This DIY circuit can be used as a speed controller for a 12V DC motor with a current rating of up to 5A, or as a dimmer for 12V halogen and LED lamps up to 50W. Control is carried out using pulse width modulation (PWM) at a pulse repetition rate of about 200 Hz. Naturally, the frequency can be changed if necessary, selecting for maximum stability and efficiency.

Most of these structures are assembled according to a much simpler scheme. Here we present a more advanced version that uses a 7555 timer, a bipolar transistor driver and a powerful MOSFET. This design provides improved speed control and operates over a wide load range. This is indeed a very effective scheme and the cost of its parts when purchased for self-assembly is quite low.

PWM controller circuit for 12 V motor

The circuit uses a 7555 Timer to create a variable pulse width of about 200 Hz. It controls transistor Q3 (via transistors Q1 - Q2), which controls the speed of the electric motor or light bulbs.

There are many applications for this circuit that will be powered by 12V: electric motors, fans or lamps. It can be used in cars, boats and electric vehicles, in model railways and so on.

12 V LED lamps, for example LED strips, can also be safely connected here. Everyone knows that LED bulbs are much more efficient than halogen or incandescent bulbs and will last much longer. And if necessary, power the PWM controller from 24 volts or more, since the microcircuit itself with a buffer stage has a power stabilizer.

AC Motor Speed ​​Controller

PWM controller 12 volt

Half Bridge DC Regulator Driver

Mini drill speed controller circuit

ENGINE SPEED CONTROL WITH REVERSE

Hello everyone, probably many radio amateurs, like me, have more than one hobby, but several. In addition to designing electronic devices, I do photography, video shooting with a DSLR camera, and video editing. As a videographer, I needed a slider for video shooting, and first I’ll briefly explain what it is. The photo below shows the factory slider.

The slider is designed for video shooting on cameras and video cameras. It is analogous to the rail system used in wide-format cinema. With its help, a smooth movement of the camera around the object being photographed is created. Another very powerful effect that can be used when working with a slider is the ability to move closer or further from the subject. The next photo shows the engine that was chosen to make the slider.

The slider is driven by a 12-volt DC motor. A diagram of a regulator for the motor that moves the slider carriage was found on the Internet. The next photo shows the power indicator on the LED, the toggle switch that controls the reverse and the power switch.

When operating such a device, it is important that there is smooth speed control, plus easy inclusion of engine reverse. The speed of rotation of the motor shaft, in the case of using our regulator, is smoothly adjusted by rotating the knob of a 5 kOhm variable resistor. Perhaps I am not the only one of the users of this site who is interested in photography, and someone else will want to replicate this device; those who wish can download an archive with a circuit diagram and printed circuit board of the regulator at the end of the article. The following figure shows a schematic diagram of a regulator for an engine:

Regulator circuit

The circuit is very simple and can be easily assembled even by novice radio amateurs. Among the advantages of assembling this device, I can name its low cost and the ability to customize it to meet your needs. The figure shows the controller's printed circuit board:

But the scope of application of this regulator is not limited to sliders alone; it can easily be used as a speed regulator, for example, a machine drill, a homemade Dremel powered by 12 volts, or a computer cooler, for example, with dimensions of 80 x 80 or 120 x 120 mm. I also developed a scheme for reversing the engine, or in other words, quickly changing the rotation of the shaft in the other direction. To do this, I used a six-pin toggle switch with 2 positions. The following figure shows its connection diagram:

The middle contacts of the toggle switch, marked (+) and (-), are connected to the contacts on the board marked M1.1 and M1.2, the polarity does not matter. Everyone knows that computer coolers, when the supply voltage and, accordingly, the speed are reduced, make much less noise during operation. In the next photo, the KT805AM transistor is on the radiator:

Almost any medium and high power n-p-n structure transistor can be used in the circuit. The diode can also be replaced with analogues suitable for the current, for example 1N4001, 1N4007 and others. The motor terminals are shunted by a diode in reverse connection; this was done to protect the transistor during switching on and off moments of the circuit, since our motor has an inductive load. Also, the circuit provides an indication of the inclusion of the slider on an LED connected in series with a resistor.

When using an engine of greater power than shown in the photo, the transistor must be attached to the radiator to improve cooling. A photo of the resulting board is shown below:

The regulator board was manufactured using the LUT method. You can see what happened in the end in the video.

Video of work

Soon, as soon as the missing parts, mainly mechanics, are acquired, I will begin assembling the device in the case. Sent the article Alexey Sitkov .

