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Current transformer

Started by Tim Williams November 30, 2011
Would've been nice if I had known a current transformer isn't a very good 
transformer. Instead of two terminals, it acts more like a single 
terminal, with your poor burden resistor caught in the middle.  Ah well, 
such is basic research...

Tim

-- 
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms 


Tim Williams <tmoranwms@charter.net> wrote:
> Would've been nice if I had known a current transformer isn't a very good > transformer. Instead of two terminals, it acts more like a single > terminal, with your poor burden resistor caught in the middle. Ah well, > such is basic research...
What?
On Wed, 30 Nov 2011 18:23:18 -0600, "Tim Williams"
<tmoranwms@charter.net> wrote:

>Would've been nice if I had known a current transformer isn't a very good >transformer. Instead of two terminals, it acts more like a single >terminal, with your poor burden resistor caught in the middle. Ah well, >such is basic research... > >Tim
What? John
"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in 
message news:ocldd7d2d4f9pqu02ucoqbbqb88i9qa54t@4ax.com...
> On Wed, 30 Nov 2011 18:23:18 -0600, "Tim Williams" > <tmoranwms@charter.net> wrote: > >>Would've been nice if I had known a current transformer isn't a very >>good >>transformer. Instead of two terminals, it acts more like a single >>terminal, with your poor burden resistor caught in the middle. Ah >>well, >>such is basic research... >> >>Tim > > What? > > John >
Let me help you.... Here's the Jive Translation: Would've been supa' fine if ah' had knode some current transfo'ma' isn't some very baaaad transfo'mer. Ah be baaad... Instead uh two terminals, it acts mo'e likes some sin'le terminal, wid yo' poo' burden resisto' caught in de middle. What it is, Mama! Ah sheeit, such be basic research... Cheers

"Tim Williams" <tmoranwms@charter.net> wrote in message 
news:jb6hf9$1rt$1@dont-email.me...
> Would've been nice if I had known a current transformer isn't a very good > transformer. Instead of two terminals, it acts more like a single > terminal, with your poor burden resistor caught in the middle. Ah well, > such is basic research... > > Tim > > -- > Deep Friar: a very philosophical monk. > Website: http://webpages.charter.net/dawill/tmoranwms >
All transformers are current transformers, see the Faraday's lows of mutual induction. In practice it can be configured in current, voltage or power mode depending on application. Mathew Orman http://www.faster-than-light.us/
John Larkin wrote:
> > On Wed, 30 Nov 2011 18:23:18 -0600, "Tim Williams" > <tmoranwms@charter.net> wrote: > > >Would've been nice if I had known a current transformer isn't a very good > >transformer. Instead of two terminals, it acts more like a single > >terminal, with your poor burden resistor caught in the middle. Ah well, > >such is basic research... > > > >Tim > > What?
His current transformer is out of date... -- You can't have a sense of humor, if you have no sense.
"admformeto" <admformeto@onet.eu> wrote in message 
news:jb6n5i$u9u$1@dont-email.me...
> All transformers are current transformers, see the Faraday's lows of > mutual induction. > In practice it can be configured in current, voltage or power mode > depending on application.
News to Faraday, my transformer doesn't transform. At least, not very well. At least, not within the first, about a microsecond. Simple example: go buy a bog standard Triad CT206, it rings like a bell at a rather low frequency (a MHz or so)! In fact, I'm pretty sure it's acting as a toroidial resonator, which isn't much heard of, helical resonators are more common. Same idea, but with four quadrants. Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
"Tim Williams" <tmoranwms@charter.net> wrote in message 
news:jb6pg4$931$1@dont-email.me...
> "admformeto" <admformeto@onet.eu> wrote in message > news:jb6n5i$u9u$1@dont-email.me... >> All transformers are current transformers, see the Faraday's lows of >> mutual induction. >> In practice it can be configured in current, voltage or power mode >> depending on application. > > News to Faraday, my transformer doesn't transform. At least, not very > well. At least, not within the first, about a microsecond. > > Simple example: go buy a bog standard Triad CT206, it rings like a > bell at a rather low frequency (a MHz or so)! > > In fact, I'm pretty sure it's acting as a toroidial resonator, which > isn't much heard of, helical resonators are more common. Same idea, > but with four quadrants. > > Tim > >
Your using it as an air core transformer. Didn't Telsa invent something similar ;) Cheers
"Martin Riddle" <martin_rid@verizon.net> wrote in message 
news:jb6qcc$cq8$1@dont-email.me...
> Your using it as an air core transformer. Didn't Telsa invent something > similar ;)
It sure feels like it, but I'm pretty sure the core is still mu_r >> 100 at whatever resonant frequencies these things are doing it at. I'd call it a ferrite-loaded helico-toroidial resonator, or something ungainly like that. Since L is large, that means F is small (~MHz), and the impedance is high -- sadly, the Q is also high, so the impedance (ESR, since it's a series resonant equivalent) at the feedpoint (i.e. burden R) is very low. It's very interesting to rotate the "primary" around the core and watch the nodes in the standing wave. I should see about making an air-cored version, driving it with RF and putting it in a low pressure neon environment or something. Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
Tim Williams wrote:
> Would've been nice if I had known a current transformer isn't a very good > transformer. Instead of two terminals, it acts more like a single > terminal, with your poor burden resistor caught in the middle. Ah well, > such is basic research... > > Tim >
Huh???