Voltage Divider Calculator for 3 Resistors

Voltage Divider Formula (3 Resistors):

\[ V_{out} = V_{in} \times \frac{R3}{R1 + R2 + R3} \]

Input Voltage (V_in):

volts

Resistor 1 (R1):

ohms

Resistor 2 (R2):

ohms

Resistor 3 (R3):

ohms

Output Voltage (V_out): volts

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1. What is a Voltage Divider Calculator for 3 Resistors?

Definition: This calculator determines the output voltage from a voltage divider circuit with three resistors in series.

Purpose: It helps electronics engineers and hobbyists design voltage divider circuits for various applications like sensor interfaces, reference voltages, and signal attenuation.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V_{out} = V_{in} \times \frac{R3}{R1 + R2 + R3} \]

Where:

\( V_{out} \) — Output voltage (volts)
\( V_{in} \) — Input voltage (volts)
\( R1, R2, R3 \) — Resistor values (ohms)

Explanation: The output voltage is proportional to the ratio of the bottom resistor (R3) to the total resistance in the divider chain.

3. Importance of Voltage Divider Calculation

Details: Accurate voltage division is crucial for creating reference voltages, interfacing different voltage level circuits, and protecting sensitive components from excessive voltages.

4. Using the Calculator

Tips: Enter the input voltage and all three resistor values. R1 and R2 can be zero (for simpler dividers), but R3 must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What if I only have two resistors?
A: Set R2 to 0 ohms, and the calculator will work for a standard two-resistor voltage divider.

Q2: Does this account for load resistance?
A: No, this calculates the unloaded output voltage. For loaded dividers, the load resistance becomes parallel to R3.

Q3: What's the maximum current through the resistors?
A: Current = V_in / (R1 + R2 + R3). Ensure resistors can handle this power (P = I²R).

Q4: Can R1 or R2 be zero?
A: Yes, but R3 cannot be zero as it would create a short circuit.

Q5: How precise are the results?
A: The calculation is mathematically exact, but real-world results depend on resistor tolerance and other factors.