists of constant and variable resistors R1 and R2, capacitor C1, and diode VD1. What is this chain for? This is a voltage divider. The voltage from the divider, and what is important, the back-EMF from the motor rotor, add up in antiphase, and form a pulse to open the thyristor. When the load is constant, then the open time of the thyristor is constant, therefore the speed is stabilized and constant.

As soon as the load on the tool, and therefore on the engine, increases, the value of the back-EMF decreases, since the speed decreases, which means the signal to the control electrode of the thyristor increases, and opening occurs with less delay, that is, the power supplied to the engine increases, increasing the dropped speed . This way the speed remains constant even under load.

As a result of the combined action of signals from the back-EMF and from the resistive divider, the load does not greatly affect the speed, but without a regulator this influence would be significant. Thus, using this circuit, stable speed control is achievable in each positive half-cycle of the network sinusoid. At medium and low rotation speeds this effect is more pronounced.

However, with increasing speed, that is, with increasing voltage removed from the variable resistor R2, the stability of maintaining a constant speed decreases.

In this case, it is better to provide a shunt button SA1 parallel to the thyristor. The function of diodes VD1 and VD2 is to ensure half-wave operation of the regulator, since the voltages from the divider and the rotor are compared only in the absence of current through the motor.

Capacitor C1 expands the control zone at low speeds, and capacitor C2 reduces sensitivity to interference from brush sparking. The thyristor needs to be highly sensitive so that a current of less than 100 μA can open it.

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 high-quality scheme, 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 indicators 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 starting the engine at maximum speed, the a large number of heat, 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

Make homemade regulator revving 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 with best side. 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 adjustment, variable resistors are included in the circuit, which change the amplitude incoming signal, providing a smooth or stepwise change in speed.

PWM transistor circuit

You can regulate the shaft rotation speed of low-power electric motors using a transistor bus and serial connection 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 Various types 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.