Smooth start for circular how to make. Integral regulator

12th January 2023

How to install a smooth start on a circular

Devices with simistors at 20 A are suitable for professional Bulgarians. Many models use contact resistor resistors. First of all, they are able to work at a high frequency. The maximum temperature of the starters is 55 degrees. Most models are well protected by the case. The standard device scheme involves the use of three contrasts with a capacity of 30 pf. Experts say that the devices are distinguished by their conductivity.

The minimum frequency of starters is 35 Hz. They are capable of working on a direct current network. Connection of modifications is carried out through adapters. For 200 W engines, such devices are well suited. Filters are often installed with triodes. The sensitivity indicator in them is no more than 300 mV. Quite often there are wired comparators with a protection system. If we consider imported models, then they have an integral converter that is installed with insulators. Current conductivity is provided at the mark of 5 MK. With a resistance of 40 Ohms, the model is able to steadily maintain large speeds.

Homemade options

There are many schemes for the modernization of power tools using SCP. Among all varieties, devices on Simistors are widely used. Simistor is a semiconductor element that allows you to smoothly adjust the power parameters. There are simple and complex schemes that differ among themselves options for execution, as well as the supported power, connected power tools. The constructive design is internal, allowing you to integrate inside the body, and external, made in the form of a separate module, which acts as a speed limiter and starting current during direct starting angular grind.

The simplest scheme

UPP with the regulation of revolutions on the thyristor KU 202 has been widely used due to a very simple execution scheme (Scheme 1). Its connection does not require special skills. Radio elements for him to get it very simple. This model of the regulator is made of a diode bridge, a variable resistor (acts as a regulator U) and the tiristor setup circuit (feed U to a 6.3.volt number control exit) of a domestic manufacturer.

The basic principle of operation is to adjust the revolutions of the instrument electric motor due to restriction of power in manual mode. This circuit allows the use of power tools with a capacity of up to 1.5 kW. To increase this indicator, it is necessary to replace the thyristor with a more powerful one (information about this can be found on the Internet or a directory). In addition, it is necessary to take into account the fact that the thyristor control scheme will differ from the original. KU 202 is an excellent thyristor, but its significant drawback is to set it up (a selection of parts for the control scheme). To make a smooth start in automatic mode, scheme 2 (SCP on the microcircuit) is used).

Smooth launch on the microcircuit

The best option for the manufacture of SCP is the SCP scheme on one simistor and microcircuit, which controls the smooth opening of the transition P-N type. The device from the 220 V network is powered and it is easy to assemble it yourself. A very simple and universal scheme of smooth starting the electric motor also allows you to adjust the speed (Scheme 2). Simistor can be replaced with similar or with characteristics exceeding the initial ones, according to the reference book of the semiconductor.type radio elements.

Scheme 2. Scheme of smooth launch of power tools

The device is implemented on the basis of the KR118PM1 chip and the Simistor. Thanks to the universality of the device, it can be used for any tool. It does not require tuning and is installed in the rupture of the power cable.

When starting the electric motor, the UD on KR118PM1 and the smooth growth of the capacitor C2 occur. The thyristor opens gradually with a delay depending on the capacity of the control capacitor C2. With a capacity of C2 = 47 μF, a delay occurs when it is launched about 2 seconds. It depends directly in proportion to the capacitor capacity (with a larger capacity, the launch time increases). When disconnected, the angular grinder capacitor C2 is discharged using the resistor R2, the resistance of which is 68 K, and the discharge time is about 4 seconds.

To regulate revolutions, you need to replace R1 with a variable resistor. When the parameter of the variable resistor changes, the power of the electric motor occurs. R2 changes the value of the current flowing through the input of the systemist. The simistor needs cooling and, therefore, a fan can be built into the module case.

Thus, to launch electric motors of various tools, it is necessary to use the UPP of the factory manufacturing or homemade. SCP are used to increase the life of the tool. When the engine is launched, there is a sharp increase in the consumption current by 7 times. Because of this, it is possible to burn stator windings and wear of the mechanical part. SCP allow significantly reducing the starting current. In the manufacture of SCP, you need to comply with the safety rules when working with electricity.

The smooth starting device is an electrical device used in asynchronous electric motors, which allows you to hold the parameters of the engine (current, voltage, etc.D.) in safe limits. Its use reduces the starting currents, reduces the likelihood of overheating of the engine, eliminates jerks in mechanical drives, which, ultimately, increases the service life of the electric motor.

