How To Connect An Angle Grinder Directly Without A Speed Controller

Angle grinder with soft start: device and connection of the starter angle grinder with soft start is an extremely convenient and safe tool on the farm. How to choose the right soft-start device? Is it possible to install such a function on an angle grinder yourself? What does adjusting the speed on an angle grinder mean?

Angle grinder with soft start: device and connection of the starter

how to connect an angle grinder directly without a speed controller
  1. Features and purpose
  2. Soft starter
  3. Tips for choosing
  4. How to connect?

An angle grinder or angle grinder is a very useful tool on the farm when working with various surfaces. Such a tool dramatically eases many tedious processes. It can be used to process, sand or cut metal, wood, stone or plastic materials. Most modern grinders are initially equipped with a soft start function. What is the use of this function?

Tips for choosing

How to choose the right angle grinder? To do this, it is worth using several basic criteria.

To choose the right tool, it is worth deciding on the specific type of work to be performed with this tool. Angle grinder can be of different types: network, with batteries, gasoline and pneumatic.

Network models are perhaps the most common. Such an angle grinder works from a home network, that is, from a simple outlet. Such models of the tool have high power, compactness and high rotation speed of the cutting discs.

Cordless devices are deprived of this disadvantage. They have a special mount for power supplies that are charged from the mains. After charging, you can work with such a tool without any wires. Typically, such an angle grinder has compact dimensions and small diameters of cutting discs. As a rule, such models are more expensive than standard tools. Also, the period of their operation is limited by the capacity of the power supply.

Gasoline models of grinders are rare. Such devices are large in size, because they need a fuel tank, as well as an internal combustion engine. Among the advantages, it is worth highlighting the high power of these models, a wide range of disk choices and autonomy. The negative aspects include their weight and volume, high noise levels and, of course, additional fuel costs for the operation of the device.

Pneumatic model angle grinder is often used for production purposes and very rarely for household work. This is an unusual angle grinder that runs on compressed air and needs a special compressor. For such models, the problem of overheating is completely eliminated, and the period of operation can be limited only by the human factor. Also, such models are the lightest and quietest.

For simple work on processing and grinding surfaces, light models of grinding machines with a small diameter of the cutting wheel are suitable. For work on cutting durable materials, it is worth choosing more powerful and, accordingly, bulky equipment with a large disc diameter. The diameters of the discs can be from 125 (minimum size) to 230 (maximum size) mm, that is, the range of sizes is quite wide. The universal blade diameter is 180 mm. Such a circle can both process surfaces and cut material.

When choosing a disc, it is worth conducting a careful visual inspection. Even minor damage and chips can lead to extremely sad consequences. By the way, almost 90% of accidents when working with an angle grinder are caused by a defect on the cutting discs.

Convenience of work is also an important selection criterion. The angle grinder should be equipped with comfortable handles, should not slip out of the palm and be heavy. Many angle grinders have an electronic relay to protect against power surges and overloads. This is a useful feature, so it is worth choosing a tool with this fuse.

Soft starter

On modern grinders, the soft start function is already installed, but some craftsmen independently supply their angle grinder with a soft start device. In principle, it is not so difficult to put a limiter.

You can purchase ready-made devices for soft start, or you can make such a device yourself. Below is one of the most famous schemes for a soft starter device.

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So, for the manufacture of a soft start system you will need:

  • Microcircuit KR1182PM1;
  • R1 470 Ohm R2 68;
  • C1 and C2 1 microfarad 10 volts;
  • C3 47 microfarads 10 volts.

The essence of the work of such a device is the following characteristics.

  • When the device is turned on, the voltage from the network begins to flow to the microcircuit (DA1).
  • Then the control capacitor starts to charge gradually. After that, the device reaches the desired voltage indicator. For this reason, the thyristors open in the microcircuit with a small delay. The period of this delay depends on the time it takes for the capacitor to fully charge.
  • Triac VS1 will also open gradually. This is because it is also controlled by thyristors.

These processes are carried out in periods that gradually become smaller. And for this reason, the voltage that is supplied to the motor of the angle grinder does not increase in jumps, but gradually. This allows the angle grinder to start smoothly.

The capacity of the capacitor C2 directly affects the time it takes for the motor to fully start to work. The capacitor, which has a capacity of 47 μF, starts the device in about 2-3 seconds. And at the moment when the angle grinder is turned off, the capacitor C1 is discharged using a 60 kΩ resistor R1. This happens in about the same time as turning on. The tool can then be run again for further work.

