Motor Driver Circuit Using Transistor

Actually we can t say it as a motor driver as it can just toggle motor on or off rather than controlling the motor speed or direction.

Motor driver circuit using transistor.

To the collector of the transistor the dc motor is connected. Because the single transistor motor driver was able to control the speed of motor. It is the simple and elegant solution to all motor driving problems. But the driver circuit for a bipolar stepper motor requires an h bridge type connection.

The h bridge motor driver circuit this circuit is called h bridge because the mosfets form the two vertical strokes and the motor forms the horizontal stroke of the alphabet h. Also this motor driver dose not cost any more than 1 25 usd making it super cheap. The name h bridge refers to the look of the connection consisting of four transistors and a motor in the center forming the letter h. Let in be the input to the base of the transistor.

An h bridge is an arrangement of transistors that allows a circuit full control over a standard electric dc motor. If you want to rotate your motor in only one direction then this is the easiest way to do so. Its circuit is shown below. Using transistor single direction control.

The driver circuit for a unipolar stepper motor can be constructed with the help of few transistors or a darlington transistor ic like uln2003. Bridge transistor motor driver as figure 5 we use the four transistors to connected into the h bridge circuit. But unable to control direction of the motor. Here power transistor is used as a switch to turn a motor on or off depending upon the applied voltage at base.

The bd6xx range is an npn darlington with a collector current rating of 4 amperes and there is a wide range of transistors available for use in this application. An h bridge is a simple electronic circuit consisting of four switching elements like transistors bjt or mosfet that can drive a motor in both the directions without switching the leads. Transistor based dc motor driver circuit is one of the simple dc motor driver circuit. Stepper motor driver using bi polar transistors this stepper motor driver circuit uses the bd681 bi polar transistors for switching current to the coils.

The same motor driver circuit is used in making a simple line follower robot. The classic beginner s dc motor driver circuit that appears in every electronics textbook is the bipolar transistor h bridge. And add a diode to protect the electricity that may flow backward from the motor. So we need a h bridge of transistors in order to control speed as well as direction of the motor efficiently.

We use the four transistors as a switch controller. Hence we use h bridge ics like l293d to drive bipolar stepper motors. The direction can be changed easily and the speed can be controlled.