A voltage divider circuit is a basic electronic circuit used to divide a voltage into smaller fractions. It consists of two or more resistors connected in series across a voltage source. The purpose of this circuit is to obtain a specific voltage level that is a fraction of the input voltage.
The voltage across each resistor in a series circuit is proportional to the ratio of its resistance value to the total resistance of the circuit. The voltage divider equation can be used to calculate the output voltage in such a circuit:
Vout = Vin * (R2 / (R1 + R2))
Where:
Vout is the output voltage across the second resistor (R2).
Vin is the input voltage across the entire voltage divider circuit.
R1 is the resistance value of the first resistor.
R2 is the resistance value of the second resistor.
To construct a voltage divider circuit, follow these steps:
Select Resistors: Choose two resistors with the desired resistance values. The ratio of these resistors will determine the voltage division ratio.
Calculate Ratio: Calculate the ratio of R2 to the sum of R1 and R2. This ratio will determine how the input voltage is divided.
Connect in Series: Connect the two resistors in series. This means connecting the end of one resistor to the start of the other resistor.
Connect to Voltage Source: Connect the input voltage (Vin) to the junction between the two resistors. This junction will be your output point (Vout).
Measure Output: The voltage at the output point (Vout) will be the voltage division of the input voltage based on the resistor values and the formula mentioned earlier.
Keep in mind that the values of the resistors and the desired output voltage fraction are key factors to consider. Additionally, the choice of resistor values must also take into account the current flowing through the circuit, as larger resistors can lead to smaller currents and potential stability issues.
Voltage dividers are commonly used in various applications, such as in sensor interfacing, level shifting, biasing circuits, and analog-to-digital converter input scaling. It's important to note that while voltage dividers are simple and versatile, they can be affected by load impedance and can introduce signal attenuation, so careful consideration is needed for certain precision applications.