Re: gEDA-user: Transformer as voltage transducer?

[Steven Michalske <smichalske@xxxxxxxxx>]

On May 28, 2007, at 8:37 AM, Randall Nortman wrote:

> On Sun, May 27, 2007 at 11:16:18PM -0400, Steven Michalske wrote:
> [...]
>> as for voltage monitoring, I wouldn't worry much about using the
>> resistors.  put in a fast acting fuse at a reasonable low current.
>
> How do you suppose insurance companies feel about non-UL stuff on
> mains power?  Just in case I should happen to start a fire...
>

Fortunately, you don't have to monitor the voltage from the mains  
lines directly.

Run an appropriate wire from the fuse box to your device,  make it  
fused.   you can use a power entry module with a fuse if you like,   
just remember to fuse both hot lines.

You can monitor the voltage from say your range circuit. or other  
220V circuit.  the phase lag in measuring the voltage at another  
locations will be minimal.  Choose a braker at the top of the panel.   
1 foot is approx. 1 ns if I recall correctly in free space.  I leave  
the math to you for the amount of phase delay that corresponds to.   
You also have the inductance of the buss bar and main breaker.    
these should be negligible.

>> If you get the one that supports the di/dt Rogowski coil like the
>> ADE7753 then you won't have to disconnect the mains.  Some thing that
>> the electrician probably won't do with out pulling the meter.
>
> Yeah, I was looking at the Rogowski coil option, but I can't find
> anywhere to buy the things.  Do anybody know of a supplier?
>

http://homepage.ntlworld.com/rocoil/flexible.htm
Seems to make them,  you'll have to email them.

I googled and saw some others.

Also you can get a open core current transducer,  Digi-Key and Mouser  
cary some.

Steve.
>
> _______________________________________________
> geda-user mailing list
> geda-user@xxxxxxxxxxxxxx
> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user



_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user