To control a stepper motor, you have to energize each winding individually in a specific and timed order. The energizing is accomplished by a driver circuit (an amplifier). The timing is performed by an indexer circuit and the objective (go forward, go backward, brake, coast, etc. ) is controlled by some external user interface, such as a computer
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or joystick. The figure below shows this process. The circuits for driving unipolar and bipolar stepper motors differ because bipolar stepper motors don`t have a "center tap. " However, it is possible to use bipolar drivers to drive unipolar steppers after some small modifications. Care must be taken in the driver circuit to protect against voltage spikes. Because the motor windings are inductors, switching off the power to the winding produces a short burst of voltage. To protect against this, always put a diode in parallel with the winding, making sure the diode can handle the winding current. This is shown in the following figure. For the switches, any kind of switching technology can be used. The following figure shows two such switches. The first one uses a power darlington transistor and the second one uses a power field effect transistor. For driving a full stepper motor, with multiple coils, you can either build each of the above circuits individually, or you can use a integrated chip. One such chip is the DS2003, which is a darlington array, and is shown below. This chip can be used when the total current to each winding is less than 500 milliamps. Bipolar stepper drivers use H-bridges to energize the windings of the motor. H-bridges allow you to choose the direction of the current through the winding. Using an H-bridge configuration, there are four transistors for each winding as shown in the first figure below....
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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