1. What is a Current Limiter Resistor?

A current limiter resistor is used to restrict the amount of current flowing through a circuit. It protects components from excessive current that could cause damage or failure.

2. How Does the Calculator Work?

The calculator uses Ohm's Law to determine the appropriate resistor value:

Where:

• \( R \) — Resistance in ohms (Ω)
• \( V \) — Voltage across the resistor (volts)
• \( I_{max} \) — Maximum desired current (amps)

Explanation: The resistor value is calculated by dividing the voltage by the maximum current you want to allow in the circuit.

3. Importance of Current Limiting

Details: Current limiting is essential for protecting sensitive components like LEDs, transistors, and integrated circuits from damage due to excessive current flow.

4. Using the Calculator

Tips: Enter the voltage across the resistor and the maximum current you want to allow in the circuit. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What happens if I choose a resistor with lower value than calculated?
A: The current will be higher than your maximum limit, which may damage components.

Q2: Can I use this for LED current limiting?
A: Yes, this is commonly used for LED circuits, but remember to subtract the LED's forward voltage from your supply voltage first.

Q3: How do I account for power dissipation?
A: Calculate power using P = I²R and ensure your resistor's wattage rating is higher than this value.

Q4: What if my calculated resistor value isn't standard?
A: Use the next higher standard resistor value to ensure current stays below your maximum limit.

Q5: Does this work for AC circuits?
A: For AC, you need to consider impedance rather than just resistance, unless dealing with purely resistive loads.