Why use a Voltage divider? A Guide to Voltage Divider Applications

What is a Voltage divider?

A voltage divider is a simple electronic circuit that can be used to divide a voltage into smaller values. It consists of two resistors connected in series between a voltage source and ground, with the output voltage taken across one of the resistors.

There are several reasons why voltage dividers are used:

  1. Scaling voltage: One of the most common reasons for using a voltage divider is to scale down a voltage to a lower value that is appropriate for a particular application. For example, a sensor may output a voltage that is too high for a microcontroller input to handle, so a voltage divider can be used to reduce the voltage to a safe level.
  2. Biasing: Voltage dividers can be used to set the bias voltage for transistors or other electronic components. By adjusting the values of the resistors, the bias voltage can be set to a precise value that is required for the proper operation of the component.
  3. Reference voltage: A voltage divider can be used to create a stable reference voltage for use in other parts of a circuit. By choosing the values of the resistors carefully, a stable voltage can be created that is unaffected by changes in the input voltage or temperature.
  4. Impedance matching: In some cases, a voltage divider can be used to match the impedance of two different parts of a circuit. This can be important in order to ensure maximum power transfer between the two parts.

Overall, voltage dividers are a useful tool for creating specific voltages and for setting the bias or reference voltages in electronic circuits.

What is Voltage?

Voltage, also known as electric potential difference, is a measure of the energy required to move a unit charge from one point to another in an electrical circuit. In simpler terms, it is the force that pushes the electrons in a circuit. Voltage is measured in volts (V) and is represented by the symbol ‘V’.

The voltage in a circuit is created by a voltage source, such as a battery or a generator. When a voltage source is connected to a circuit, it causes the electrons to flow from the negative terminal of the source to the positive terminal. This flow of electrons is called current.

Understanding Voltage in Electrical Circuits

To understand voltage in electrical circuits, it is important to understand the basic components of a circuit. A circuit is made up of three essential components: a voltage source, a load, and conductors.

The voltage source is the component that provides the energy required to move the electrons through the circuit. The load is the component that consumes energy, such as a light bulb or a motor. Conductors are wires or other materials that connect the voltage source and the load.

The voltage in a circuit is measured between two points in the circuit. The difference in voltage between these two points is called the voltage drop. The voltage drop is the amount of energy that is consumed by the load as the current flows through it.

Voltage and Current Relationship

Voltage and current are closely related in an electrical circuit. The relationship between the two is described by Ohm’s law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points. This relationship can be represented by the equation I = V/R, where I is the current in the circuit, V is the voltage, and R is the resistance of the circuit.

Importance of Voltage in Electrical Engineering

Voltage is a crucial concept in electrical engineering because it plays a vital role in the functioning of electrical systems. It is used to power various devices and equipment, such as lights, motors, and computers.

In addition, understanding voltage is essential in designing and analyzing electrical systems. Engineers must ensure that the voltage is appropriate for the equipment and components in the circuit. Overvoltage can damage equipment, while undervoltage can cause it to malfunction.

What is a Voltage spike?

A voltage spike, also known as a power surge, is a sudden, brief increase in voltage in an electrical circuit. Voltage spikes can be caused by a variety of factors, such as lightning strikes, power outages, or the cycling on and off of large electrical loads.

Voltage spikes can cause damage to electronic devices, as they can exceed the maximum voltage rating of the device and cause components to fail or malfunction. In some cases, voltage spikes can even cause permanent damage to the device.

To protect against voltage spikes, surge protectors are commonly used. Surge protectors are designed to detect voltage spikes and divert the excess voltage to the ground, protecting connected devices from damage. Some electronic devices, such as computers and televisions, also have built-in surge protection to help protect against voltage spikes.

Why does Voltage occur?

When a conductor, such as a wire, connects two points with different electric charges, electrons will flow from the point of higher charge to the point of lower charge, creating a current. The voltage is a measure of the potential energy that is available to move the electrons through the circuit, and it is proportional to the amount of work that can be done by the electric field on the charges.

Voltage can also be generated by various devices such as batteries, generators, and power supplies, which convert other forms of energy into electrical energy. In these cases, the voltage is created by a separation of charges, which creates an electric potential difference between two points.


Voltage is a fundamental concept in electrical engineering, and understanding its basics is crucial for anyone interested in this field. It is the force that pushes electrons through a circuit, and it is measured in volts. Voltage is closely related to current, and Ohm’s law describes their relationship. In addition, voltage is essential in designing and analyzing electrical systems, and engineers must ensure that the voltage is appropriate for the equipment and components in the circuit.

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