Making a smooth start

The scheme is assembled on a printed circuit board with dimensions of 45 x 35 mm, the board is divorced as compact as possible so that it can be built into the body of the tool, which requires smooth start. It is better to solder the power wires directly into the board, but if the load power is small, then you can install terminals, as I did. The board is made by the Lut method, the process photos are presented below.

It is advisable to tie the paths before the sinking of parts, so their conductivity improve. The microcircuit can be installed in the panel, then it can be removed without problems from the board. First, resistors, diodes, small capacitors are sealed, and later the largest components. After completing the assembly of the board, it must be checked for the correct installation, call the paths, wash the remaining flux.

The simplest scheme

Due to the size and number of parts, the regulator of this type can be built into the power tool case. In addition, the handle of a variable resistor should be removed and the revolution regulator itself can be finalized by integrating the button in front of the diode bridge. The basic principle of operation is to adjust the revolutions of the instrument electric motor due to restriction of power in manual mode. This circuit allows the use of power tools with a capacity of up to 1.5 kW. To increase this indicator, it is necessary to replace the thyristor with a more powerful one (information about this can be found on the Internet or a directory). In addition, it is necessary to take into account the fact that the thyristor control scheme will differ from the original. KU 202 is an excellent thyristor, but its significant drawback is to set it up (a selection of parts for the control scheme). To make a smooth start in automatic mode, scheme 2 (SCP on the microcircuit) is used).

Why did you need a smooth engine start

So, the problem is that the boiler room has water recharge pumps with water. Only two pumps, and they are turned on by command from a system of tracking water level in the boiler. Only one pump can work at the same time, the choice of the pump is carried out by the operator of the boiler room by switching water cranes and electric switches.

Pumps are driven by conventional asynchronous engines. Asynchronous engines of 7.5 kW are turned on through conventional contactors (magnetic starters). And since the power is large, the start is very tough. Each time the startup occurs, a tangible hydraulic system occurs. The engines, and pumps, and hydraulic system spoil. Sometimes it feels like pipes and cranes will now shatter.

In addition, when the boiler is cooled, and hot water (more than 95 ° C) is sharply supplied to it, then unpleasant phenomena take place that resemble explosive seething. It happens vice versa, water with a temperature of 100 ° C can be cold. when there is dry steam with a temperature of almost 200 ° C in the boiler. In this case, harmful hydraulic boards also occur.

There are two identical boilers on the boiler room, but the second frequency traitors are installed on the pumps. Boilers (more precisely, steam generators) produce steam with a temperature of more than 115 ° C and pressure up to 14 kgf/cm2.

It is a pity that the design of the boiler in the electric circuit did not provide for the smooth inclusion of the pump engines. Although the boilers are Italian, it was decided to save on this.

I repeat that for smooth inclusion of asynchronous engines, we have the choice of the following options:

In this case, it was necessary to choose the option in which there would be a minimum intervention in the operating circuit of the boiler.

7.04 Модификатор TurboSmooth Сглаживание

The fact is that any changes in the work of the boiler must be agreed with the manufacturer of the boiler (or a certified organization) and with the supervisory organization. Therefore, the changes should be made imperceptibly and without unnecessary noise. Although, I do not interfere in the security system, so it’s not so strict here.

My regular readers know that now, after passing the exams, I have every right to carry out capes in the boiler room.

Use in corner grinding

During the launch of the angular grinding machine (angular grinder), high dynamic loads appear on the details of the tool.

Dear models are equipped with UPP, but not ordinary varieties, for example, an angular grinder of Interskol. An inertial jerk is able to tear out a corner grinder from the hands, while a threat occurs to life and health. In addition, when starting the instrument electric motor, the current is overloaded and, as a result of this, the wear of the brushes and significant heating of the stator windings, the gearbox wear out and the destruction of the cutting disk, which can crack at any time and cause harm to health, and maybe even life. The tool needs to be secured and for this you should make an angular grinding grinder with a speed of revolutions and smooth starting with your own hands.

Homemade options

The simplest scheme

Scheme 1. The electrical circuit of the internal unit with speed adjustment and a smooth start (electrical circuit circuit)

The basic principle of operation is to adjust the revolutions of the instrument electric motor due to restriction of power in manual mode. This circuit allows the use of power tools with a capacity of up to 1.5 kW. To increase this indicator, it is necessary to replace the thyristor with a more powerful one (information about this can be found on the Internet or a directory). In addition, it is necessary to take into account the fact that the thyristor control scheme will differ from the original. KU 202 is an excellent thyristor, but its significant drawback is to set it up (a selection of parts for the control scheme). To make a smooth start in automatic mode, scheme 2 (SCP on the microcircuit) is used).

