Shield Using PNP Darlington Transistors (MEC157E)

This circuit was adapted from my book Robotics, Mechatronics and Artificial Intelligence (sold out) published in the United States. It can be used as a control shield for stepper motors in a mechatronics or robotics project or as a building block for simple projects. More power can be provided to stepper motors using the block suggested by Figure 1. This block is the Darlington version of the previous block MEC156E), where each transistor is on when the input (base) is set to the low logic level.

The recommended transistors need less than 1 mA to drive motors up to 1 A. If you want to drive more powerful motors, see other articles in this section for information about other Darlington transistors suitable for the task.


Figure 1    Shield using PNP Darlington transistors.
Figure 1 Shield using PNP Darlington transistors.