Basic Symbols

• The most basic components are resistors, capacitors and inductors. Other basic symbols include voltage sources and measurement devices.
  
  

Resistors

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  Resistors are components made from conductors or semiconductors such as tightly wound metal wires or carbon. They are used as current limiters and voltage dividers or reducers. Regular ones are usually represented by a series of triangles that are open at the bottom. Variable ones have an arrow drawn through the triangles.
  
  

Capacitors

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  Capacitors are composed from two parallel conductors, called plates. These plates are separated by a dielectric such as glass, air or paper. They have the ability to store a charge. This ability allows them to perform functions such as smoothing voltage spikes that are caused by lightning or by electrical switches opening and closing. Ordinary capacitors are symbolized by two parallel lines.
  
  

Inductors

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  Inductors are made from coils of wire, and are used to produce magnetic fields. They may have many coils, be placed in casings, or are just single bare coils on circuit boards. They are an essential part of devices such as tuners, transformers and motors. A solenoid, which is a wire in the form of a helix, is an example of an inductor. Inductors are symbolized by a series of coils.
  
  

Voltage Sources

• Credit: Jleedev
  
  Voltage sources may be batteries or alternating currents such as those drawn from an electrical outlet. Long and short parallel lines usually represent batteries. AC sources are usually circles with swirls inside.
  
  

Multimeters

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  Multimeters measure the strength of signals in a circuit. When placed on a voltmeter setting, it measures the amount of AC or DC voltage in a circuit. When operating as an ammeter, it measures the strength of current. A circle with a V inside represents a voltmeter, while a circle with an A inside represents an ammeter.
  
  

Miscellaneous

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  The symbol for ground is usually a group of several short parallel lines.
  
  Switches are represented by a line with a piece that is held at an angle to the rest of the line. They are used to stop and start the flow of current in a circuit.
  
  Tip: Once you become comfortable recognizing the most common elements of a circuit, you may proceed to learn the symbols of the most common semiconductor components. These include the diode, transistor and op-amp.