EP 02 - Le pont diviseur de tension

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Published on Oct 29, 2024 This response is partially generated with the help of AI. It may contain inaccuracies.

Introduction

This tutorial explores the concept and application of voltage dividers, a fundamental electronic circuit used to reduce voltage levels. Understanding voltage dividers is essential for various electronic projects, as they help manage voltage levels to suit different components.

Step 1: Understanding the Basic Voltage Divider

  • A voltage divider is a simple circuit used to produce a voltage output that is a fraction of its input voltage.
  • It typically consists of two resistors connected in series.
  • The output voltage (Vout) is taken from the junction between the two resistors.

Practical Example

  • If you have two resistors R1 and R2 connected in series to a voltage source (Vin), the output voltage can be calculated using the formula:

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

Step 2: Analyzing the Open Circuit Voltage Divider

  • In an open circuit configuration, there is no load connected to the output.
  • The output voltage can be measured directly using a multimeter.
  • Ensure that the resistors are of suitable values to achieve the desired voltage reduction without drawing too much current.

Step 3: Modifying Current in the Divider

  • Adding a load to the voltage divider will change the output voltage due to the load's resistance.
  • The load can alter the current flowing through the resistors, impacting the overall voltage division.

Key Considerations

  • When calculating output voltage with a load, consider the load resistance (Rl) in parallel with R2:

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

Step 4: Creating a Variable Voltage Divider

  • A variable voltage divider can be made using a potentiometer instead of a fixed resistor.
  • This allows for adjustable output voltage.

Setting Up the Potentiometer

  • Connect the potentiometer between Vin and ground, with the wiper connected to Vout.
  • Adjust the potentiometer to vary the output voltage as needed.

Step 5: Implementing a Loaded Voltage Divider

  • When connecting a load, ensure that the voltage divider can supply the required current without significant voltage drop.
  • The voltage divider should be designed to handle the load's power requirements.

Example Calculation

  • If a load of 1kΩ is connected to the output of a voltage divider with R1 = 2kΩ and R2 = 1kΩ, recalculate Vout:

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

Conclusion

In this tutorial, we covered the fundamentals of voltage dividers, including their basic operation, how to modify current with loads, and how to create variable voltage dividers. Mastering these concepts is crucial for effective circuit design and component management in electronics.

Next steps could include experimenting with different resistor values, building actual circuits, or exploring more advanced applications of voltage dividers in electronic devices.