Diagrams and overview of 220V electric motor speed controllers

To smoothly increase and decrease the shaft rotation speed, there is a special device - a 220V electric motor speed controller. Stable operation, no voltage interruptions, long service life - the advantages of using an engine speed controller for 220, 12 and 24 volts.

• Why do you need a frequency converter?
• Scope of application
• Selecting a device
• IF device
• Types of devices
  • Triac device
• • Proportional Signal Process

Why do you need a frequency converter?

The function of the regulator is to invert the voltage of 12, 24 volts, ensuring smooth start and stop using pulse width modulation.

Speed ​​controllers are included in the structure of many devices, as they ensure the accuracy of electrical control. This allows you to adjust the speed to the desired amount.

Scope of application

DC motor speed controller is used in many industrial and domestic applications. For example:

• heating complex;
• equipment drives;
• welding machine;
• electric ovens;
• vacuum cleaners;
• sewing machines;
• washing machines.

Selecting a device

In order to select an effective regulator, it is necessary to take into account the characteristics of the device and its intended purpose.

1. Vector controllers are common for commutator motors, but scalar controllers are more reliable.
2. An important selection criterion is power. It must correspond to that permitted on the unit used. It is better to exceed for safe operation of the system.
3. The voltage must be within acceptable wide ranges.
4. The main purpose of the regulator is to convert frequency, so this aspect must be selected according to the technical requirements.
5. You also need to pay attention to the service life, dimensions, number of inputs.

IF device

• AC motor natural controller;
• drive;
• additional elements.

The circuit diagram of the 12 V engine speed controller is shown in the figure. The speed is adjusted using a potentiometer. If pulses with a frequency of 8 kHz are received at the input, then the supply voltage will be 12 volts.

The device can be purchased at specialized sales points, or you can make it yourself.

AC speed controller circuit

When starting a three-phase motor at full power, current is transmitted, the action is repeated about 7 times. The current bends the motor windings, generating heat over a long period of time. A converter is an inverter that provides energy conversion. The voltage enters the regulator, where 220 volts are rectified using a diode located at the input. Then the current is filtered through 2 capacitors. PWM is generated. Next, the pulse signal is transmitted from the motor windings to a specific sinusoid.

There is a universal 12V device for brushless motors.

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The circuit consists of two parts - logical and power. The microcontroller is located on a chip. This scheme is typical for a powerful engine. The uniqueness of the regulator lies in its use with various types of engines. The circuits are powered separately; the key drivers require 12V power.

Types of devices

Triac device

The triac device is used to control lighting, power of heating elements, and rotation speed.

The controller circuit based on a triac contains a minimum of parts shown in the figure, where C1 is a capacitor, R1 is the first resistor, R2 is the second resistor.

Using a converter, power is regulated by changing the time of an open triac. If it is closed, the capacitor is charged by the load and resistors. One resistor controls the amount of current, and the second regulates the charging rate.

When the capacitor reaches the maximum voltage threshold of 12V or 24V, the switch is activated. The triac goes into the open state. When the mains voltage passes through zero, the triac is locked, and then the capacitor gives a negative charge.

Converters on electronic keys

Common thyristor regulators with a simple operating circuit.

Thyristor, works in alternating current network.

A separate type is the AC voltage stabilizer. The stabilizer contains a transformer with numerous windings.

DC stabilizer circuit

24 volt thyristor charger

To a 24 volt voltage source. The principle of operation is to charge a capacitor and a locked thyristor, and when the capacitor reaches voltage, the thyristor sends current to the load.

Proportional Signal Process

Signals arriving at the system input form feedback. Let's take a closer look using a microcircuit.

Chip TDA 1085

The TDA 1085 chip pictured above provides feedback control of a 12V, 24V motor without loss of power. It is mandatory to contain a tachometer, which provides feedback from the engine to the control board. The stabilization sensor signal goes to a microcircuit, which transmits the task to the power elements - to add voltage to the motor. When the shaft is loaded, the board increases the voltage and the power increases. By releasing the shaft, the tension decreases. The revolutions will be constant, but the power torque will not change. The frequency is controlled over a wide range. Such a 12, 24 volt motor is installed in washing machines.

With your own hands you can make a device for a grinder, wood lathe, sharpener, concrete mixer, straw cutter, lawn mower, wood splitter and much more.

Industrial regulators, consisting of 12, 24 volt controllers, are filled with resin and therefore cannot be repaired. Therefore, a 12V device is often made independently. A simple option using the U2008B chip. The controller uses current feedback or soft start. If the latter is used, elements C1, R4 are required, jumper X1 is not needed, but with feedback, vice versa.

