Aboutcleggsan Expertise All technical areas of Electronics Engineering.
Experience BSEE, MBA, Design, R&D, University Research.
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Organizations IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.
Expert: cleggsan Date: 6/18/2008 Subject: high amps low voltage
Question I am conducting a test an 262 mcm and 535 mcm wire to be used in a windmill set up. Part of my test is to heat the wire to 90c. I'm figuring 500-700 amps are going to be needed to do this. Do you have any suggestions on how or what I can use to create this many amps preferably low voltage, dc will also work for me.
Answer Use a table or tables such as are found at:
and determine the resistance per foot and the temperature rise needed and the current requirement to do so. It will likely require you to do some experimental testing with a variable current supply in order to get the right temperature. In a sophisticated system where the wire temperature must be kept within a range you would need an automatically adjustable supply with a connection to a thermocouple that is attached to the wire for temperature monitoring.
You could use a ac supply or dc supply and depending on the distance of the wire and the resulting terminal voltage requirement you would select from a constant voltage or constant current supply. For a short run of wires the voltage would be very low and a constant current supply would be the better choice. If the wire runs are long and the voltage over a few volts a conventional supply would do the job.
Remember, from Ohm's Law: Voltage = Current times Resistance. Power = Voltage times Current. Just as an example, if a wire you are heating required 10 amps and the resistance was .1 ohm/ft and the run was 10 feet you would have a total resistance of 10 ohms and the current of 10 amps would produce a voltage requirement of 10 v and the power consumption would be 10v times 10 amps or 100 watts (the heat of a 100w light bulb for comparison).
This Agilent supply is capable of being set for either constant voltage or constant current - up to 10 amps.
Now, if you need much more power (and current) you would need to step up the wattage OR break your heated wire into sections and power them section by section.
If you really need up to 700 amps it will be a significant cost and size. Depending on how long the wire runs are you could be talking wattage requirements in the KW region.
So, if this is sufficient, good luck. If not, let me know more and we can to to the next level of discussion.
