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An electrical circuit can be realised as a combination of various circuit elements connected via electrical wires so that the current passes through it. The components include a bulb, a resistor, a capacitor, an inductor, a transmitter, an ammeter, a voltmeter connected to a battery, and a switch. For every element in a circuit, there exist unique circuit symbols for them. The battery provides the necessary potential difference due to which current can flow through the wire, and electrical measurements can be taken on the circuit. The current in a circuit flows from the battery’s positive terminal to the negative terminal. 

 Circuit symbols 

 When we study circuits, we start with a circuit diagram, a pictorial representation of all the elements connected in the circuit and the direction of the current. However, the pictorial representation is facilitated by the use of circuit symbols. 

There is a set of symbols used to represent different elements in the circuit, and they help us picture the circuit diagram better. These symbols are accepted worldwide, thereby reducing any errors in the calculations. For example, in a power grid, there are many electrical components, so it is important to understand the meaning of circuit symbols and their usage accordingly. The symbols can be represented graphically and by assigning a letter or set of letters to any circuit element. Either way, this helps us understand the concept of electrical circuits and Circuit Symbols in a better way. 

 Essentiality of Circuit Symbols 

 Symbols are essential as they help shorten workload in industries while creating the blueprints of a machine. However, a circuit diagram is a compact representation of an actual circuit by smart use of symbols, numbers, and lines. It can be understood as a map for electronic circuits where each letter holds a unique meaning. 

For example, the symbol ‘R’ can be used for a resistor. Suppose a circuit resistor has a value of 2 ohms, then while making a circuit diagram, one can write R= 2Ω. Similarly, the letter assigned for a capacitor is ‘C’, and so for a circuit having a capacitor of 3 mF, we can write C=3mF on the circuit diagram for better representation. 

 Types of Circuit Symbol 

 The true meaning of circuit symbols can be understood in this section, as this is where we see what symbols/letters are assigned for various circuit elements.  

  1. Resistor – It is represented by the letter ‘R’. As resistance is known as the disruption in the path of the current, its symbol can also be represented as a line having a lot of curves. The line is the wire, and the curves are the obstruction in the current path.  
  1. Fuse – A fuse is fitted in all electrical circuits to present damage due to short-circuiting. It is represented by the letter ‘F’. 

 Diode – A diode is an element used in semiconductor circuits and is given the letter ‘D’.  

  1. Plug – A plug is like a switch in an electrical circuit assigned to the letter ‘P’. 
  1. Transistor – A circuit element formed by PN junction diode, and so the assigned letter is ‘Q’ or ‘TR’. 
  1. Power supply – It converts AC to DC in the circuit represented as ‘PS’.  
  1. Inductor – It is used to store energy from the magnetic field and is assigned the letter ‘L’. 
  1. Capacitor – It is used to store electrical energy and is represented as ‘C’. 
  1. Batter – It is represented by the symbol ‘BT’ in an electrical circuit. 
  1. Loudspeaker – The symbol ‘LS’ is used for circuits containing the speaker.   
  1. Attenuator – These are especially used in optical fibre communication and are represented as ‘ATT’. 
  1. Bridge rectifier – All AC circuits contain rectifiers for AC to DC conversion and are assigned the letter ‘BR’. 
  1. Transformer – An element that converts electrical energy from one AC form to another circuit and is represented as ‘T’. 
  1. Switch – It is used to either connect or disconnect the current flow in a circuit and is represented as ‘S’. 
  1. Transducer – It is represented by ‘X’ and is used to transform one form of energy to another.  

Conclusion

 Electrical circuit diagrams consist of special symbols and representations known as Circuit Symbols that help better visualise a circuit. Each circuit element has its own symbol to avoid confusion and is widely accepted in industries. 

The necessity of such symbols is to reduce the complexity of circuit diagrams by using symbols, numbers, and lines for better understanding. The Circuit Symbols depict how each element/component look in the circuit elements. Upon reading the text, the reader shall be able to get the hang of such symbols and prepare notes accordingly.