What do you think of this, could the meter that is measuring the input current be incorrectly reading when it drops under load maybe because of the cfl, it seems strange he has so many turns.
Nothing strange about this video except that it is very misleading. The CT is in saturation with no load, so he sees the higher amps delivered to the heater in that case.
With a small load on the secondary, the CT is taken out of saturation and the series impedance to the heater increases dropping the amps to the heater slightly.
With the CT out of saturation it is able to act like a normal transformer and transfer some power to the secondary CFL load. The missing amps on the primary now appear on the secondary.
This guy need to understand the nature of transformers in saturation and how a secondary load can pull the transformer out of saturation. This is true for any transformer with a fairly tight magnetic structure with no air gaps that is operated close to or at saturation.
The only thing out of the ordinary about this is he added the return current for the primary in an 'aiding' configuration.
This will double the secondary power output ability. It doesn't change the result, as ION has explained.
The very high secondary turn count to provide 150V is because the primary voltage is only the voltage drop across the primary. If he has 4000 turns on the secondary with 150VAC output and about 20 turns on the primary the voltage drop across the primary is around .75VAC.
So, any power output of this CT is included on the reading from the utility power meter :(
Thanks guys i should have worked that out.
A CT is just a transformer but many (Including several EEs I know) can't tell you how they work, correctly.
So don't think less of yourself for not seeing the truth about this sooner. I'm sure you will catch me making mistakes on digital devices.
I hope you will :)
Thanks WW
It's so easy to make a fool of oneself with this stuff, well it is for me anyway. C.C
That was so basic i should have thought about it a bit more really
Quote from: Peterae on 2011.08.07, 21:08:19
What do you think of this, could the meter that is measuring the input current be incorrectly reading when it drops under load maybe because of the cfl, it seems strange he has so many turns.
Just so everyone knows, this clip was removed due to "terms of service" violations. That's what I got when I clicked on the right-justified triangle.
Just checked it again in Preview. It's gone.
--Lee