Speed Regulator For Grinders Without Power Loss

Description of the electric motor speed controller without power loss

Each of us at home has some kind of electrical appliance that has been working in the house for more than one year. But over time, the power of technology weakens and does not fulfill its direct purposes. It is then that you should pay attention to the insides of the equipment. Basically, problems arise with the electric motor, which is responsible for the functionality of the equipment. Then you should pay attention to a device that regulates the engine power speed without reducing their power.

Power speed regulator

Engines are different in characteristics. This means that this or that technique works at different frequencies of revolution of the shaft that starts the mechanism. Motor can be:

Single-phase,
Biphasic,
Three-phase.

Mostly three-phase electric motors are found in factories or large factories. At home, single-phase and two-phase are used. This electricity is enough to operate household appliances.

Work principles

The 220 V motor speed controller without power loss is used to maintain the initial set shaft speed. This is one of the basic principles of this device, which is called a frequency regulator.

With it, the electrical appliance works at the set engine speed and does not reduce it. Also, the motor speed controller affects the cooling and ventilation of the motor. With the help of power, the speed is set, which can be either increased or decreased.

The question of how to reduce the speed of a 220 V electric motor was asked by many people. But this procedure is pretty simple. One has only to change the frequency of the supply voltage, which will significantly reduce the performance of the motor shaft. You can also change the power supply to the motor by using its coils. Electricity control is closely related to magnetic field and motor slip. For such actions, they mainly use an autotransformer, household regulators, which reduce the speed of this mechanism. But it is also worth remembering that the engine power will decrease.

Shaft rotation

Engines are divided into:

Asynchronous,
Collector.

The speed controller of an induction motor depends on the connection of current to the mechanism. The essence of the operation of an asynchronous motor depends on the magnetic coils through which the frame passes. She pivots on sliding contacts. And when, when turning, it turns 180 degrees, then, according to these contacts, the connection will flow in the opposite direction. Thus, the rotation will remain unchanged. But with this action, the desired effect will not be obtained. It will come into force after a couple of dozen frames of this type are introduced into the mechanism.

The brushed motor is used very often. Its operation is simple, since the transmitted current passes directly, because of this, the power of the revolutions of the electric motor is not lost, and the mechanism consumes less electricity.

Speed Regulator For Grinders Without Power Loss

The washing machine motor also needs power adjustment. For this, special boards were made that do their job: the engine speed control board from the washing machine is multifunctional, since when it is used, the voltage decreases, but the rotation power is not lost.

The circuit of this board has been verified. One has only to put bridges from diodes, choosing an optocoupler for the LED. In this case, you still need to put the triac on the radiator. Basically, engine tuning starts at 1000 rpm.

If you are not satisfied with the power regulator and lack its functionality, you can make or improve the mechanism. To do this, you need to take into account the current strength, which should not exceed 70 A, and heat transfer during use. Therefore, you can install an ammeter to adjust the circuit. The frequency will be small and will be determined by the capacitor C2.

The next step is to adjust the regulator and its frequency. When exiting, this pulse will go out through a push-pull transistor amplifier. You can also make 2 resistors that will serve as an output for the computer’s cooling system. To prevent the circuit from burning out, a special lock is required, which will serve as double the current value. So this mechanism will work for a long time and in the right amount. Power control devices will provide your electrical appliances with many years of service at no extra cost.

Design features

The microcircuit is equipped with everything necessary to implement high-quality motor control in various speed modes, from braking to acceleration and rotation at maximum speed. Therefore, its use greatly simplifies the design, while simultaneously doing the entire drive universal, since you can select any revolutions with a constant torque on the shaft and use it not only as a drive for a conveyor belt or a drilling machine, but also to move 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 design the converter. These include: an integrated circuit for converting frequency into voltage, an acceleration generator, a soft starter, a Tahoe signal processing unit, a current limiting module, etc. As you can see, the circuit is equipped with a number of protections that will ensure the stability of the regulator in different modes.

The figure below shows a typical circuit for switching on a microcircuit.

