Showing posts from September, 2015

Power switch as current amplifier

This article has tendency to explain why microcontroller (MCU) devices are not good enough to directly drive devices like DC motors or any other high current load. Below picture shows the electrical concept of the port pin related to the microcontroller device. It is not concrete example of some specific MCU port (but it is much close r to the 8051 pin port configurations), it is an example, which means that each time, we have to take a look into MCU specification to see how ports are organized and configured, before we make a design decision. Figure #1: pin - electrical concept In the center of the pin configuration, there is a flip-flop, electrical device with capabilities to memorize one bit of information: 1 or 0, and belongs to the class of the bistable multivibrators , a basic RAM memory building block. It is a D type of flip -flop, where D input is connected to the data-bus together with central processor unit (CPU). Also, three control signals are presente