Understanding Voltage Divider Circuits

 The formula for the voltage divider

The voltage divider is a simple and commonly used circuit that allows you to divide a voltage into two parts. It is based on the principle that the voltage across a resistor is directly proportional to the resistance value. The voltage divider formula is given by:

Vout = (R2 / (R1 + R2)) * Vin

Where:

• Vout is the output voltage across the load resistor (R2)
• Vin is the input voltage
• R1 and R2 are the resistance values of the resistors in the circuit

The voltage divider is often used to reduce the magnitude of a voltage for use in a circuit or to create a reference voltage for use in a circuit. It is important to note that the voltage divider circuit will also draw current from the input voltage source, which can affect the operation of the circuit.

How to Use a Voltage Divider Circuit: 11 Steps

To use a voltage divider circuit, follow these steps:

1. Determine the input voltage (Vin) and the desired output voltage (Vout).
2. Calculate the resistance values needed for the resistors in the circuit using the voltage divider formula: Vout = (R2 / (R1 + R2)) * Vin.
3. Choose the resistor values based on the required resistance and the available resistor values. It is often best to use standard resistor values to make the calculation and selection process easier.
4. Connect the input voltage source to the circuit. The positive terminal of the voltage source should be connected to one end of resistor R1, and the negative terminal should be connected to one end of resistor R2.
5. Connect the other end of resistor R1 to the other end of resistor R2. This creates a voltage divider circuit.
6. Connect the load (the device or circuit that will be powered by the voltage divider) to the circuit. The positive terminal of the load should be connected to the other end of resistor R2, and the negative terminal should be connected to the negative terminal of the voltage source.
7. Measure the output voltage across the load using a multimeter. This will allow you to verify that the voltage divider is functioning properly and providing the desired output voltage.
8. If necessary, adjust the resistance values of the resistors in the circuit to fine-tune the output voltage.
9. Use the voltage divider to power the load as needed.
10. Disconnect the voltage divider circuit when it is no longer needed.
11. If you are using a potentiometer (variable resistor) in the voltage divider circuit, you can adjust the resistance of the potentiometer to fine-tune the output voltage as needed.

 

Use of voltage divider

Voltage dividers are used in a wide range of applications, including:

1. Reducing the magnitude of a voltage: Voltage dividers can be used to reduce the magnitude of a voltage for use in a circuit. For example, if you have a 12V power supply and need to use it to power a circuit that can only handle 5V, you can use a voltage divider to reduce the 12V to 5V.
2. Creating a reference voltage: Voltage dividers can be used to create a stable reference voltage for use in a circuit. For example, if you need a 5V reference voltage for a microcontroller, you can use a voltage divider to create a stable 5V reference.
3. Measuring voltage: Voltage dividers can be used to measure the voltage of a circuit. By measuring the voltage across one of the resistors in the voltage divider, you can calculate the voltage of the circuit.
4. Adjusting the gain of an amplifier: Voltage dividers can be used to adjust the gain of an amplifier by changing the resistance values of the resistors in the voltage divider.
5. Controlling the brightness of an LED: Voltage dividers can be used to control the brightness of an LED by changing the resistance values of the resistors in the voltage divider. This is often done using a potentiometer (variable resistor) in the voltage divider circuit, allowing the user to adjust the brightness of the LED.