Diagram of the smooth start of the electric motor do-it-yourself angle grinder

Everyone who has used an angle grinder for more than one year, it broke. At first, each craftsman tried to repair the sparkling grinder himself, hoping that it would work after replacing the brushes. Usually, after such an attempt, the broken tool remains on the shelf with burned-out windings. And a new angle grinder is bought to replace it.

Drills, screwdrivers, hammer drills, milling cutters are necessarily equipped with a speed controller. Some so-called calibration grinders are also equipped with a regulator, while conventional angle grinders only have a power button.

Manufacturers do not deliberately complicate low-power angle grinders with additional circuits, because such a power tool should be cheap. It is clear, of course, that the service life of an inexpensive tool is always shorter than that of a more expensive professional one.

The simplest angle grinder can be upgraded so that the gearbox and armature winding wires are no longer damaged. These troubles mainly occur with a sharp, in other words, shock start of the angle grinder.

All modernization consists in just assembling the electronic circuit and fixing it in the box. In a separate box because there is very little space in the sander handle.

A proven, working diagram is laid out below. It was originally intended to adjust the incandescence of lamps, that is, to work on an active load. Its main advantage? Simplicity.

  1. The highlight of the soft starter, the schematic diagram of which you see, is the K1182PM1R microcircuit. This microcircuit is highly specialized, of domestic production.
  2. The acceleration time can be increased by choosing a larger capacitor C3. While charging this capacitor, the electric motor picks up speed to the maximum.
  3. There is no need to replace the resistor R1 with a variable resistance. The 68 kΩ resistor is optimally matched to this circuit. With this setting, you can smoothly start the angle grinder with a power of 600 to 1500 W.
  4. If you are going to assemble a power regulator, then you need to replace the resistor R1 with a variable resistance. A resistance of 100 kOhm or more does not lower the output voltage. By short-circuiting the legs of the microcircuit, you can completely turn off the connected angle grinder.
  5. By inserting a semiconductor VS1 of the TC-122-25 type, that is, at 25A, into the power circuit, you can smoothly start almost any commercially available grinder with a power from 600 to 2700 W. And there is a large margin of power in case the grinder is jammed. To connect grinders with a power of up to 1500 W, the imported semistors BT139, BT140 are enough. These less powerful electronic keys are cheaper.
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The semistor in the above circuit does not open completely, it cuts off about 15V of the mains voltage. This voltage drop does not affect the operation of the angle grinder. But when the semicistor heats up, the revolutions of the connected instrument are greatly reduced. This problem is solved by installing a radiator.

This simple circuit has one more drawback, its incompatibility with the speed control installed in the instrument.

A socket is screwed to the box and a cable with a plug is connected, which makes this design look like an extension cord.

If experience allows and there is a desire, you can assemble a more complex soft start circuit. The circuit diagram below is standard for the XS12 module. This module is installed in the power tool at the factory.

If you need to change the speed of the connected electric motor, then the circuit becomes more complicated: a trimmer is installed at 100 kOhm, and an adjusting resistor at 50 kOhm. Or you can simply and roughly introduce a 470 kOhm variable between the 47 kOhm resistor and the diode.

In parallel with the capacitor C2, it is desirable to connect a 1 MΩ resistor (it is not shown in the diagram below).

The supply voltage of the LM358 microcircuit is in the range from 5 to 35V. The voltage in the power supply circuit does not exceed 25V. Therefore, you can do without an additional Zener diode DZ.

Whichever softstarter you build, never turn on a connected tool under load. Any soft start can be burned if in a hurry. Wait for the angle grinder to unwind and then work.

Electric drill: device diagram

A drill in the household today is simply irreplaceable, almost all craftsmen have it in their arsenal. Some models include a percussion mechanism, which is shown by the diagram, which can be seen in Fig. 1. In this case, the device is more functional. The device can be seen from the diagram in Fig. 2, it shows the speed controller under the number 1; under the number 2 reverse; number 3 denotes a brush holder with the brush itself; 4 is the stator of the motor; 5 impeller designed to cool the engine; the gearbox is located under the number 6.

Tool motor device

The drill has a collector electric motor in the design, which includes 3 main components, among them:

  • Stator;
  • Anchor;
  • Carbon brushes.

Figure 1. Diagram of the percussion mechanism of the drill.

