Stepper Motor Drivers
This text is machine translated.
Stepper motors are now used in the field of automation. You

Ideal for all applications where precise positioning is required. Stepper motor drivers are used to drive and control them. See our guide to learn how they work and what to look for when you buy.
-
What was stepper motor?
-
Control of stepper motors with stepper motor drivers
-
Buying Criteria for Stepper Motor Drivers – What's it all about?
-
Our practical tip: Find the right tension
-
FAQ – Frequently Asked Questions about Stepper Motor Drivers
What was stepper motor?

Conventional electric motors are an integral part of drive technology. They are used to set something in motion, and by applying a voltage they are turned. Depending on the mechanical load, the rotation speed will drop higher or lower. However, they are not suitable for applications that require accuracy. In such cases, so-called stepper motors are the better choice, as they enable a targeted approach to certain points and precise positioning. Stepper motors can generate high torque even at low speeds, work very reliably and are part of many industrial and commercial applications. They are used, among other things, for controlling robots or in printers, in order to place color points side by side at very low intervals. Stepper motors are also used in the CNC control. CNC (Computerized Numerical Control) is an electronic process for controlling CNC machines that produce workpieces with the utmost precision. These include CNC milling, for example, which is used for engraving or milling 3D objects. Stepper motors are now also used in motor vehicles to control the flaps of heating or air conditioning systems, for example.

Stepper motors operate differently from DC or DC motors. A stepper motor is a brushless synchronous motor consisting of a rotating part, the so-called rotor, and a non-rotating part, the stator. The stator is equipped with coils that generate an electromagnetic field and whose windings are switched on and off in a targeted manner, whereby the rotor starts to rotate. The rotation angle can be influenced by controlling the coils. A revolution consists of a certain number of steps of the same size. Each individual step requires a pulse to be performed. As the pulse frequency increases, the step motion switches to a continuous rotation motion. As a rule, industrial motors generate 200 steps per revolution. In other words, to fully rotate the axis in the motor once, 200 discrete steps are required.
Depending on their design, several types of stepper motors can be distinguished: Reluctance stepper motors have a serrated soft iron rotor. They achieve a high speed and an exact step angle, but produce only a small torque. Permanent magnet stepper motors, on the other hand, are equipped with a rotor in the form of a cylindrical permanent magnet. They produce a higher torque than reluctance stepper motors, but work at less precise step angles. Hybrid stepper motors are, so to speak, a mixed form of reluctance and permanent magnet stepper motors. They produce a high torque, precise step angles and are today the most widespread.
Stepper motor control with stepper motor drivers

Stepper motors are brushless and therefore wear-free than conventional electric motors, but they must be controlled using a controller in order to be able to rotate. This is the task of stepper motor drivers. As the name suggests, they primarily have the function of driving the motor, but they also serve the targeted stepper motor control by controlling, for example, the rotational speed, direction of rotation, turning force or turning position.
Stepper motor drivers work together with a so-called stepper motor indexer or stepper motor controller, which is usually connected upstream. It provides step and direction control signals that the stepper motor driver receives and converts into electrical signals required to operate the motor. Via a suitable interface (e.g. RS-232 or RS-485), communication with the stepper motor indexer is ensured. It can be connected to a PC whose commands transform into the appropriate step and direction control signals and finally forward to the stepper motor driver. Versions for stand-alone operation are also available.

Stepper motor drivers influence the current flow that flows through the windings in the motor and ultimately determines how high or low the speed and torque are. Some drivers also have a built-in clock generator that allows the speed to be adjusted from the outside, for example by operating a joystick. The current flow rate and the time it takes to "energize" the windings depends on the inductance of the motor.
There is no fixed method of configuring motor drivers. The configuration is different depending on the driver and board. Often the corresponding software is used, but there is also the possibility to make settings via hardware. This is usually the case when one or more DIP switches are on the board.
In our online shop you will find a large selection of stepper motor drivers in the form of circuit boards, modules and step sticks, which are suitable for different application areas.
Our practical tip: Find the right tension
Many stepper motor drivers can generate a voltage that is higher than the rated motor voltage. The output voltage of the driver is proportional to torque and speed and should ideally be as high as possible. Finding the right voltage is not necessarily easy. In principle, it is recommended that the driver and motor are not operated immediately with maximum voltage, but rather start with a low voltage and gradually increase it. In this context, stepper motor drivers are practical, which have a current control. They prevent overcurrent by limiting higher voltages to the rated current of the motor.
Buying Criteria for Stepper Motor Drivers – What's it all about?
When selecting a suitable stepper motor driver, the maximum phase current must first be taken into account. Maximum phase currents are specified to counteract the development of heat in the coils of the motor. You can filter on this criterion in our online shop.
In order to prevent overheating and potentially resulting damage to the electronics, stepper motor drivers should ideally be equipped with a heat sink or fan. Some drivers simply switch themselves off automatically in case of too high heat generation. It is possible to retrofit drivers with a heat sink. However, it is important to ensure compatibility between the two components. Refer to the manufacturer's description.
Interfaces can be a decisive purchasing criterion if the stepper motor driver is to be controlled via a PC. Not every laptop or desktop PC has an RS-232 or RS-483 interface. In such cases, it makes sense to select a driver with a USB connection.
If you want to control your stepper motor driver with an Arduino or other microcontroller, make sure that the respective version is compatible with it. Relevant data can be found in the manufacturer's description.

FAQ – Frequently Asked Questions about Stepper Motor Drivers
What was closed loop stepper motors?
Closed-loop motors are opposite open-loop motors. Open Loop means as much as "open loop", which means that the driver does not receive any feedback during motor control. A loss of step is therefore not registered, which was the result of inaccurate positioning. Closed loop refers to a closed loop. Motors that function according to this principle provide position feedback and correct any errors, so that step losses cannot occur at all.
What was H-bridges?
H-bridges are used to control bipolar stepper motors that require a reversal of the operating current. A circuit consisting of H-bridges consists of 4 semiconductor switches (e.g. Transistors) and must be created for each winding.