# power factor meter using Arduino : How to measure power factor

How to design power factor using Arduino? How to measure power factor using Arduino Uno R3 ? In this project, I have designed a power factor meter using Arduino Uno R3.  In last two articles, I have posted project on how to measure alternating voltage using Arduino and how to measure alternating current using Arduino? As you know power factor is used to calculate ac power consumed by the load. It is also used to design energy meter. So by designing power factor meter we can design digital ac watt meter very easily. Because we know that ac power or watt consumed by the load is equal to product of ac voltage, ac current and power factor. we already seed how to measure ac voltage and ac current using Arduino and if we able to design power factor meter using Arduino, then we can easily design digital ac watt meter using Arduino.

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### Main components for power factor measurement using Arduino

Followings are the main components used in this project.

• Arduino : Arduino is a heart of this project. Arduino measured the time difference between current wave form and voltage wave forms. The time difference between current wave form and voltage wave form is basically a phase difference between two waves.  This phase difference is used to calculate power factor with the help cos function that is cos(phase difference).
• Current sensor:  I have used acs712 current sensor in this project. Output wave of current sensor is fed to Arduino analog channel. Current sensor can also use to measure current and to measure current wave form of load current.
• voltage sensor: In this project, I have used step down transformer to step down voltage from 220 volt AC to 12 Volt AC and further this voltage is step down using voltage divider circuit. Because Arduino can never measure voltage more than 5 volt directly.
• Lcd display: Lcd is interfaced with Arduino to display measured voltage on lcd. if you don’t know how to use LCD with Arduino, you can check this tutorial on lcd interfacing with Arduino.

So these are the main components used for power factor measurement using Arduino and how to design power factor meter using Arduino development board.  So now let’s check the circuit diagram of Arduino based power factor meter.  I have explained all the main components used to design arduino based power factor meter above.

### Circuit diagram Arduino based power factor meter design

Circuit diagram of Arduino based power factor meter is given below:

Circuit diagram of power factor meter using Arduino consists of current sensor and voltage sensor circuits. Current sensor circuit use acs712 current sensor and voltage sensor circuit consists of step down transformer and  voltage divider circuit.  Arduino measures the power factor by comparing the time difference between current wave form and voltage wave form.  After calculating power factor, Arduino displays it on LCD.  Video simulation of arduino based power factor meter is given below: