Is there a way to unobtrusively make power measurements of a circuit if all you know if the current going through it? We have a Rogowski coil set up to measure the current of this circuit and now we need to be able to unobtrusively measure either the voltage or power going through the circuit, which already has a sheathe on the wires. Does anybody have ideas?
Unobtrusive voltage/power measurement of wire
Mar 16, 2006
12 Replies
No.
You have to measure the instantaneous voltage, the instantaneous current, multiply the two, sum or integrate the products, and then average the result.
Many new Rogowski compatible chips are being offered. Analog Devices and others.
Many thanks,
Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: don@tinaja.com
Please visit my GURU\'s LAIR web site at http://www.tinaja.com
Follow the wires to their source - measure there? Get the circuit schematic and figure out what it's response to the measured current should be?
Unobtrusive.........why?
RL
Part of our senior project describes measuring a system unobtrusively. Thanks for the help you guys :)
Are you sure the word is not "unintrusively"? Whole different meaning.
Seems a bit pedantic, but yes you are correct. Unintrusive would more accurately reflect how we are approaching this conundrum. Thanks.
Non-intrusively?
Best regards, Spehro Pefhany
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If the difference were subtle, I wouldn't have mentioned it, but unintrusive is like keeping it in your pants, while unobtrusive is like being invisible. Now you have me thinking about invisible intrusion. If I end up in Hell, its your fault. ;-)
Make sure you measure both the E field and the H field of the conundrum. Coordinate transformations can sometimes ease this task.
Many thanks,
Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: don@tinaja.com
Please visit my GURU\'s LAIR web site at http://www.tinaja.com
The assignment was probably not to have to break the main wire to insert a current sensor.
Many thanks,
Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: don@tinaja.com
Please visit my GURU\'s LAIR web site at http://www.tinaja.com
..and that as we know, is not a problem.
Thermal measurements will show power dissipation and give a rough idea of the input power,
- if the current waveform is known on input,
- if it's not a through-wire arrangement.
- if there's no other intended energy (RF, light or signal) being emitted.
RL
... unless the OP asks for something different, like (wait for it) . . . . . . . . . . . . . . unobtrusive.
Ed
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