The scheme is simple, therefore it is quite reproducible with your own hands. There are some features, which include the limit values and the way the speed is controlled:

The maximum current in the motor windings should not exceed 10 A (subject to the configuration shown in the diagram). If you use a triac with a large forward current, then the power can be higher. Please note that you will need to change the resistance in the feedback loop down, as well as the inductance of the shunt.
The maximum rotation speed is reached 3200 rpm. This characteristic depends on the type of engine. The circuit can control motors up to 16 thousand rpm.
Acceleration time to maximum speed reaches 1 second.
Normal acceleration is provided in 10 seconds from 800 to 1300 rpm.
The motor uses an 8-pole tachogenerator with a maximum output voltage of 6000 rpm 30 V. That is, it should give 8 mV at 1 rpm. At 15,000 rpm, it should have a voltage of 12 V.
To control the motor, a 15A triac and 600 V limit voltage is used.

If it is necessary to organize the reverse of the motor, then for this it will be necessary to supplement the circuit with a starter that will switch the direction of the excitation winding. A zero speed control circuit will also be required to enable reverse. Not indicated in the figure.

Lossless collector motor speed controller

Many types of work on wood, metal or other types of materials do not require high speeds, but good traction. It would be more correct to say. Moment. It is thanks to him that the planned work can be performed efficiently and with minimal power losses. For this, DC motors (or collector motors) are used as a driving device, in which the supply voltage is rectified by the unit itself. Then, in order to achieve the required performance, it is necessary to adjust the speed of the collector motor without losing power.

Features of speed regulation
Generalized regulator circuit
Varieties of collector motors
Motor design
Scheme selection
Design features
Control principle

Motor design

Structurally, the motor from the Indesit washing machine is simple, but when designing a regulator for controlling its speed, it is necessary to take into account the parameters. Motors can be different in characteristics, due to which the control will also change. The mode of operation is also taken into account, on which the design of the converter will depend. Structurally, the commutator motor consists of from the following components:

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

With an increase in the current in the motor circuit, connected according to the standard scheme, the field winding is connected in series with the armature. With this inclusion, we also increase the magnetic field acting on the armature, which makes it possible to achieve linear characteristics. If the field remains unchanged, then it is more difficult to obtain good dynamics, not to mention large losses in power. Such motors are best used at low speeds, since they are more convenient to control at small discrete movements.

By organizing separate control of the excitation and the 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 regulator that 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 is made from the engine from the washing machine.

Varieties of collector motors

At least two types of collector motors are known. The first includes devices with an armature and a field winding on the stator. The second includes devices with an anchor and permanent magnets. You also need to decide, for what purposes it is required to design a regulator:

If it is necessary to adjust with a simple movement (for example, by rotating a grinding stone or drilling), then the speed will need to be changed in the range from some minimum value, which is not equal to zero, to a maximum. Approximate figure: from 1000 to 3000 rpm. For this, a simplified circuit with 1 thyristor or a pair of transistors is suitable.
If it is necessary to control the speed from 0 to maximum, then you will have to use full-fledged converter circuits with feedback and rigid control characteristics. Usually, self-taught masters or amateurs have precisely collector motors with an excitation winding and a tachogenerator. Such a motor is a unit used in any modern washing machine and often fails. Therefore, we will consider the principle of controlling this particular engine, having studied its device in more detail.

Features of speed regulation

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

You can design with your own hands only some semblance of a regulator, but it’s not worth talking about preserving power. What is power? In terms of electrical performance, this is the product of the current consumption times the voltage. The result will give a certain value that includes active and reactive components. To select only the active one, that is, to reduce the losses to zero, it is necessary to change the nature of the load to the active one. Only semiconductor resistors have such 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 conserve torque, not power: it will change anyway. 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.

Scheme selection

Having found out all the conditions under which the motor will be used, you can begin to manufacture the speed controller of the collector 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.

Considering the many schemes on the Internet, we can conclude that few people are engaged in the creation of 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. Consider one of the schemes that is popular with self-taught craftsmen or those who just want to usefully use an old engine from a washing machine.

All our criteria are met by the control circuit of the rotational speed of the collector motor, assembled on the specialized microcircuit TDA 1085. This is a completely ready-made driver for controlling the motors that allow you to adjust the speed from 0 to the maximum value, ensuring the maintenance of the torque by using a tachogenerator.