Smooth launch on the microcircuit

The best option for the manufacture of SCP is the SCP scheme on one simistor and microcircuit, which controls the smooth opening of the transition P-N type. The device from the 220 V network is powered and it is easy to assemble it yourself. A very simple and universal scheme of smooth starting the electric motor also allows you to adjust the speed (Scheme 2). Simistor can be replaced with similar or with characteristics exceeding the initial ones, according to the reference book of the semiconductor.type radio elements.

Vector Line Integral over Circular Path Traced Clockwise

Scheme 2. Scheme of smooth launch of power tools

The main function of capacitors C1 and C3 is the protection and management of the microcircuit. The Simistor should be selected, guided by the following characteristics: Direct U should be 400.500 V and direct current should be at least 25 A. With such values of radio elements, it is possible to connect a tool with a capacity of 2 kW to 5 kW to the UPP.

When the electric engine is launched, there is a starting moment that seals the voltage due to the occurrence of starting currents. They are 9 times higher than working currents. This does not affect the stable operation of electrical appliances, reduces the life of the engine. All because the engine starts begins to drag out and its windings are overheated. Experts advise adding devices to the engine that can start it with smooth. Homemade also learned to make devices for smooth starting an electric engine with their own hands.

Bulgarian devices for 800 watts

800 watts corner grinder work with low frequency starters. Simistors are often used on 15 A. If we talk about the models scheme, it is worth noting that they use expansion transistors, in which the current capacity starts from 45 μ. Capacitors are used with and without filters, and the container of elements is no more than 3 pf. It is also worth noting that starters differ in sensitivity.

If we consider professional corner grinders, then 400 mV modifications are suitable for them. In this case, the conductivity of the current can be low. There are also devices with variable transistors. They quickly warm up, but are not able to maintain large revolutions of corner grinding, and their conductivity is about 4 μ. If we talk about other parameters, then the rated voltage starts from 230 V. The minimum frequency of models with broadband systems is 55 Hz.

Features and service life

In manual power tools, such as: angular grinder (angular grinder), circular saw, electric screwdriver, drill. collector engines with sequential excitement are used. They can work on constant and on alternating current.

In most cases, a regular power grid 230 in 50 Hz is used to write them down in most cases. Previously, a network of 380 in a professional tool was used. Now, with the growth of consumer power in single.phase networks (offices and residential sector), professional power tools for 220 in.

Collector engines have a large torque and starting moments, compact, are easily made for increased voltage. The torque here is a decisive. With a low mass of the machine, it is just suitable for manual power tools. But such electric motors have disadvantages and weaknesses. One of these weaknesses is the brush knot.

Brushes from pressed graphite with fillers rub on the copper plates of the collector and are subjected to mechanical wear and electricity. This leads to an increase in sparking and increases the fire and explosion hazard of the power tool. Mineral dust getting inward accelerates wear. Although the fans provided for by the design blow air out, dust and cement can easily get inside. During downtime, if the tool was unsuccessfully laid, dust easily gets inside. In practice, this is a constant phenomenon.

Brushes of an electric motor from pressed graphite

Another drawback of the power tool is frequent breakdowns of the gearbox. This happens just due to a large starting moment. The advantage turns into a disadvantage. With a breakdown of the gearbox, you have to change the tool, they usually are not subject to repair. Unfortunately, industry, in an effort to reduce the cost of products, does this due to the quality. If you want to use a good power tool. pay a lot of money.

Connection “Star” and its advantages

The reversing diagram of the engine 380 by 220 volts

Each of the three working windows of the electric motor has two conclusions. respectively, the beginning and end. The ends of all three windings are connected to one common point, the so.called neutral.

In the presence of a neutral wire in the circuit, the circuit is called 4 wired, otherwise, it will be considered 3 wired.

The onset of conclusions is attached to the corresponding phases of the supply network. The applied voltage on such phases is 380 V, less often than 660 V.

The main advantages of applying the star “Star”:

Stable and long.term non.stop operating mode of the engine;
Increased reliability and durability, by reducing the power of equipment;
Maximum smoothness of the electric drive;
The possibility of exposure to short.term overload;
During operation, the equipment housing does not overheat.

There is equipment with an internal connection of the ends of the windings. Only three conclusions will be displayed to the block of such equipment, which does not allow other connection methods to apply. Electrical equipment performed in this form, for its connection does not require competent specialists.

