Capítulo 1:Fundamentos de Electrónica y Mecánica
Capítulo 1: Fundamentos de Electrónica y Mecánica
En este capítulo presentamos los fundamentos de los sistemas eléctricos y mecánicos y sus componentes. Comenzamos primero con componentes eléctricos básicos: Resistor, Condensador e inductor. Luego, exploramos dispositivos semiconductores como Diodos, transistores, amplificadores operacionales, componentes lógicos y circuitos.
En diodos, presentamos diferentes tipos de diodos utilizados principalmente en robótica tales como diodos zener, diodos emisores de luz (LED), fotodiodos y sus aplicaciones. A continuación, introducimos la teoría de transistores y los tipos de transistores en su mayoría utilizados en robótica y sus aplicaciones. Se discuten los transistores bipolares (BJT) y transistores de efecto de campo (FET). La discusión continúa sobre componentes eléctricos especiales a saber, amplificadores operacionales (OPAMP). La aplicación más común de OPAMPS. Finalmente, discutimos sistemas digitales y sus componentes básicos tales como puertas lógicas, flip-flops, registros, y algunas circuitería diseñada con estos componentes.
En la sección de Sistemas mecánicos se analizan componentes mecánicos tales como engranajes, poleas, cadenas, levas, trinquetes y trinquete, rodamientos, accionamientos de cadena. Estos componentes se introducen y ejemplos de robótica se dan aplicaciones relacionadas para cada componente.
En esta sección, exploramos componentes eléctricos, dispositivos semiconductores, Amplificadores Operacionales(OPAMP) y sus aplicaciones, y componentes de sistemas digitales. Hay algunos libros muy buenos que cubren análisis de circuitos eléctricos. También hay algunos buenos libros a nuestro alcance de Robótica.
Las resistencias, los condensadores y los inductores son componentes eléctricos básicos utilizados en circuitos electrónicos. Algunos de los componentes eléctricos y sus símbolos son dado en la Figura 1.1.
value of the resistor is often changed by a user by turning a knob or a dial. There are some special resistors designed to change in resistance when heated. They are called Thermistors and are used in temperature measuring circuits. The same idea is also used to design pressure sensors where a membrane is designed to be a resistor. The membrane resistance changes when it is deformed by the pressure in a chamber. Resistors generate heat and have a wattage rating relating the power level they can handle. The higher the wattage rating the more heat they can dis- sipate. There are standard wattage ratings such as 1/8, 1/4, 1/2, 1, more watts. In addition to the value and wattage, each resistor has a tolerance regarding their resistance. Standard resistors have 10-20% tolerance but spe- cial resistors can have tolerances around 1%. Depending on the application, the proper tolerance rate is chosen. These properties are often marked on the resistors using a color code. Sometimes, they are written on the resistor.
1.1.1.1.1 Resistor Color Code and Standard Resistor Values Fixed value resistors are color coded to indicate their value and tolerance. Some have their value written on them. There are three color coding systems: a 4 Band code, a 5 Band code, and 6 Band code. The standard color coding method for resistors has 10 colors to represent numbers from 0 to 9: black, brown, red, orange, yellow, green, blue, purple, grey, and white. The first two bands always represent the significant digits on a 4 band resistor. On a 5 and 6 band, the significant digits are the first three bands. The third band is the multiplier or decade which is multiplied by the resulting value of the significant digit color bands. For example, if the first two bands are brown (1) and orange (3) and the third band is red (2), this means 10 2 or 100. Then, this gives a value of 13 × 100, or 1300 Ohms. For the decade band, the gold and silver colors are used to divide by a power of 10 and 100 respectively, allowing for values below 10 Ohms. The tolerance of the resistor is represented by the next band. Four colors are used for the tolerance band: brown (+/-1%), red (+/-2%), gold (+/-5%), and silver (+/-10%). For example, if the tolerance band is silver, the true value of the resistor can be 10% more or less than 1300 Ohms. Thus, the actual value of the resistor can be from 1170 to 1430 Ohms. The sixth band on a 6 band resistor reveals the temperature coefficient of the resistor, measured parts per million per degree Centigrade (PPM/C). Seven colors are used for the temperature coefficient: white (1), purple (5), blue (10), orange (15), yellow (25), red (50), and brown (100). The most popular color is brown (100 PPM/C) and will work for normal temperature conditions. The other colors are used for temperature critical applications. Table 1.1 represents all the colors and their meaning depending on their location on resistors. Figure 1.2 is a 6 band resistor with 27 KOhms, 10% tolerance, and the temperature coefficient of 50 PPM/C. Since the sizes of the electronic components are shrinking or changing in
#TABLE 1.1
