Resistor Voltage Divider Calculator

Voltage Divider Formula:

\[ V_{out} = V_{in} \times \frac{R2}{R1 + R2} \]

Output Voltage (V_out): volts

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1. What is a Resistor Voltage Divider?

Definition: A voltage divider is a simple circuit that turns a large voltage into a smaller one using two resistors.

Purpose: It's commonly used in electronics to create reference voltages, reduce signal levels, and interface between different voltage circuits.

2. How Does the Voltage Divider Work?

The calculator uses the formula:

\[ V_{out} = V_{in} \times \frac{R2}{R1 + R2} \]

Where:

\( V_{out} \) — Output voltage (volts)
\( V_{in} \) — Input voltage (volts)
\( R1 \) — First resistor value (ohms)
\( R2 \) — Second resistor value (ohms)

Explanation: The output voltage is proportional to the ratio of R2 to the total resistance (R1 + R2).

3. Importance of Voltage Dividers

Details: Voltage dividers are fundamental in circuit design, used in sensor interfaces, biasing transistors, and creating reference voltages.

4. Using the Calculator

Tips: Enter the input voltage and both resistor values. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What happens if R1 = R2?
A: The output voltage will be exactly half of the input voltage (V_out = V_in/2).

Q2: Can I use this for AC voltages?
A: Yes, but only if the frequency is low enough that the resistors' impedance isn't affected.

Q3: What's the maximum current through the divider?
A: I = V_in/(R1 + R2). Ensure resistors can handle this power (P = I²R).

Q4: Why does my actual output voltage differ?
A: Real-world factors like resistor tolerance, temperature effects, and load resistance can affect the output.

Q5: What if I need a specific output voltage?
A: Rearrange the formula to solve for R2: R2 = (V_out × R1)/(V_in - V_out).