Connection of a three.phase engine to a single.phase network according to the star scheme

AZPT and smooth starting of the collector electric motor

Hello everyone, I would like to share a device that helps me a lot in work. The fact is that I often have to repair washing machines and very often have to check the engines of these machines, as well as other electronic devices. It happens that there are often devices with a short circuit (short circuit), such a device greatly facilitates further repair.

What consists of

A decision was made to assemble the device in a not large distribution box. It was placed in it by a single.pole machine gun at 10a, it is also the first toleep torsion. The phase from the machine to the outlet goes through the cartridge of the incandescent lamp, which is the 2nd degree of protection against KZ. There is also an indication of the inclusion of the machine itself. Indication is made of a 3-volt LED.

The power control board was placed in the same box, it will be our electric motor speed regulator. The phase from the machine enters the gap to the power button, then on the input of the phase in the board of the regulator itself. Zero comes directly to the same fee. The inclusion indication is made of a 3-volt LED. The phase output is filed for the general contact of the 2 positional toggle switch, he also goes to the engine stator. Tumbker will serve as a reverse. The togglerer is connected to the cross, the left and right outputs of the toothbler go to the engine rotor. Zero output from the fee goes to the engine stator.

The simplest regulator scheme

The electrical circuit of the revolutions for the angular grinder is collected on the printed circuit board or mounting installation. over, the printed circuit board can also be made independently with the help of textolite and chlorine iron for the grass. Instead of iron, you can use a mixture of hydrogen peroxide, salt and citric acid.

Engine speed regulator for angular grinder

Configuration of an electrical circuit

resistor R1 (4.7 kOhm);
symmetrical thyristor Diac (DB3);
Symmetric thyristor Triac (VT-136/138);
Tunuetable resistor VR1 (500KU);
capacitor C1 (0.1 μF400V).

Principle of operation

The principle of operation of the scheme is built as follows. VR1 is responsible for the countdown of charging time C1. When the voltage is supplied to the circuit, the thyristors are closed, at the output. 0. As the capacitor is charged, the voltage in it increases and opens Diac, which gives voltage supply to Triac. It also opens and passes the current. Then both thyristors are closed and are in this position until the full reload of C1. As a result, a complex wave signal with an amplitude is formed at the output, which directly depends on the working time of the C1-VR1-R1 chain.

Final assembly and testing of the regulator

A scheme is collected on a printed circuit board or radiator from copper (aluminum)

With a hinged assembly, the place of installation of thyristors (strictly on the radiator, it plays the role of the heat voltage) is especially important). Then a mandatory check of the performance of the circuit is carried out using a conventional electric light bulb

The smoothness of the intensity changes will be the same as in the finished control regulator for angular grinding grinding after the final assembly.

In factory models, a plastic adjusting wheel is provided, if desired, it can also be bought separately and included in the set of a home.made regulator. If the testing has been successful, the regulator is attached to the corner grinder and crashes into a tool for power supply.

How to make a smooth starting circuit for a corner grinding machine with your own hands

The popular scheme is implemented on the basis of the control circuit of the phase regulation KR118PM1, and the power part is made on the simystory. Such a device is simply mounted, does not require additional settings after assembly, and therefore, a master can make it without a specialized education, just be able to hold a soldering iron in your hands.

Electric regimen of smooth starting for angular grinding

The proposed block can be connected to any power tool designed for an alternating voltage of 220 volts. A separate removal of the power button is not required, the modified power tool is turned on the standard key. The circuit can be installed as inside the corner of the corner grinder, and in the gap of the power cable in a separate case.

The most practical is the connection of the unit unit to the outlet, from which the power tool is powered. The input (connector XP1) is supplied from the network 220 volts. A consumable socket is connected to the output (connector XS1), into which the corner grinder plug is sticking.

When the key of the corner grinder is closed, the voltage is supplied to the DA1 chip on the total power circuit. A smooth voltage increase occurs on the control capacitor. As it is charged, it reaches the working value. Due to this, thyristors in the microcircuit do not open immediately, but with a delay, the time of which is determined by the capacitor charge. Simistor VS1, controlled by thyristors, opens with the same pause.

Watch the video with a detailed explanation of how to make and which scheme to apply

In each semi.period of alternating voltage, the delay decreases in arithmetic progression, as a result of which the voltage at the entrance to the power tools smoothly increases. This effect determines the smooth start of the angular grinder engine. Therefore, the speed of the disk increases gradually, and the gear shaft does not experience inertial shock.

The time set to the working value is determined by the capacitance of the capacitor C2. Value 47 μF provides smooth start in 2 seconds. With such a delay, there is no particular discomfort to start working with the tool, and at the same time, the power tool itself is not subjected to excessive loads from a sharp start.

After turning off, the angular grinder, the capacitor C2 is discharged by the resistance of the resistor R1. With a rating of 68 kOhm, the discharge time is 3 seconds. After that, the device of smooth start is ready for the new cycle of the launch of the corner grinder. With a short refinement, the circuit can be modernized to the engine speed controller. For this, the resistor R1 is replaced by the alternating. Adjusting the resistance, we control the engine power, changing its speed.

Thus, in one case, you can perform the engine speed controller and the device of smooth starting power tools.

The remaining details of the scheme are as follows:

The resistor R2 controls the value of the current flowing through the control entrance of the Simistor VS1;
Capacitors C1 and C2 are components of the control of the KR118PM1 microcircuit used in the standard inclusion scheme.

For simplicity and compact installation, resistors and capacitors are soldered directly to the legs of the chip.

Simistor VS1 can be any, with the following characteristics: maximum voltage up to 400 volts, minimum power current 25 amperes. The value of the current depends on the power of the angular grinding machine.

Due to the smooth start of the corner grinder, the current will not exceed the nominal working value for the selected power tool. For emergency cases, for example, jamming of the disk angular grindow. a current supply is needed. Therefore, the value of the nominal value in amperes should be doubled.

The nominal rates of radio components used in the proposed electric circuit are tested for an angular grinder with a capacity of 2 kW. The power supply is up to 5 kW, this is due to the feature of the work of the KR118PM1 chip. Working scheme, repeatedly executed by domestic masters.

If your arsenal has an old corner grinding machine, do not rush to write it off. Using a simple electrical circuit, the device can be easily modernized by adding a function of changing speed changes to it. Thanks to a simple regulator, which is really assembled with your own hands in a few hours, the functionality of the device will increase significantly. Having reduced the speed of rotation, an angular grinder can be used as a grinding and hiding machine for various types of materials. New opportunities appear for the use of additional nozzles and equipment.

Why do you need lightweight starting to the power tool

The smooth start scheme is a small assembly of a total of 5-6 electronic components based on a powerful semiconductor with control from the chip. The dimensions of such a board allow you to place it directly in the handle of the power tool, but modernization is not always promising due to the need to maintain a guarantee from the manufacturer, as well as the possibility of using such a device for various tools. The launch scheme can be made yourself according to several options for drawings from the Internet, but the easiest way for ending or drill are already used ready.made blocks offered in sale. They have many modifications, which requires an understanding of the principle of soft starting and the benefits received.

Slowed launch is primarily necessary to end peeling, which are not equipped with an engine speed adjustment unit. It is advisable to make a smooth launch of the tool with your own hands for a number of reasons:

The launch of a powerful electric motor leads to significant jumps in the mains (peak throws), which negatively affects as a tool, that and the wiring. Alternative sources of electricity, as generators and inverters, are overloaded in such a situation and either turn off in automatic mode, or may fail. Starting through a special module significantly reduces the peak of a voltage throw, which excludes the probability of overload in the entire circuit.
The ending without smooth starting quickly fails due to accelerated grinding of brushes, as well as the occurrence of an electric arc between the contacts, which creates the burnout of the anchor lamella and causes a short circuit of windings of the rotor and stator. The engine dramatically gains momentum, which with significant diameters of the saw leads to large inertial forces that affect the displacement of the tool not only in the hands, but even on stationary fasteners. Such a sharp launch can lead at least to cutting the material in an unplanned place, at a maximum. pulling out the ending from the hands or fastening with the probability of an accident. Installing a small block eliminates such problems.
The slowed down the rotor acceleration at the end saw provides not only its safe operation, but significantly extends the service life, since at the time of the launch, shock loads disappear in the mechanical part of the tool. The gears do not fight among themselves in the programs, and the torque is correctly distributed without destructive consequences, which significantly reduces the mechanical production of the node.

With your own hands

To make the smooth launch of the ending, you can use one of the popular methods:

Collect the electronic circuit yourself according to the drawings proposed on the Internet. This method is more suitable for lovers of electrical work, as knowledge and skills are needed to select components and debug electronic assemblies. Details are purchased strictly according to the required parameters (nominal nominal), and their dimensions are important to minimize the mounted fee. Do not forget that the block will operate under high voltage, so the quality of the soldering and the overall installation must meet the rules of electrical safety. For this reason, the method is not suitable for the average home master.
Purchase a specialized unit unit (BPP) and connect it to the power tool. To ensure soft start for various household devices with electric motors, it is recommended to place the purchased block in an extension cord or carry. But, it is worth considering that there are several options for factory modules for slow acceleration, and they are not interchangeable.

The described method is suitable only for collector engines, it does not work with asynchronous, they have a different principle of excitation of the winding and a completely different device is required to adjust the starting. BPP is designed to connect only one consumer, simultaneously connecting several devices is unacceptable.

Do.it.yourself revolutions

You can make a revolutionary control controller using the output boards of the vacuum cleaner or sewing machine, although the details of the device are inexpensive. The gearbox supports a certain number of revolutions and speed. If the speeds are very large, the matter is most likely in the stature, this device requires repair. You can fix this device at home.

The functioning of the collector engine is provided by any electric voltage; When the power changes, the number of revolutions decreases or increases. This number of times with a thyristor revolutions changes.

Regulator assembly algorithm:

A handle is unscrewed, it is invented where to place the elements of the circuit (if there is not enough space, the device is made in a separate box).
The resistor can be made of aluminum.
With a slight heating of the simistor, a small radiator is enough.
Saving.
Parsing with epoxy resin.

This home.made device is able to last years. Sometimes it accelerates after turning on at increased speeds, which indicates the closure of the stator winding. Most often, the stature needs rewind.

Smooth launch of an asynchronous electric motor

A logical way to reduce the starting current was a decrease in the voltage supplied to the stator at the time of launch, with its gradual increase in engine acceleration.

The simplest and oldest method of smooth start is a rheisted launch of the electric motor: several powerful resistors, sequentially shackled by contactors, are consistently included in the stator chain.

High inductance (reactors), as well as autotransformers, can also be used.

A similar method of smooth start has obvious disadvantages:

The work of the contactors is not tied to the actual current value, they either switch manually or move automatically using the time relay.

Since the torque of the asynchronous engine is proportional to the square of the supply voltage, a reduction in the voltage at the time of starting 2 times will lead to a decrease in the torque by 4 times. The use of smooth starting with electric motors directly connected to the load significantly increases the time of exiting working speeds.

Improving power electronics made it possible to create compact automatic devices of a smooth start (also called SoftTtarters from English Soft Start. “Soft Start”) for asynchronous electric motors installed on a standard installation rail of electrical panels.

They provide not only smooth acceleration, but also engine braking, allowing you to adjust the parameters of starting and stopping currents in various modes:

At the time of launch, the current is limited to a given exceeding the nominal and is held on this value all the time to accelerate the engine. Typically, a limitation is used at the level of 200-300% of the rated current. The overload becomes insignificant, although its duration increases.

In this case, the current curve at the time of turning on the engine has a greater inclination, after which the Softstard goes into the current limitation mode.

This method of smooth start is used when connecting to low.power substations or generators to reduce the starting load, however, the starting point of the electric motor in this case is minimal. For devices devoid of the idle speed of the electric motor, it is impossible to use the formation of current with a gentle starting curve.

It is used with engines that directly lead the load, since otherwise their starting torque may be insufficient to terrify the rotor.

In this case, the device of the smooth start allows a short-term exceeding the starting current by several times (in fact direct switching is carried out), after a given time, the current decreases to two to three times exceeding the value.

When the engine is turned off, the voltage is completely removed from it, the rotation of the anchor continues by inertia. The easiest way to switch, applicable with small capacities and low inertia of the drive.

However, at the time of the rupture of the chain, there is a strong inductive release, leading to severe sincerity in contactors. On powerful electric motors, as well as with high operating voltages, this method of disconnecting unacceptable.

Used for a more smooth engine stop. It must be remembered that the torque of the engine is reduced non-linearly due to the quadratic dependence of the moment on the voltage, that is, the reduction of the moment occurs most sharply at the beginning of the curve.

The power outage occurs with a minimum current in the winding, respectively, switching switches practically do not wear out the formation of a spark between the contacts.

To reduce the loads when stopping, a controlled decrease in voltage is used:

Reducing the torque of the electric motor is close to linear. This method of controlling the electric motor is used in devices with high inertia of the drive.

When using such devices of smooth starting, launching work consists in setting the desired type of starting current curve and, in the case of using current generation or accelerated start, setting the duration of the temporary interval of the initial section of the curve.

The use of smooth starting devices allows you to automate the start-up mode, but its main minus remains-either you have to lay the possibility of the idle of the electric motor in the device, or allow short-term overload of the network, unwinding the motor and load with a kik start.

