An Introduction to Electronics Drafting Using CAD Software

Short tutorial on how to install EDA or eCAD software — Fritzing:

Objective

This lab is two pronged: first, practice designing on eCAD software "Fritzing" circuit problem sets, and, second, test these designs on physical bread boards.

Description

21st century have begun to oversee devices such as Glucose meters, Smart Phones and Tablets, Implanted Artifical Pacemakers, Digital Film Video and Film Production, and much more. Often the price of advanced electrical equipment are high. Though the materials used to manufacture them are cheap, yet the labour hours required to design, test and industrially mass produce is immense.

Nevertheless, prices of digital equipment decreases overtime. This is a direct result of global competition between companies to produce same products, which leads to effcient ways to design, fabricate, manufacture, and most importantly test fundamental building blocks of modern electronic equipment:

• PCBs - Printed Circuit Boards
• ICs - Integrated Circuits

Intel made it's mark from offering faster computer chips with upgrades from Pentium 1 to 2, 3, 4, Dual Core, Quad Core, i7, firstly, through better circuit topology and VLSI drafting, and, secondly, accurate micro-, nano- scale fabrication technologies. Skills and expertise in eCAD drafting allows you to realize your ideas for new hardware into reality. Plus, it is the one of the two bottle necks that can accelerate or slow more compact and powerful circuits. Aside Intel, other popular Electronics and Hardware producers investing in eCAD or EDA are AMD, Samsung, LG, Sony, Apple and much more. Figure 1 and 2 shows you electronic circuits before and after the advent of eCAD; do you notice the differences in hardware arangement with and without EDA?

Figure 1 A board inside an electronic eqiupment of the 1960. Hand drawn schemtics for very large circuits were useful form of communication to the manufacturer, but it prevented simulation and pre-manufacturing prototyping, resulting in bulky and not compact boards.

Figure 2 Modern board manufactured after full schematic was designed and optimized via EDA. Resulting boards are compact, tidy and have easier maintenance due to modular placement of working circuit blocks.

Figure 3 Magified view of paths between circuit elements and operational blocks in a Printed Circuit Board (PCB) circuit, which before the advent of EDA were physical wires as seen in Figure 1.

Software Tools

EDA tools are similar to productivity software. They are sold by software engineering companies, who are either for-profit and closed-source, or for-profit and open-source, or not-for-profit. Both open-source and closed-source CAD tools are used in industry, the former is more popular in academia and research, the later in private electrical producers. Two industry standards currently are:

• Fritzing
• KiCad

Exercise — Drafting a Light Switcher

In this exercise you prototype your first light or LED switcher. This is your first design with eCAD software "Fritzing". Therefore, the circuit you will design is most basic to keep you in ease.

Materials

The LED switcher consists of:

Figure 4 through 14 visually guides you to make your circuit schematic, real-world view or breadboard view, pcb view.

This visualization allows you to design efficient designs when the proejct is large scale. Your first drawing of the LED switcher is very small scale, hence it may seem with this exercise designing in advance is optionsl. However, with all real life electrical design engineering, without proper drafting, you have 100 percent guarantee of making faulty circuit giving you wrong, or at worst, no result at all.

Say, this circuit was being used as a buzzer notifier in a game show, like Jeopardy, it would be manufactured to go along with other circuitry at the podium: buzzer alarm, points displayer, etc. The LED switcher would be converted to a PCB design, before it is professionally manufactured. Figure below shows you how you accomplish this in Fritzing.

Keep in mind while you engineer your electrical technologies:

• Mistake free designs happen because of good drawing practices during schematic process.
• Professionals always prototype, visualize the circuit on breadboard and/or PCB, then simulate it. Try simulating this LED switcher at this open-source, free, simulator.
• Famous design engineers always keep notes on computer or hand-written notebooks of their work.

Happy designing!

Further Readings

To have a deepened knowledge in Automated Electronic Drafting, you should first gain a "knowledge scaffold and learning directions" of powerful math, science, computer technologies and engineering. Learn more as a student or teacher from free schools:

• Khan Academy World
• MIT Open Cours eWare
• Harvard, MIT, Berkeley, UTexas Sys Edx
• Coursera
• Udacity

Once you are feel confident, please Search with keywords "Prototyping Electronic Circuits", "Printed Circuit Board Fundamentals", "Integrated Circuit VLSI", "Circuit Topology", "History of Electronics"at UOIT Library or Open Textbooks and Open Encyclopediae:

• College Open Textbooks
• Wikibooks Engineering



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