[SOLVED] Measuring high voltage and high currents ..

[chacmool]

Hello,

I would like to construct a power line monitor. So, i need to measure high voltage and high currents in order to be treated by a microcontroller. What kind of sensor do i use for that?? what about the signal conditioning between the sensors and the A/D converters? ...
any hint will be gratefully ..

chak-mool


Does anyone has a circuit to

 

[bastos4321]

Hi,

What do you mean for high voltage ...

If it is to the power line (240v), you can use a meter tranformer to get the voltage and a hall sensor to probe the current. Usualy the hall sensor can deal with about 100A.

regards bastos

 

[chacmool]

Hi,

I'm trying to monitor around 400A@450Vca ..

the sensor i've seen for currents give me a signal 0-5A .. so, a question : does anybody know a circuit to conditioning this signal in on order to put it to the A/D converter?? ..

2nd. what about the voltage measurements ?? what to use for that?

thanks,

chak-mool

 

[Alexg]

Take a look at cyrrus logic, Texas instruments at the Mps430 section and Analog devices. They have power measurement chips and very nice application notes available.

Best regards,
Alexg

 

[backdoor_]

The easiest way of doing this is using a CT and a PT.
CT>
http://www.magnelab.thomasregister.com/olc/magnelab/modelsof.htm#SCT-1250s

PT>
http://www.magnelab.thomasregister.com/olc/magnelab/potentia.htm

Both outputs have been converted to low voltage, all you have to do is level-shifting.


backdoor_

 

[Alexg]

On 2001-10-13 06:52, backdoor_ wrote:
The easiest way of doing this is using a CT and a PT.
Both outputs have been converted to low voltage, all you have to do is level-shifting.

Converting to RMS for measuring can also be very processing intensive. If you need RMS power look at the chips to do it in hardware.

Best regards,
Alexg