Measuring a AC current with microcontroller

[bws]

measuring ac current circuit

hey

as topics say, how is the smartes way to do this ?? especially when its a uC who need the data ??

thx in advance

 

[engr_najam]

measuring a ac

i think it should be voltage across a fixed that will be proportional to current,

 

[dipnirvana]

how a/c current

That depends on ur requirement of the range,accuracy etc.

There are multiple way to do it, current transformer , Hall sensor or said above shunt resistor.

 

[dollar_124]

measuring ac current

I want to count the number of times the AC compressor runs in a day. I used a CT and output voltage is only 0.5volt.. I am a little confused how to give input to this AC voltage to the ADC input of ATMEGA8...

 

[smd_lover]

measure ac current coil

You can amplify this voltage ten times with a standard opamp amplifier circuit.
At Wiki you can see how that works.

 

[bws]

Re: Measuring a AC current

i have seen in a radio transmitter how they measure the output of the power when transmitting, to make sure of that the right effect is being transmitted, in the air.

this is done by laying a thin parralel line in the pcb-layout, right next to the output lane on pcb surface, this way there creates a voltage drop over the small line, a bit like a pot meter, and then the variable voltage drop could then be referenced to find out if the right effect was being transmitted. i believe that the principal behind this, has something to do whit magnetic influence of somekind, correct me if i am wrong please ??

so now is my qestion, if it also could be done whit a 50hz main voltage(230VAC) ??

or has can it only be done when working in the VHF(150-160Mhz was the radio working at) area ??

here is and example of my question

 

[FvM]

Measuring a AC current

You're apparently talking of a RF directional coupler. It's utilizing the coupling of transmission lines, not working at mains frequency (unless you have xx kilometer overland line).

A rogowski coil is a method to measure AC currents by induced magnetic fields without a core, but there's no way to have both, the primary conductor and the coil combined in a planar PCB design.

 

[Petre Petrov]

Re: Measuring a AC current

Hello!
I am not sure that the solution on your image is safe.
You must have a solution which is good for at least 1000V due to rare but dangerous pulses on 230V/50Hz.
There are rules for that Please follow the safety standards.
If you are planning to measure sinusoidal signals you probably could use:
https://www.ieindia.org/pdf/88/88ET104.pdf
I hope that is helpfull
BR