How to measure AC voltage using a microcontroller?

How to measure AC voltage using a microcontroller?

AC voltage measurement using digital millimeter AC voltage measurement using analog voltmeter AC voltage measurement using microcontroller AC voltage measurement using potential transformer and digital display (I will discuss this method in this tutorial) AC voltage measurement using difference amplifier and pic microcontroller

Why does PIC microcontroller not show high voltage?

In Above picture, resistor R1, R2, R3 R4, and R5 have high values which do not allow high voltage to appear across op-amp. Because high input resistors are used that’s why micro ampere current will low and this way power loss will be in mili watts.

Can a microcontroller read a negative voltage cycle?

Sine wave have zero DC voltage level and negative voltage cycle. Microcontroller can not read negative voltage.So we increase the DC level of sine wave by 5 volt.In this way negative voltage will not appear across microntroller. Now output peak voltage from op-amp is 5 + 2.8301 = 7.8301 volt.

How does a pull up resistor work on a microcontroller?

Putting a pull up resistor will set the input voltage near Vcc and it will read as a 1. A pull down resistor will bring the voltage near 0V, and it will read as a zero. Figure 5-2 shows pull up and pull down resistors. The switch, sensor, or other component that generates the normal 1 and 0 voltages must be able to over drive the resistor.

What should the voltage be on a capacitive voltage divider?

If one builds a capacitive voltage divider using two safety-rated 22pF caps in series on the line side, and a 0.001uF cap on the line side, the voltage on the output cap will be about 1/100 of the input voltage in the absence of any other loading.

How is a potential transformer used to measure AC voltage?

Followings are the main components of ac voltage measurement project. Brief descriptions of all components are also given below: Potential transformer is a type of transformer which is used to step down ac voltage. It is used to measure ac voltage by stepping down AC voltage.

What kind of display is used to measure AC voltage?

Liquid crystal display or LCD is used to used to display value of measured ac voltage. 16X2 LCD is used in this project. LCD is interfaced with pic16f877a microcontroller. IF you don’t know how to interface LCD with PIC16F877A microcontroller, check following article:

How to safely connect external devices to a microcontroller?

This article covers important drivers and proper circuitry required to safely connect external devices to an MCU’s I/O. As soon as you have an idea for a project, it is very tempting to jump right in and connect Arduinos and micro:bit devices to circuits and devices such as LEDs, relays, and speakers.

What happens when a microcontroller outputs a 0?

When the microcontroller (connected to “IN”), outputs a 1 then the transistor Q1 turns on. This turns on relay RL1 and the result is the lamp (R2), turning on. If the microcontroller outputs a 0 then the transistor Q1 turns off which disables the relay and therefore the lamp turns off.

How is a microcontroller connected to a transistor?

This simple circuit is handy for controlling high powered LEDs by microcontrollers where the microcontroller output is connected to “IN”. When the microcontroller outputs a 0 then the transistor Q1 turns off and so does the LED D1. When the microcontroller outputs a 1 then the transistor turns on and therefore D1 also turns on.

How is the resolution of a microcontroller defined?

Resolution of a microcontroller is define as minimum analog voltage a ADC can measure. For example if we have a 3 bit ADC and reference voltage is 5 volt. The minimum voltage it can measure is

What is the peak voltage of a PIC microcontroller?

Vout = .0091 * 311 = 2.8301 volt (peak output voltage) As you see above figure we have connected other terminal of R7 to 5 volt instead of ground as we do while using difference amplifier in many applications.

What is the peak voltage of a micrcontroller?

Because peak voltage is the maximum voltage input to micrcontroller analog pin.So with a .0091 gain, with respect to peak voltage of sine wave output voltage from op-amp is : Vout = .0091 * 311 = 2.8301 volt (peak output voltage)