When assembling the regulator, choose the right resistor. Since with a large resistor there may be jerks at the start, and with a small resistor the compensation will be insufficient.

Important! When adjusting the power controller, you need to remember that all parts of the device are connected to the AC network, so safety precautions must be observed!

Speed ​​controllers for single-phase and three-phase 24, 12 volt motors are a functional and valuable device, both in everyday life and in industry.

Rotation controller for motor

On simple mechanisms it is convenient to install analog current regulators. For example, they can change the speed of rotation of the motor shaft. From the technical side, implementing such a regulator is simple (you will need to install one transistor). Suitable for adjusting independent speed of motors in robotics and power supplies. The most common types of regulators are single-channel and two-channel.

Video No. 1. Single-channel regulator in operation. Changes the rotation speed of the motor shaft by rotating the variable resistor knob.

Video No. 2. Increasing the rotation speed of the motor shaft when operating a single-channel regulator. An increase in the number of revolutions from the minimum to the maximum value when the variable resistor knob is rotated.

Video No. 3. Two-channel regulator in operation. Independent setting of the torsion speed of motor shafts based on trimming resistors.

Video No. 4. The voltage at the output of the regulator was measured with a digital multimeter. The resulting value is equal to the battery voltage, from which 0.6 volts have been subtracted (the difference arises due to the voltage drop across the transistor junction). When using a 9.55 volt battery, a change from 0 to 8.9 volts is recorded.

Functions and main characteristics

The load current of single-channel (photo 1) and two-channel (photo 2) regulators does not exceed 1.5 A. Therefore, to increase the load capacity, the KT815A transistor is replaced with KT972A. The numbering of the pins for these transistors is the same (e-k-b). But the KT972A model is operational with currents up to 4A.

Single channel motor controller

The device controls one motor, powered by voltage in the range from 2 to 12 volts.

Device design

The main design elements of the regulator are shown in the photo. 3. The device consists of five components: two variable resistance resistors with a resistance of 10 kOhm (No. 1) and 1 kOhm (No. 2), a transistor model KT815A (No. 3), a pair of two-section screw terminal blocks for the output for connecting a motor (No. 4) and input for connecting a battery (No. 5).

Note 1. Installation of screw terminal blocks is not necessary. Using a thin stranded mounting wire, you can connect the motor and power source directly.

Operating principle

The operating procedure of the motor controller is described in the electrical diagram (Fig. 1). Taking into account the polarity, a constant voltage is supplied to the XT1 connector. The light bulb or motor is connected to the XT2 connector. A variable resistor R1 is turned on at the input; rotating its knob changes the potential at the middle output as opposed to the minus of the battery. Through current limiter R2, the middle output is connected to the base terminal of transistor VT1. In this case, the transistor is switched on according to a regular current circuit. The positive potential at the base output increases as the middle output moves upward from the smooth rotation of the variable resistor knob. There is an increase in current, which is due to a decrease in the resistance of the collector-emitter junction in transistor VT1. The potential will decrease if the situation is reversed.

Electrical circuit diagram

Materials and details

A printed circuit board measuring 20x30 mm is required, made of a fiberglass sheet foiled on one side (permissible thickness 1-1.5 mm). Table 1 provides a list of radio components.

Note 2. The variable resistor required for the device can be of any manufacture; it is important to observe the current resistance values ​​​​for it indicated in Table 1.

Note 3. To regulate currents above 1.5A, the KT815G transistor is replaced with a more powerful KT972A (with a maximum current of 4A). In this case, the printed circuit board design does not need to be changed, since the distribution of pins for both transistors is identical.

Build process

For further work, you need to download the archive file located at the end of the article, unzip it and print it. The regulator drawing (termo1 file) is printed on glossy paper, and the installation drawing (montag1 file) is printed on a white office sheet (A4 format).

Next, the drawing of the circuit board (No. 1 in photo. 4) is glued to the current-carrying tracks on the opposite side of the printed circuit board (No. 2 in photo. 4). It is necessary to make holes (No. 3 in photo. 14) on the installation drawing in the mounting locations. The installation drawing is attached to the printed circuit board with dry glue, and the holes must match. Photo 5 shows the pinout of the KT815 transistor.

The input and output of terminal blocks-connectors are marked in white. A voltage source is connected to the terminal block via a clip. A fully assembled single-channel regulator is shown in the photo. The power source (9 volt battery) is connected at the final stage of assembly. Now you can adjust the shaft rotation speed using the motor; to do this, you need to smoothly rotate the variable resistor adjustment knob.