Smooth start. why is it needed

To reduce the exorbitant load on the mechanics of the power tool during start.up, measures may be taken by power supply. Instead of supplying a full voltage from the source (electric network) to the electric motor, a low voltage can be supplied using smooth start. But where to get it? We are talking about massive use. In some cases, specialists and craftsmen could solve this problem, but most ordinary consumers were inaccessible to this.

There are three ways to limit the starting moment of the power tool and achieve a smooth start:

The first method was used for a very long time, but it is not economical and inconvenient.

It can be used both on constant and on alternating current.

A significant part of the power is lost to heating the resistance of the rheostat. If the task is limited only by a smooth start, then this is quite tolerant. If in this way to adjust the working speed of the electric motor, then this is excessive environmental heating and electricity consumption. In any case, the device is bulky.

The second method is much better and more economical. Suitable only for alternating current. It can also increase electrical safety when working with electric tools. The disadvantage is that the classic transformers are now very expensive. Even with independent manufacture, since they are spent a lot of expensive copper. The device is also quite large and heavy.

The third method of smooth starting is the most modern and cheap. It relies on the massive use of semiconductors. At one time, in the research and commissioning of the industrial production of semiconductor devices, huge funds were invested. But the cheapness of the materials from which they are produced, and the mass of the release has already managed to recoup everything. Due to the low cost, such devices are available to all.

The main feature of semiconductor keys are no mechanical contacts and they work with a huge speed (switching frequency). The currents switched by them can reach large values, with high voltages in the disconnected state. At the same time, such devices practically do not heat up and do not consume unnecessary energy, like rheostats and are great for modern power tools.

Types of semiconductor keys

The resistance of an open key reaches millions of ohms, the current practically does not proceed through it.

The resistance of a closed key lies within the units and tenth shares of OMA.

Although a significant current may occur, too small voltage drops on the key to stand on it, according to the law of Joule-Lenz, a lot of warmth. In both cases, it remains almost cold.

This applies to any of the types of power keys, of which there are three:

Tiristors first appeared the first. With their help, the power in alternating current circuits was regulated, controlling the phase of unlocking the device.

By adjusting the phase of the control voltage (duration T1), you can influence at the time of unlocking the simistor in each half.period (T3) and thus, to the share of the energy that enters the load and, accordingly, to the electric motor.

With the advent of powerful field transistors with an isolated MOP-Razvor (metal-Okisel-Winner, or in the English Metal-Oxide-Semiconductor Field Effect Transistor), the current in the circuit began to control, changing the width of the opening pulses. This method is very effective in direct current circuits, for which it is first straightened, and is used in welding inverters, frequency converters, etc.D.

For the most powerful power tools, IGBT is used. bipolar transistors with an isolated shutter. This is a combination of a field transistor with bipolar.

To regulate the electric motor, the already established, long.applied solution on the simystory is currently used. advanced solutions are not yet very common.

How to make a smooth start yourself

Due to the simplicity of the scheme, the device of smooth starting the electric motor on the simistor is not difficult to assemble. It is made from available details. It is best to do it on the printed circuit board, so nothing will hang out and close. Simistor needs to be fixed on a heat heating radiator made of aluminum. It is better if it is a factory radiator designed for a power of 10-30 watts. Then it is suitable for power tools with a capacity of 1000-1200 watts.

The calculation of the radiator is very easy to calculate by current. About 1 falls on the Simistor.5-2 volt voltage when it is open. We get the current division of power into network voltage. For example, a power tool with a rated capacity of 1200 W: 1200/220 = 5.45 amperes. Multiply by 2, we get 11 watts.

Typically, in a selling power tool, the power restriction circuit is hidden somewhere in the handle or corner of the corner grinder or drill. There is no way to place a normal radiator. With frequent starting, it overheats and does not perform its functions. Only a good professional power tool has a normal device to limit the starting moment and speed control.

Note: The module of smooth starting for power tools is best made in a box with a socket. Do not take too small outlet boxes too. It is difficult to place a normal radiator for the simistor there. Without a radiator from the device there will be no practical benefit! When assembling a radiator with a device, it is necessary to ensure the purity of mating surfaces and a thin layer of thermal conductive paste (KTP-8 or an import analogue).

The radiator must be fixed on the same board on which the rest of the details are collected. The board is placed in a box of suitable size and quite strong. Such boxes can be bought in electrical goods or made from sheet plastic. A clean empty can of glue, paints with a screw or tightly closing lid may come up. It should be strong and unprecedented.

