Electrical components are parts you use in electronics projects. Simple enough,right? You use some electrical components to control the flow of electricity, such as a dimmer switch that adjusts the brightness of a light. Electricity simply powers other electrical components, such as speakers blasting out sound. Still other electronic components, called sensors, detect something (such as light or heat) and then generate a current to do something in response, such as set off an alarm.
In this section, you meet some basic electrical components. Next Chapters provide much more detail about components.
Electrical components, or parts, can control electricity. For example, a switch connects a light bulb to electric current. To disconnect the light bulb and make it go dark, the switch simply makes a break in the circuit.
Some other parts that control electricity are resistors, capacitors, diodes, and transistors. You can find more information on these parts in next Chapter.
Controlling electricity even better (ICs)
Integrated circuits, or ICs, are components that contain a whole bunch of miniature components (such as resistors, transistors, or diodes, which you hear about in Chapter 4) in one device that may not be much bigger than an individual component. Because each IC contains many components, one little IC can do the same job as several individual parts.
An audio amplifier is one example of an IC. You can use audio amps to increase the power of an audio signal. For example, if you have a microphone, its small output signal is fed through an audio amplifier to make a strong enough signal to power a speaker.
Another type of IC used in electronics projects is a microcontroller, a type of integrated circuit that you can actually program to control cool gadgets like robots. We discuss micro controllers in more detail in Chapter 13.
Sensing with sensors
Certain electrical components generate a current when you expose them to light or sound. You can use the current generated, together with a few of the components listed in the previous sections that control electricity, to turn on or off electronic devices, such as light bulbs or speakers.
Motion detectors, light sensors, microphones, and temperature sensors all generate an electrical signal in response to a stimulus (motion, light, sound, or temperature, respectively). These signals can then be used to turn other things on or off. A high signal level might turn something on and a low signal level turn something off. For example, when a salesperson walks up to your house, a motion detector can turn on a light (or better yet, sound a general alarm).
These signals take different forms, depending on the component supplying them. For example, a microphone supplies an AC signal, and a temperature sensor supplies a DC signal.
Figure 1-1 shows diagrams of a few signals that you run into often when working with electronics. These signals include
_ + 5 Volt DC signal: A high input.
_ 0 volt DC signal: A low input.
_ 0 to 5 volt DC square wave: The output of an oscillator (a device that cycles between high and low voltage); if you use this signal as input to a light bulb, it causes the light to blink on and off.
_ - 5 volt to + 5 volt AC sine wave: A signal, such as from a microphone, that generates alternating current that a device, such as an amplifier, uses as input. A microphone generates the waveform in Figure 1-1 when
it receives the sound produced by a tuning fork. Notice in Figure 1-1 that the transitions from +5 volts to -5 volts are gradual for the sine wave and more abrupt in the square wave.
You can find out more about various types of sensors in Chapter 5.
Electricity can power electrical components to produce light, heat, sound,motion, and more. For example, an electric current supplied to a DC motor causes the shaft of the motor to rotate, along with anything you’ve attachedto that shaft.
You can power speakers, light bulbs, LEDs, and motors with electricity. If you want to read more about these types of components, check out Chapters 4 and 5.