What is the formula for the average current?

Calculating the Average Current

In AC circuits, the current varies sinusoidally with time, creating a waveform. The average current over a complete cycle is a significant parameter that represents the net flow of charge.

Formula for Average Current

The average current over a complete cycle can be calculated using the following formula:

I_avg = 0.636 * I_peak

where:

• I_avg is the average current
• I_peak is the peak current

Explanation

The value 0.636 is the form factor for a sinusoidal waveform, which accounts for the fluctuating nature of the current. It is derived from the following expression:

Form factor = RMS current / Average current

For a sinusoidal waveform, the form factor is equal to 1.11, and the RMS current is equal to 0.707 times the peak current. Substituting these values into the above expression gives:

0.707 / I_avg = 1.11

Solving for I_avg, we get:

I_avg = 0.707 / 1.11 = 0.636 * I_peak

Application

The average current formula is commonly used in AC circuit analysis, particularly in power calculations. It provides a measure of the net power consumption or generation in the circuit. By multiplying the average current by the voltage, we can obtain the average power.