Electric motor speed controller without power loss

The board for adjusting the revolutions of collector electric motors on the TDA1085 microcircuit allows you to control the motors without losing power. A prerequisite is the presence of a tachometer (tachogenerator) on the electric motor, which allows the motor to provide feedback with the control board, namely the microcircuit. In simpler terms, so that everyone would understand, something like the following happens. The motor rotates with a certain number of revolutions, and the tachometer installed on the electric motor shaft records these readings. If you start to load the engine, the shaft speed will naturally begin to drop, which will also be fixed by the tachometer. Now let’s look further. The signal from this tachometer goes to the microcircuit, it sees this and gives a command to the power elements to add voltage to the electric motor. Thus, when you pressed on the shaft (giving a load), the board automatically added voltage and the power on this shaft increased. Conversely, let go of the motor shaft (remove the load from it), she saw this and reduced the voltage. Thus, the revolutions remain not low, but the moment of force (torque) is constant. And most importantly, you can adjust the rotor speed in a wide range, which is very convenient in the use and design of various devices. Therefore, this product is called “Board for adjusting the speed of collector motors without power loss”.

But we saw one peculiarity that this board is applicable only for collector motors (with electric brushes). Of course, such motors are much less common in everyday life than asynchronous ones. But they are widely used in automatic washing machines. This is why this circuit was made. Especially for the electric motor from the washing machine automatic machine. Their power is quite decent, from 200 to 800 watts. That allows them to be widely used in everyday life.

This product has already found wide application in the household of people and has widely covered people engaged in various hobbies and professional activities.

Answering the question. Where can you apply a washing machine motor? Some list was formed. Homemade wood lathe; Grinder; Electric drive for concrete mixer; Sharpener; Electric drive for honey extractor; Straw cutter; Homemade pottery wheel; Electric lawn mower; Wood splitter and many other things where mechanical rotation of any mechanisms or objects is necessary. And in all these cases, we are helped by this board “Adjusting the speed of electric motors with maintaining power on the TDA1085”.

Crash test of the speed control board

The board for adjusting the revolutions of collector electric motors on the TDA1085 microcircuit allows you to control the motors without losing power. A prerequisite is the presence of a tachometer (tachogenerator) on the electric motor, which allows the motor to provide feedback to the control board, namely the microcircuit. In simpler terms, so that everyone would understand, something like the following happens. The motor rotates with a certain number of revolutions, and the tachometer installed on the shaft of the electric motor records these readings. If you start to load the engine, the shaft speed will naturally begin to drop, which will also be fixed by the tachometer. Now let’s look further. The signal from this tachometer goes to the microcircuit, it sees this and gives a command to the power elements to add voltage to the electric motor. Thus, when you pressed on the shaft (giving a load), the board automatically added voltage and the power on this shaft increased. Conversely, let go of the motor shaft (remove the load from it), she saw this and reduced the voltage. Thus, the revolutions remain not low, but the moment of force (torque) is constant. And most importantly, you can adjust the rotor speed in a wide range, which is very convenient in the use and design of various devices. Therefore, this product is called “Board for adjusting the speed of collector motors without power loss”.

This product has already found wide application in the household of people and has widely covered people engaged in various hobbies and professional activities.

Crash test of the speed control board

The board for adjusting the revolutions of collector electric motors on the TDA1085 microcircuit allows you to control the motors without losing power. A prerequisite is the presence of a tachometer (tachogenerator) on the electric motor, which allows the motor to provide feedback to the control board, namely the microcircuit. In simpler terms, so that everyone would understand, something like the following happens. The motor rotates with a certain number of revolutions, and the tachometer installed on the electric motor shaft records these readings. If you start to load the engine, the shaft speed will naturally begin to drop, which will also be fixed by the tachometer. Now let’s look further. The signal from this tachometer goes to the microcircuit, it sees this and gives a command to the power elements to add voltage to the electric motor. Thus, when you pressed on the shaft (giving a load), the board automatically added voltage and the power on this shaft increased. Conversely, let go of the motor shaft (remove the load from it), she saw this and reduced the voltage. Thus, the revolutions remain not low, but the moment of force (torque) is constant. And most importantly, you can adjust the rotor speed in a wide range, which is very convenient in the use and design of various devices. Therefore, this product is called “Board for adjusting the speed of collector motors without power loss”.

This product has already found wide application in the household of people and has widely covered people engaged in various hobbies and professional activities.

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