What is voltage?

Voltage definition

    Voltage is a physical quantity that measures the energy difference generated by the unit charge in the electrostatic field due to the different potential, voltage is the reason for the directional movement of free charges in the circuit to form the current, the international system of units of voltage is volts (V, referred to as volts).

Voltage direction

     From high potential to low potential.

Voltage calculation

    The charge moves from point A to point B in the electric field, and the ratio of the work done by the electric field force to the amount of charge is called the potential difference between two points AB (the difference of potential between two points AB, also known as the potential difference), which is expressed by the formula:

    Where, for the work done by the electric field force, q is the amount of charge.

Voltage law

1. Voltage series parallel relationship

   
   

    If the components in a circuit contain only a series or parallel relationship, and are directly connected to the power supply, regardless of the internal resistance of the power supply, then the total voltage at both ends of the series circuit is equal to the sum of the voltages at both ends of each part of the circuit. The voltage at both ends of each branch of the parallel circuit is equal to and equal to the power supply voltage. 

   

2. Kirchhoff's voltage law

   
   

   The algebraic sum of the voltage drop along any loop at any time in a lumped parameter circuit is zero. 

Voltage classification

1. High voltage : Based on the voltage to the ground of the electrical equipment, the high voltage is when the voltage to the ground is higher than or equal to 1000 volts.

2. Low voltage : When the voltage to the ground is less than 1000 volts, the voltage is low.

3. Safety voltage : Refers to the human body for a long time contact without the risk of electric shock voltage.

Measurement method

 Potentiometer is one of the main instruments used to directly and precisely measure electromotive force or potential difference in electromagnetics.Potentiometer A precision instrument that uses the compensation principle to accurately measure electromotive force or potential difference. It has simple structure, strong intuitiveness and good stability.

 Potentiometer