how can i design an ac current meter circuit (like clamp meter)?

[syafiq hashim]

my question is how about to design an ac current meter/analyzer?
it is as what an clamp meter is about…i want to analyze the current in the DB and the data receive will be deliver into microcontroller..

i’m new and dont know much about this topic

 

[wkrug]

For such solutions it give Hall Generators or integreated Current sensors.
E.G. Honeywell and Allegro ( https://www.allegromicro.com/ ) produce such things.

What frequency should your part take for maximum?

For a dB Scale you can calculate with a Microcontroller, or you use a integrated dB to voltage converter like AD 636 J. Or a chip that has a integrated dB Scale and a digital Output like SPI or I²C.

Hall Current Sensors also can detect DC, so you should think about to implement such a measure function too.

 

[Sceadwian]

https://en.wikipedia.org/wiki/Current_clamp

 

[Reloadron]

You also have on the same topic. Starting multiple threads is not a good idea as it leads to confusion for those who want to help you. Hopefully a moderator will merge things.

As to the project it would go better if you fully explain what you want to do as in current and voltage ranges you want to measure. The more details the better.

Ron


Merged:Moderation:E

Thank You "E" I love organization. R

 

[Sceadwian]

Reloadron... The link you posted was to THIS thread..

Oh wait, nevermind just noticed the Merged note at the end of your post.

 

[BrownOut]

One simple way to build a noncontact current meter would be to wrap magnetic wire around a torroid core, and slide it over the wire you want to measure. Terminate the ends of the magnetic wire with a resistor connected between them. Calibrate the probe by using it to measure a known current.

 

[ljcox]

The Australian electronics magazine - Silicon Chip described a Clamp Meter in their September 2003 issue.

Altronics were selling the kit for it. I don't know if they still are.

See www.altronics.com.au and search for catalogue number K 2582

or send an email to kits@altronics.com.au

 

[syafiq hashim]

actually i would like to design an current detector that will detect/measure the ampere and send the data(measure result) to the PIC as an i/p.
the current meter will be connect directly to the power distribution board. specifically for single phase building (240V, 50Hz~60Hz,≤60A).

 

[Reloadron]

OK, then rather than the use of a clamp on design consider using a Current Transformer of the doughnut design type. Later when I am home I can post a few images of several. Maybe something like a 60:5 amp ratio size. Guessing you also want the voltage or just current?

Ron

 

[syafiq hashim]

can the measured data be an input for PIC microcontroller?
let say it sense 20A, can it send the data(20A) to PIC.

 

[BrownOut]

It can if the PIC has an A/D converter.

 

[syafiq hashim]

so what are suggesting for me to do? which type of circuit that i should design.
it would be my pleasure if you can help me out.

 

[BrownOut]

I suggest you use a current transformer, either buy one that Ron will provide details for later, or make one as I suggested in post #6. Get a PIC that has an integrated A/C converter and connect up the current transformer. We have PIC specialists here that can help you with the details.

 

[Reloadron]

OK, home from work so I can get to my pictures.

I suggest you think of things this way. You will need a current sensor to sense (measure) the AC mains current. There are several you can use with the CT (Current Transformer) among the more popular for an application like this. Attached are a few CT images to give you an idea of what a CT is.

The current carrying conductor forms the primary of the transformer and is passed through the center of a round iron core, the windings seen in the second image form the transformer secondary and provide a current output proportional to the primary current.

Now I strongly suggest you do a Google of Current Transformer Basics and read in detail links like this one to gain a good understanding of what they are and how they work. I suggest you read about and understand Burden Resistance as it is very important when using a CT.

You can buy one relatively inexpensive or as BrownOut suggest you can build your own. Building your own for a one time inexpensive project is a great way to learn.

There are other current sensing devices out there. I have included a picture of one such device which is a Hall Effect Current Sensor. These devices provide all the needed signal conditioning. While not cheap they do a very nice and accurate job. A unit like this one runs about $100 USD. The beauty is for a given current range they output a linear voltage of for example 0 to 5 volts making them ideal for analog inputs of micro-controllers and other analog to digital devices.

That should give you a start.

Ron