Passive Devices

We’ve talked a lot here about PCBs.  But how important are they to electronics?  What other parts contribute to seamless way our electronic devices work and coordinate with each other?

PCB traces are metal wires connected between components.  The PCB material, on which the components and traces are placed, is made of insulator material), typically fiberglass with resin. This dielectric material can be of various kinds depending on the application of the circuit board.

Over the last few decades electronics technologies and product development have grown and rapidly have become more and more complex. Knowledge of electronic components is essential to build successful electronic products.

What other types of components go on a PCB?  One common type is passive devices .A passive device does not require energy to operate with the exception of an available alternate current circuit that its connected to.

Passive devices

This includes devices such as resistors, capacitors, inductors and crystals.

  • The resistor is a passive electrical component used to create resistance in the flow of electric current. In almost all electrical networks and electronic circuits they can be found. The resistance is measured in ohms.
  • capacitor (originally known as a condenser in the UK or cap for short) is a passive two-terminal electrical component used to store energy electrostatically in an electric field.
    • Examples of these are:
      • Surface mount capacitors
      • Multilayer Ceramic Capacitors
      • Cylindrical Capacitors
      • Three terminal capacitors
      • Wire-ended electrolytic capacitors
    • An inductor is a passive electronic component which is capable of storing electrical energy in the form of magnetic energy. It essentially uses a conductor that is wound into a coil. The inductor will induce a magnetic field in itself or in a core. It is conventionally said that it flows from south to north.
      • Examples of these are:
        • Iron Cored inductors
        • Variable inductors
        • Radio Frequency inductors
    • A quartz crystal wafer made from silicon is tightly fitted and controlled between two parallel metalized surfaces which make an electrical connection. It is used in oscillator circuit to provide a clock input to the processor device and is often a source of refence signals for radio frequency.
      • Crystals can be selected for the following:
        • Load capacitance
        • Fundamental frequency
        • Frequency tolerance
        • Frequency stability
        • ESR
        • Operating voltage

Next time, we’ll talk about active devices.

We know these parts are all critical to your build and lately we know they are harder and harder to find.  Reach out to us here at Spectrum Components and we can help you out.

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