The socket mounted in the device should be designed for the rated current of the used electric motor. A similar story with a network cord.

IMPORTANT! If the power tool is equipped with a speed regulator, its handle should be securely isolated. The device is under voltage of the network and may turn out to be source of current in case of poor insulation.

It is useful to cover the printed circuit board after installation with nitrolak to protect against moisture. The principal scheme and the analysis of its work in the next section.

Smooth launch on the KR1182PM1 microcircuit

This is a microcircuit for production power tools that is produced by NTC SIT CJSC (g. Bryansk). It can be purchased in retail in many online stores. Also the new name K1182MP1R.

The microcircuit can be used without an external simistor during the operation of an electric motor for a load of up to 150 watts. This is too little for the power tool, but you can use a more powerful simistor, which will increase the control power to 1-1.5 kW. The scheme with its use is shown below:

Inside the chip is the control signal amplifier. This signal is formed at conclusions 3 and 6 of the microcircuit. The phase of unlocking the systemist is proportional to the voltage between conclusions 3 and 6, which can change in the range from 0 to 6 V. At zero, the load is disabled. When turning on, the capacitor actually accurately closes the control circuit. But it is quite quickly charged and this forms the smoothness of acceleration.

The resistor R1 allows the capacitor C1 to reduce pauses between inclusion faster. With full voltage, the load works with a power close to the nominal. This voltage is created by the microcircuit itself, and the external circuit only “shakes” it in order to influence the phase of the backbone of the systemist in each semi.period of the network voltage.

S1 switch can be used instead of a switch operating in the break in the network circuit. Only it works the other way around, when opening, the electric motor starts, and when the closure is disconnected. The current in the circuit of this switch is very small and you can use any microswitch. However, there should be a way to quickly turn off the power tool in any case! That is, you can’t do without an emergency network switch.

The use of a variable resistor in place R1 will more or less smoothly adjust the speed of the electric motor. Such a function, in addition to the smooth start, can be very useful when working with various materials that require their processing speed.

Typically, the time of the smooth start of the tool can be limited in the range of 0.thirty.5 sec. This provides a significant increase in the service life of the device. If the power tool is powerful and resourceful, it can unexpectedly tear it out of the employee’s hands with all unpleasant consequences. In such cases, you need an even more smooth start. You can choose a suitable dispersal delay using a graph shown below:

These data were obtained in the NGSPICE program based on the characteristics taken from the manufacturer’s documentation. In addition, they were tested in practice, with a 1500 W corner grinding machine and showed a good coincidence.

Simistor VS1 can be taken as BT139-600 (Philips), TS106-10-6 (SZTP), BTB10-600BWRG (ST Microelectronics) or other similar. Type K50-35 capacitors for operating voltage 50 V, with a capacity of 1 MF (C2.3) and 5-100 MF for C1. Resistor R2 Type MLT-0.5. It is also advisable to use a rated current fuse, which is 15-20% higher than the rated current of the estimated load, it is desirable in the circuit.

An example of installing a smooth launch of an electric motor on an angular grinder:

other methods

Among other methods of smooth start for power tools, the use of transformers can be noted. For example, there will be a rather universal Latra for 1-1.5 kW. Although this is a rather heavy device, it can help out if it is at hand, then you will not have to collect another device.

Sometimes, parallel sets of capacitors are used as a “cold” resistance in alternating current, using their reactive resistance at a frequency of 50 Hz:

Sources:

https://101benzopila.ru/kak-ustanovit-plavnyj-pusk-na-cirkularku/
https://molibden-wolfram.ru/plavnyj-pusk-dla-elektroinstrumenta-svoimi-rukami-shema-ustrojstvo-elektrodvigatela-na-simistore/
https://morflot.su/kak-sdelat-plavnyj-pusk-dlja-cirkuljarnoj-pily/
https://101benzopila.ru/kak-sdelat-plavnyj-pusk-na-torcovku/
https://molibden-wolfram.ru/kak-sdelat-plavnyj-pusk-na-cirkularnoj-pile/
https://labequip.ru/kak-sdelat-plavnyj-pusk-na-cirkularnoj-pile/
https://tex16.ru/instrumenty-i-prisposobleniya/blok-plavnyj-pusk.html
https://101benzopila.ru/kak-sdelat-plavnyj-pusk-na-cirkularnoj-pile/
https://morflot.su/plavnyj-pusk-dlja-jelektropily/

Articles circular, integral, make, smooth, start