Drive Stepper Motor | Electronic Project Circuits

Posts Tagged ‘drive stepper motor’

Basic Stepper Motor Driver by 74194

The following diagram is for the main circuit of the motor driver. A testing version is shown later on this page. The testing circuit is laid out differently and shows the SN7474 in logic block form and LED’s are used to indicate the motor coils being switched.
#The 555 astable oscillator produces a series of CLOCK pulses that are fed to PIN 11 of the SN74194 integrated circuit.
#Each time the CLOCK pulse goes HIGH (positive) the HIGH state at the SN74194′s OUTPUT terminals, (PIN’s 12, 13, 14, 15), is shifted either UP or DOWN y one place. Refer to the “Stepper Motor Driver Waveforms” diagram.
The direction of this shifting is controlled by switch S2. When S2 is in the center OFF position the HIGH output state will remain in its last position and the motor will be stopped.

View example about Stepper Motor Driver kit. It is build very easy and inexpensive.

When the base of Q6 is LOW the shifting will be PIN 12 – 15 – 14 – 13 – 12 .etc.
When the base of Q7 is LOW the shifting will be PIN 12 – 13 – 14 – 15 – 12 .etc.
The direction of the pulse shifting determines the direction of motor rotation.
#The pulses from the OUTPUT’s of the SN74194 are fed to four segments of the ULN2003 Driver. When the input of a segment is HIGH, its darlington transistor will turn ON and its OUTPUT will conduct current through one of the motors coils.
#As the coils of the motor are turned ON in sequence the motor rotates to follow these steps. Refer to following diagrams

Read More Source:http://home.cogeco.ca/~rpaisley4/Stepper.html
Thank you.

Be the first to comment - What do you think? Posted by admin - March 19, 2008 at 6:17 pm

Categories: Electronic Control, Motor controller Tags: dc motor driver, drive stepper motor, TTL digital circuit

Driving Bipolar Stepper Motors by PIC16F84

Stepper motors are devices, which convert electrical impulses into discrete mechanical rotational movements. In a typical stepper motor, power is applied to two coils. Two stator cups formed around each of these coils, with pole pairs mechanically offset by Â½ a pole pitch, become alternately energized North and South magnetic poles. Between the two stator-coil pairs the offset is Â¼ of a pole pitch. The permanent magnet rotor has the same number of pole pairs as the stator coil section. Interaction between the rotor and stator (opposite poles attracting and like poles repelling) causes the rotor to move Â¼ of a pole pitch per winding polarity change. Motors are available in either 2 coil (bipolar) or 4 coil (unipolar) windings. In the unipolar version, the coils are bifilar (two side by side wires) wound on each stator half and opposite ends of each pair are connected together to form a center tapped coil. With this method, the flux is reversed by powering either one end or the other of the bifilar coil pair with the center connected to common. For a bipolar motor, an external device referred to as an H-Bridge can be used to reverse the polarity of the winding and thus the flux. An H-Bridge can also drive a unipolar motor by not connecting the center tap (common) lead or using only one of the windings in the pair

Source:http://www.piclist.com/techref/piclist/jal/DrivingBipolarStepperMotors.htm

Be the first to comment - What do you think? Posted by admin - February 4, 2008 at 7:38 pm

Categories: Microcontroller, Motor controller Tags: drive stepper motor, pic-microcontroller, PIC16F84

Full-featured Dual H-bridge

Probably the simplest, reversible drive circuit is the H-Bridge. Some BEAMbots use H-bridge motor drivers; many more use an H-bridge variant of some sort. Here’s a simple conceptual schematic: Image A basic H-Bridge has 4 switches, relays, transistors, or other means of completing a circuit to drive a motor. In the above diagram, the switches are labeled A1, A2, B1, B2. Since each of the four switches can be either open or closed, there are 24 = 16 combinations of switch settings. Many are not useful and in fact, several should be avoided since they short out the supply current (e.g., A1 and B2 both closed at the same time). There are four combinations that are useful

Read More Source:http://www.solarbotics.net/library/circuits/driver_robinson.html
Thank you.