A voltage divider circuit is a simple electronic circuit used to divide a voltage into smaller values. It consists of two or more resistors connected in series, and the output voltage is taken from the junction between these resistors. The basic principle behind a voltage divider is that the voltage drop across each resistor is proportional to its resistance, resulting in a proportionally reduced output voltage.
Here's how a voltage divider circuit is designed:
Determine the required output voltage (Vout): Decide the voltage you want to achieve at the output of the voltage divider circuit.
Identify the input voltage (Vin): Know the voltage that needs to be divided. This can be the voltage from a power supply or any other source.
Choose the resistor values: To calculate the resistor values needed for the voltage divider, you can use the following formula:
Vout = Vin * (R2 / (R1 + R2))
where:
Vout is the desired output voltage.
Vin is the input voltage.
R1 and R2 are the resistances of the two resistors used in the circuit.
Select a practical resistor value: Standard resistor values are commonly available, so choose the closest standard resistor values for R1 and R2 that are higher than the calculated values from the formula. This will give you a slightly lower output voltage, but it will be close enough for most practical applications.
Assemble the circuit: Connect the resistors in series, making sure to maintain the correct order (R1 followed by R2) and connect the input voltage (Vin) across the whole series. The output voltage (Vout) is taken from the junction between R1 and R2.
It's essential to keep in mind that the voltage divider circuit has some limitations. The output voltage is affected by the current drawn from it, and it can be sensitive to load changes. If the load impedance is low, it can significantly affect the output voltage. For more precise voltage division or lower sensitivity to load changes, other voltage regulation methods like voltage regulators or op-amp-based buffer circuits may be more suitable.