Wat is Volt?

What is Volt?

For those less familiar with electrical terms like voltage, current, and resistance, we have written several articles on the subject.

Electric voltage, expressed in Volts (V), is the difference in electrical potential between two points in an electrical circuit. You can compare voltage to the pressure in a water pipe: the higher the pressure, the stronger the water flows. The same principle applies to electricity – the higher the voltage, the greater the "urge" for electrons to flow.

Alessandro Volta

The unit: Volt

The unit Volt is named after the Italian physicist Alessandro Volta, who invented the first electric battery, the 'Voltaic Pile'. One Volt is defined as the potential difference that drives one Ampere of current through a resistance of one Ohm (V = I × R).

Voltaic Pile

Common Voltage Levels

In practice, you will encounter various voltage levels:

  • Low voltage (< 50V): Batteries (1.5V, 9V, 12V), USB (5V), LED lighting (12V/24V)
  • Mains voltage (230V): Standard household voltage in the Netherlands and Europe
  • Three-phase voltage (400V): For heavier equipment and industrial applications
  • High voltage (> 1000V): Power grids, transformers, industrial installations

Voltage Levels

How does voltage work?

Voltage arises from a difference in electrical charge. In a battery, chemical reactions cause an excess of electrons at the negative terminal and a deficit at the positive terminal. This difference creates an "electrical pressure" that pushes electrons through a circuit once a conductor is connected.

Measuring voltage?

You measure voltage with a voltmeter or multimeter, always in parallel with the component to be measured:

  1. Set the multimeter to the correct voltage setting (AC or DC)
  2. Place the red probe on the positive measurement point
  3. Place the black probe on the negative measurement point or ground
  4. Read the value

Alternating Current (AC) vs. Direct Current (DC)

  • Direct Current (DC): Constant voltage in one direction, such as with batteries. Symbol: ⎓
  • Alternating Current (AC): Voltage that periodically changes direction, such as mains voltage (50Hz in Europe). Symbol: ~

Voltage in Ohm's Law

Voltage is one of the three quantities in Ohm's Law:

V = I × R

  • V = Voltage in Volts
  • I = Current in Amperes
  • R = Resistance in Ohms

With this, you calculate:

  • The required voltage: V = I × R
  • The current at a given voltage: I = V ÷ R
  • The resistance: R = V ÷ I

Practical Applications

1. Device Selection

Always check that the voltage of a device matches your mains voltage. A 110V device on 230V will be damaged.

2. Voltage Drop

In long cables, voltage drops due to resistance. With a 5% voltage drop on 230V, 218.5V remains – which is too little for some devices.

3. Transformers

Convert high voltage to low voltage (or vice versa) for safe use or efficient transport, for example.

4. Battery Capacity

The voltage of a battery decreases as it discharges. A full 12V battery initially has 12.6V, an empty battery often 10.5V or less.

Voltage Sources

Various sources provide voltage:

  • Batteries and accumulators: Chemical energy → electrical voltage
  • Dynamos and generators: Mechanical energy → electrical voltage
  • Solar panels: Light energy → electrical voltage
  • Power supplies: Convert mains voltage to desired voltage

Conclusion

Electrical voltage (Volt) is the driving force behind electric current. Understanding voltage is important for hazardous situations involving electricity, sizing installations, and complying with NEN 3140 and NEN 1010 standards. Whether you are building a simple LED installation or designing complex industrial systems.

 

Back to blog