Potential Transformer
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From: Kit Talich on 19 Jan 2006 14:43 Hello all! I am currently working on my senior design project of a Digital Power Meter here at the South Dakota School of Mines and Technology (Shamless plug!). I plan to measure and display Voltage, Current, Power and Power Factor. To do this I plan to sample both waveforms and calculate the rest. I have found a Hall Effect type current sensing chip. While I have found a few 120V-5V PT's my personal requirements are 230V 10A. Potential Transformers that accomplish this feat seem to be a little more rare. Does anyone out there know of somewhere I can find some of these? Small size would also be desired. P.S.: Gimme a JOB! B.S. EE minor:CSC
From: Ian Stirling on 19 Jan 2006 14:52 Kit Talich <Oxmmdox(a)gmail.com> wrote: > Hello all! > > I am currently working on my senior design project of a Digital > Power Meter here at the South Dakota School of Mines and Technology > (Shamless plug!). I plan to measure and display Voltage, Current, Power > and Power Factor. To do this I plan to sample both waveforms and > calculate the rest. I have found a Hall Effect type current sensing > chip. While I have found a few 120V-5V PT's my personal requirements > are 230V 10A. Potential Transformers that accomplish this feat seem to > be a little more rare. Does anyone out there know of somewhere I can If it's isolated from the user, and double insulated, a simple resistive divider may work well.
From: John_H on 19 Jan 2006 14:55 Why use a voltage transformer if high-value resistors work? just make sure you keep within the power and voltage constraints on the resistors in a resistor divider and you can sample within the range of your A/D converter. Easy! "Kit Talich" <Oxmmdox(a)gmail.com> wrote in message news:1137699828.652879.244910(a)f14g2000cwb.googlegroups.com... > Hello all! > > I am currently working on my senior design project of a Digital > Power Meter here at the South Dakota School of Mines and Technology > (Shamless plug!). I plan to measure and display Voltage, Current, Power > and Power Factor. To do this I plan to sample both waveforms and > calculate the rest. I have found a Hall Effect type current sensing > chip. While I have found a few 120V-5V PT's my personal requirements > are 230V 10A. Potential Transformers that accomplish this feat seem to > be a little more rare. Does anyone out there know of somewhere I can > find some of these? Small size would also be desired. > > > P.S.: Gimme a JOB! B.S. EE minor:CSC >
From: John Popelish on 19 Jan 2006 15:02 Kit Talich wrote: > Hello all! > > I am currently working on my senior design project of a Digital > Power Meter here at the South Dakota School of Mines and Technology > (Shamless plug!). I plan to measure and display Voltage, Current, Power > and Power Factor. To do this I plan to sample both waveforms and > calculate the rest. I have found a Hall Effect type current sensing > chip. While I have found a few 120V-5V PT's my personal requirements > are 230V 10A. Potential Transformers that accomplish this feat seem to > be a little more rare. Does anyone out there know of somewhere I can > find some of these? Small size would also be desired. Is that a request for a 230V to 10V PT? Are you willing to use an ordinary 10 volt step down transformer with a 230 volt primary? Is 9 volts out close enough? If so, you might look at some toroidal transformers with dual primaries (115-230). They have quite good voltage regulation under light load. http://rocky.digikey.com/WebLib/Amveco-Talema/Web%20Data/62000%20Series%20Low%20Profile%20Miniature%20Transformers.pdf
From: Joerg on 19 Jan 2006 15:12
Hello Kit, > ... While I have found a few 120V-5V PT's my personal requirements > are 230V 10A. Potential Transformers that accomplish this feat seem to > be a little more rare. Does anyone out there know of somewhere I can > find some of these? Small size would also be desired. > Buy them in Europe. Everything is 230V there. You can also buy current transformers (make sure to never, never leave the burden resistors off). Regards, Joerg http://www.analogconsultants.com |