To test the device, you need to print a disk drawing from the archive. Next, you need to paste this drawing (No. 1) onto thick and thin cardboard paper (No. 2). Then, using scissors, a disc is cut out (No. 3).

The resulting workpiece is turned over (No. 1) and a square of black electrical tape (No. 2) is attached to the center for better adhesion of the surface of the motor shaft to the disk. You need to make a hole (No. 3) as shown in the image. Then the disk is installed on the motor shaft and testing can begin. The single-channel motor controller is ready!

Two-channel motor controller

Used to independently control a pair of motors simultaneously. Power is supplied from a voltage ranging from 2 to 12 volts. The load current is rated up to 1.5A per channel.

The main components of the design are shown in photo.10 and include: two trimming resistors for adjusting the 2nd channel (No. 1) and the 1st channel (No. 2), three two-section screw terminal blocks for output to the 2nd motor (No. 3), for output to the 1st motor (No. 4) and for input (No. 5).

Note:1 Installation of screw terminal blocks is optional. Using a thin stranded mounting wire, you can connect the motor and power source directly.

Operating principle

The circuit of a two-channel regulator is identical to the electrical circuit of a single-channel regulator. Consists of two parts (Fig. 2). The main difference: the variable resistance resistor is replaced with a trimming resistor. The rotation speed of the shafts is set in advance.

Note.2. To quickly adjust the rotation speed of the motors, the trimming resistors are replaced using a mounting wire with variable resistance resistors with the resistance values ​​indicated in the diagram.

Materials and details

You will need a printed circuit board measuring 30x30 mm, made of a fiberglass sheet foiled on one side with a thickness of 1-1.5 mm. Table 2 provides a list of radio components.

Build process

After downloading the archive file located at the end of the article, you need to unzip it and print it. The regulator drawing for thermal transfer (termo2 file) is printed on glossy paper, and the installation drawing (montag2 file) is printed on a white office sheet (A4 format).

The circuit board drawing is glued to the current-carrying tracks on the opposite side of the printed circuit board. Form holes on the installation drawing in the mounting locations. The installation drawing is attached to the printed circuit board with dry glue, and the holes must match. The KT815 transistor is being pinned. To check, you need to temporarily connect inputs 1 and 2 with a mounting wire.

Any of the inputs is connected to the pole of the power source (a 9-volt battery is shown in the example). The negative of the power supply is attached to the center of the terminal block. It is important to remember: the black wire is “-” and the red wire is “+”.

The motors must be connected to two terminal blocks, and the desired speed must also be set. After successful testing, you need to remove the temporary connection of the inputs and install the device on the robot model. The two-channel motor controller is ready!

THE ARCHIVE contains the necessary diagrams and drawings for the work. The emitters of the transistors are marked with red arrows.

DC motor speed controller diagram

The DC motor speed controller circuit operates on the principles of pulse width modulation and is used to change the speed of a 12 volt DC motor. Regulating the engine shaft speed using pulse-width modulation gives greater efficiency than simply changing the DC voltage supplied to the engine, although we will also consider these schemes

DC motor speed controller circuit for 12 volts

The motor is connected in a circuit to a field-effect transistor which is controlled by pulse-width modulation carried out on the NE555 timer chip, which is why the circuit turned out to be so simple.

The PWM controller is implemented using a conventional pulse generator on an astable multivibrator, generating pulses with a repetition rate of 50 Hz and built on the popular NE555 timer. The signals coming from the multivibrator create a bias field at the gate of the field-effect transistor. The duration of the positive pulse is adjusted using variable resistance R2. The longer the duration of the positive pulse arriving at the gate of the field-effect transistor, the greater the power supplied to the DC motor. And vice versa, the shorter the pulse duration, the weaker the electric motor rotates. This circuit works great on a 12 volt battery.

DC motor speed control circuit for 6 volts

The speed of the 6 volt motor can be adjusted within 5-95%

Engine speed controller on PIC controller

Speed ​​control in this circuit is achieved by applying voltage pulses of varying duration to the electric motor. For these purposes, PWM (pulse width modulators) are used. In this case, pulse width control is provided by a PIC microcontroller. To control the engine rotation speed, two buttons SB1 and SB2, “More” and “Less,” are used. You can change the rotation speed only when the “Start” toggle switch is pressed. The pulse duration varies, as a percentage of the period, from 30 to 100%.

As a voltage stabilizer for the PIC16F628A microcontroller, a three-pin KR1158EN5V stabilizer is used, which has a low input-output voltage drop, only about 0.6V. The maximum input voltage is 30V. All this allows the use of motors with voltages from 6V to 27V. The KT829A composite transistor is used as a power switch, which is preferably installed on a radiator.

