Resistor Calculator To Reduce Voltage

Voltage Divider Equation:

\[ V_{out} = V_{in} \times \left( \frac{R2}{R1 + R2} \right) \]

Output Voltage (Vout):

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1. What is a Voltage Divider?

A voltage divider is a simple circuit that turns a large voltage into a smaller one. Using just two resistors in series, the output voltage is a fraction of the input voltage.

2. How Does the Calculator Work?

The calculator uses the voltage divider equation:

\[ V_{out} = V_{in} \times \left( \frac{R2}{R1 + R2} \right) \]

Where:

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

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

3. Importance of Voltage Division

Details: Voltage dividers are fundamental in electronics for creating reference voltages, level shifting, and sensor interfacing.

4. Using the Calculator

Tips: Enter input voltage in volts and both resistor values in ohms. 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 (Vout = Vin/2).

Q2: How do I choose resistor values?
A: Select values that won't draw excessive current but are small enough to not be affected by load current.

Q3: Can I use this for high power applications?
A: No, voltage dividers are inefficient for high power as they constantly dissipate power.

Q4: What about load resistance?
A: This calculator assumes no load. For accurate results with load, the parallel combination of R2 and load must be considered.

Q5: What's the maximum current through the divider?
A: I = Vin/(R1 + R2). Ensure resistors can handle this power (P = I²R).