1. What is the Current Calculation Formula?

The formula I = P / V calculates electrical current (in amps) from power (in watts) and voltage (in volts). This is particularly useful for determining the amp draw of a 25 watt VHF radio.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current in amps
• \( P \) — Power in watts
• \( V \) — Voltage in volts

Explanation: This formula is derived from Ohm's law and is fundamental in electrical calculations to determine current consumption.

3. Importance of Current Calculation

Details: Calculating current draw is essential for proper power supply sizing, circuit protection, and ensuring electrical systems operate within safe limits.

4. Using the Calculator

Tips: Enter power in watts and voltage in volts. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why calculate amp draw for a 25 watt radio?
A: Knowing the amp draw helps determine the appropriate power supply and wiring requirements for safe operation.

Q2: What is a typical voltage for VHF radios?
A: Most VHF radios operate at 12-13.8 volts DC, which is standard for mobile and marine applications.

Q3: How accurate is this calculation?
A: The calculation provides theoretical current draw. Actual draw may vary slightly due to efficiency factors and operating conditions.

Q4: Can this calculator be used for other devices?
A: Yes, the I = P / V formula applies to any DC electrical device when you know the power consumption and operating voltage.

Q5: What if my device uses AC power?
A: For AC circuits, power factor must be considered. The simple I = P / V formula works best for DC circuits or resistive AC loads.