The first mentioned element is based on electrical steel, which is characterized by the quality of excellent magnetic permeability. It is made on the principle of a cylinder and has devices for mounting stator windings. The latter are contained there in the amount of two, and their location is opposite each other. The stator is firmly fixed in the main unit housing.

The rotor is represented by a shaft, the latter has a core made on the basis of the same steel. Along the latter, there are grooves spaced equally spaced. The windings are laid in a single wire and have taps, which are designed to be fixed to the collector plates. This forms an anchor that is composed of segments. The manifold is located on the shaft end and is securely fixed to it. During start-up, the rotor rotates in the inner space of the stator on bearings. Brushes move along the plates during the operation of the installation. They are based on graphite.

Triac regulator

The triac regulator, located in the start button, is responsible for the speed of the installation when the drill is turned on. This regulator is mounted in the button body and is located on a lining made of PCB. The board is equipped in such a way that it has small dimensions, which allows it to be fully positioned in the trigger space. After activating the power button in the regulator of the device, an immediate break occurs, at this moment the circuit is closed in a scanty period of time. And the regulator is not able to affect the voltage variation, however, it undergoes a change in the rms voltage level.

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In parallel with this, a sinusoidal voltage is supplied to the control electrode of the triac. In the period when its level is higher than the voltage of the operation of the triac, the latter opens, which indicates the closure of the circuit, at this moment the current flows through the load.

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The wiring diagram and the connection of the installation button in different models from different manufacturing plants may differ. The most simplified of all the circuits and the one that best shows the principle of operation is shown in Fig. 3. One wire from the power cord connects to the governor. The figure shows the electrical diagram of the apparatus, where reg. Rev. Speed regulator, 1st st. Exchange primary stator winding, 2nd st.Obm. Respectively, secondary, 1st brush. First brush.

In order not to get confused, it should be remembered that the speed governor and the reverse control system are represented by completely different components of the tool, which in some models even have separate bodies.

Figure 3: Typical Drill Speed ​​Controller

Only 2 wires are suitable for the speed controller. And the one that comes out of the speed controller is connected to the beginning of the stator primary. In the absence of reverse, the end of the primary would be conjugated with the rotor brush, and the second brush would be paired with the beginning of the stator secondary. The end of the secondary goes to the second wire of the cord, from which the drill is powered during operation.

The rotor starts to work in the other direction at the moment when the end of the primary is connected to the second brush. In the reverse system, a similar connection is carried out, for this reason the rotor brushes are mated with the stator windings through it. In fig. 4 shows the connection diagram of the apparatus reverse. Wires in the amount of 4 pcs. Go to the rotor brushes, those that have a gray color go to the end of the primary and the beginning of the secondary.

The system for adjusting the speed of the apparatus assumes the presence of a capacitor and the connection to the regulator of the wires that come from the outlet. If we take into account the installation from the example, then only two contacts are used, which are located below. In this case, the system is completely devoid of a capacitor, and the second wire of the cord is connected directly to the stator winding.

Tool motor device

The drill has a collector motor in its design, which includes 3 main components, among them:

  • Stator;
  • Anchor;
  • Carbon brushes.

Figure 1. Diagram of the percussion mechanism of the drill.

The first mentioned element is based on electrical steel, which is characterized by the quality of excellent magnetic permeability. It is made on the principle of a cylinder and has devices for mounting stator windings. The latter are contained there in the amount of two, and their location is opposite each other. The stator is firmly fixed in the main unit housing.

The rotor is represented by a shaft, the latter has a core made on the basis of the same steel. Along the latter, there are grooves spaced equally spaced. The windings are laid in a single wire and have taps, which are designed to be fixed to the collector plates. This forms an anchor that is composed of segments. The manifold is located on the shaft end and is securely fixed to it. During start-up, the rotor rotates in the inner space of the stator on bearings. Brushes move along the plates during the operation of the installation. They are based on graphite.

Electric drill: device diagram

A drill in the household today is simply irreplaceable, almost all craftsmen have it in their arsenal. Some models include a percussion mechanism, which is shown by the diagram, which can be seen in Fig. 1. In this case, the device is more functional. The device can be seen from the diagram in Fig. 2, it shows the speed controller under the number 1; under the number 2 reverse; number 3 denotes a brush holder with the brush itself; 4 is the stator of the motor; 5 impeller designed to cool the engine; the gearbox is located under the number 6.