The device is assembled on a printed circuit board measuring 61 x 52 mm. You can download the PCB drawing and firmware file from the link above. (See folder in the archive 027-el)

Based on the powerful triac BT138-600, you can assemble a circuit for an AC motor speed controller. This circuit is designed to regulate the rotation speed of electric motors of drilling machines, fans, vacuum cleaners, grinders, etc. The motor speed can be adjusted by changing the resistance of potentiometer P1. Parameter P1 determines the phase of the trigger pulse, which opens the triac. The circuit also performs a stabilization function, which maintains engine speed even under heavy load.

For example, when the motor of a drilling machine slows down due to increased metal resistance, the EMF of the motor also decreases. This leads to an increase in voltage in R2-P1 and C3 causing the triac to open for a longer time, and the speed increases accordingly.

Regulator for DC motor

The simplest and most popular method of adjusting the rotation speed of a DC motor is based on the use of pulse width modulation ( PWM or PWM ). In this case, the supply voltage is supplied to the motor in the form of pulses. The repetition rate of the pulses remains constant, but their duration can change - so the speed (power) also changes.

To generate a PWM signal, you can take a circuit based on the NE555 chip. The simplest circuit of a DC motor speed controller is shown in the figure:

Here VT1 is an n-type field-effect transistor capable of withstanding the maximum motor current at a given voltage and shaft load. VCC1 is from 5 to 16 V, VCC2 is greater than or equal to VCC1. The frequency of the PWM signal can be calculated using the formula:

F = 1.44/(R1*C1), [Hz]

Where R1 is in ohms, C1 is in farads.

With the values ​​indicated in the diagram above, the frequency of the PWM signal will be equal to:

F = 1.44/(50000*0.0000001) = 290 Hz.

It is worth noting that even modern devices, including those with high control power, are based on precisely such circuits. Naturally, using more powerful elements that can withstand high currents.

Adjusting the speed of electric motors in modern electronic technology is achieved not by changing the supply voltage, as was done before, but by supplying current pulses of different durations to the electric motor. PWM, which has recently become very popular, is used for these purposes ( pulse width modulated) regulators. The circuit is universal - it also controls the engine speed, the brightness of the lamps, and the current in the charger.

PWM regulator circuit

The above diagram works great and is attached.

Without altering the circuit, the voltage can be raised to 16 volts. Place the transistor depending on the load power.

Can be assembled PWM regulator and according to this electrical circuit, with a conventional bipolar transistor:

And if necessary, instead of the composite transistor KT827, install a field-effect IRFZ44N, with resistor R1 - 47k. The polevik without a radiator does not heat up at a load of up to 7 amperes.

PWM controller operation

The timer on the NE555 chip monitors the voltage on capacitor C1, which is removed from the THR pin. As soon as it reaches the maximum, the internal transistor opens. Which shorts the DIS pin to ground. In this case, a logical zero appears at the OUT output. The capacitor begins to discharge through DIS and when the voltage on it becomes zero, the system will switch to the opposite state - at output 1, the transistor is closed. The capacitor begins to charge again and everything repeats again.

The charge of capacitor C1 follows the path: “R2->upper arm R1 ->D2,” and the discharge follows the path: D1 -> lower arm R1 -> DIS. When we rotate the variable resistor R1, we change the ratio of the resistances of the upper and lower arms. Which, accordingly, changes the ratio of the pulse length to the pause. The frequency is set mainly by capacitor C1 and also depends slightly on the value of resistance R1. By changing the charge/discharge resistance ratio, we change the duty cycle. Resistor R3 ensures that the output is pulled to a high level - so there is an open-collector output. Which is not able to independently set a high level.

You can use any diodes, capacitors of approximately the same value as in the diagram. Deviations within one order of magnitude do not significantly affect the operation of the device. At 4.7 nanofarads set in C1, for example, the frequency drops to 18 kHz, but it is almost inaudible.

If after assembling the circuit the key control transistor gets hot, then most likely it does not open completely. That is, there is a large voltage drop across the transistor (it is partially open) and current flows through it. As a result, a lot of power is dissipated for heating. It is advisable to parallel the circuit at the output with high-capacity capacitors, otherwise it will sing and be poorly regulated. To avoid whistling, select C1, the whistling often comes from it. In general, the scope of application is very wide; its use as a brightness regulator for high-power LED lamps, LED strips and spotlights will be especially promising, but more on that next time. This article was written with the support of ear, ur5rnp, stalker68.