A voltage divider circuit is a simple electronic circuit used to divide a voltage into smaller fractions or to obtain a specific voltage level from a larger voltage source. It consists of two or more resistors connected in series, and the output voltage is taken from the junction between these resistors. The ratio of the resistances determines the output voltage.
The basic principle behind a voltage divider is Ohm's law, which states that the voltage across a resistor is directly proportional to the current flowing through it. The voltage across each resistor is determined by the ratio of its resistance to the total resistance in the circuit.
Here's the general formula for calculating the output voltage (Vout) in a voltage divider circuit:
Vout = Vin * (R2 / (R1 + R2))
Where:
Vin is the input voltage applied to the voltage divider circuit.
R1 and R2 are the resistances of the two resistors in the circuit.
Construction of a voltage divider circuit:
Select the resistors: Determine the desired output voltage and the input voltage. Choose two resistors with appropriate resistance values. The ratio of the resistances should match the required voltage division ratio.
Calculate the resistance values: Use the formula mentioned above to calculate the resistance values for R1 and R2. Ensure that the resistors' power ratings are sufficient to handle the power dissipation, especially when dealing with high input voltages.
Connect the resistors in series: Connect one end of the first resistor (R1) to the positive terminal of the input voltage source (Vin). Connect the other end of R1 to one end of the second resistor (R2). Connect the remaining end of R2 to the negative terminal of the input voltage source (common ground).
Measure the output voltage: The output voltage (Vout) can be measured across the junction between R1 and R2.
Keep in mind that the output voltage will vary with changes in the load resistance connected to the output. If the load resistance is significant compared to R2, it may affect the voltage division ratio, and you might need to consider using an op-amp buffer to isolate the voltage divider from the load.
Voltage dividers have various applications in electronics, such as level shifting, sensor interfacing, and biasing components in circuits. They are essential building blocks in many electronic devices and systems.