Componentes eletrônicos e Semicondutores

Electronic Components

If youre looking to build your own circuit boards, then youll need a collection of transistors and varactors to get the job done. You might want to keep a large supply of components around in case you ever need to repair devices that have seen better days. A breadboard, some test equipment, and a healthy supply of ferrite coils might be all you need to bring an amplifier circuit back up to speed.

Analog components can take measurements of specific voltages whenever signals pass through a circuit. Digital electronics measure whether or not a voltage is there. If there is electricity running through a series of diodes, then digital components will register that the diodes are currently switched to the on position. Analog circuitry would instead react to how much electricity was passing through the diodes. Its possible to integrate analog and digital logic together in an electronic device.

Engineers classify all electronic components as either passive or active. Passive components wont introduce any net amount of electricity into the circuit that theyre wired to. As a result, passive components will never amplify signals running through a circuit. An active component can inject additional power into the circuit. Transistors and tunnel diodes are active components. Inductors, transformers, capacitors, and resistors are all passive components.

You only need a simple multimeter to measure any capacitor that you might not know the value of. Multimeters are driven by a transistor circuit, so you wont need to calibrate anything. Attach a fairly strong resistor to the terminals of the capacitor to discharge it before taking a measurement. This gets any excess voltage out of the capacitors electrolytes. Make sure theres no voltage running anywhere else in the circuit, and then attach the multimeter leads to the capacitor. Set it to measure in farads, and it will do the rest of the work for you. These meters are passive and wont damage other components if used properly.

There are four primary types of flux used when soldering metals together. The names for them are standardized by a document called J-STD-004, which is used by nearly all solder manufacturers to make sure theyre in compliance with good labeling practices. The four types of flux are as:

• Organic
• Inorganic
• Rosin
• Resin

If you want to be ready to replace components in any type of circuit, then you might want to start by having a large supply of resistors on hand. These are used in digital and analog electronics more than perhaps anything else. Youll also need several different categories of transistors. On top of that, youll probably find it useful to have some spares of the following items on hand:

• Varistors
• Thyristors
• Solenoids
• Potentiometers or Rheostats
• Transducers