**1. Introduction**

Digital circuits represent logical possible values that combines the most basic building blocks of its configuration using the role of logic which defines the physical behaviour of the process. Its principles is formed from modularity of analog circuits that allows users to create circuits of mind-boggling complexity that are reliable and consistent [1, 2]. Digital circuits have become so popular and successfully that it can be used to produce programmable processor with fast and even running capabilities. Its importance is based on remarkable flexibility which can be implemented to produce a remarkable diversity of functions, which means that a device can do a lot of things based on its flexible programmability. The fundamental components includes AND, OR and the inverter (**Figure 1**). The flipflops is another storage device based on digital circuits that holds a logic value; the most common one is the D flipflop. One sure way of representing a digital circuit is using schematic diagrams that shows a collection of its components that are connected together with lines and adders. They are also designed by using hand-drawn methods during the 1980s [3–5]. Computed aided tools are developed to reduce the amount of effort necessary to stipulate circuits and verification of the output correctly.

memory. The processors includes internal storage capabilities (registers) that holds

*Modeling and Simulation of a DC Drive Integrated through a Demultiplexer*

In digital circuits, the demultiplexer represents one to many, which is one internal input to multiple outputs. By applying control signal the input is steered to the output. The 1–4 demultiplexer has 1 input bit, 2 control bit and 4 output pits (**Figure 3**). The data or information (D) bits is transferred or transmitted to the data bit of the output lines, depending on the value of the inputs AB, which are the control bits. The DC motors are distinguished by their ability to operate from possible direct current and work on their motor principles. The DC motors are basically electromechanical energy conversion devices that are essentially a *mm* of transfer between an input side and an output side [10, 11]. The parts mostly necessary for electromechanical energy conversion are the direct current log, the induction log and the synchronous logs, these are used extensively for rigorously energy conversion purposes. When electric energy are supplied to the conductor, the interaction of current flowing in the conductor produces mechanical force and energy. The extended force is exerted upon the conductor and presented as flux which is associated with the mechanical motion. The input load is the electrical energy, while the output load is the mechanical energy [12, 13]. The DC motors consists of sets of coils in permanent magnets or stator, these are connected to the demultiplexer. The stator are mostly stationary outside while the

motor are composed of windings connected to the external circuit through mechanical commutator. The value of mechanical force extracted upon the con-

X is the value of the current that could be flowing in the conductor.

*Force* ¼ *Dx x*ð Þ ∗ *L* where D is the density and L is the length of the conductor,

The chapter mostly discussed the configurations of a DC motor machine (**Figure 5**) integrated with a demultiplexer to produce an engine starter system with induced variables of electromagnetic flux [14]. The value of the induced current flowing through the armature is dependent upon the difference between the applied voltage and the counter voltage. The current due to this counter voltage tends to oppose the very cause for its production according to the opposite resultant response to the demultiplexer [15–17]. During simulation of the entire system, the outputs were re-evaluated at process time. In the demultiplexer, when a process is

intermediate data or information.

*DOI: http://dx.doi.org/10.5772/intechopen.89068*

**1.2 The demultiplexer**

ductor can be expressed as:

**Figure 3.**

**351**

*The DC machine circuit.*

**Figure 1.**

*The AND, OR and NOR gates, together with the flipflops. (a) The OR Gate with one output port. (b) rFlipFlop with two inputs and outputs. (c) The AND Gate with one output. (d) The NOR Gate with a single output.*

#### **1.1 Programmable processors**

The most important digital circuit is the programmable processors (PP) (**Figure 2**). The figure shows a simple generic processor and an additional memory device, which can be observed as an array of storage location, identified by an integer index known as ROM and RAM address. Each location in the memory is stored in a fixed-length integer processors with 32–64 bits [6, 7]. For the PP, we are going to be making use of the WashU-2 software and VHDL Language. The memory in the processors is used to save and store two types of information which includes the instructions and data [8, 9]. An example of the instruction could be two or more numbers together or transfer of a value between the processors and

**Figure 2.** *Diagram indicating a simple programmable processor with a RAM and ROM.*

memory. The processors includes internal storage capabilities (registers) that holds intermediate data or information.
