Using Current Transformer to Step-Up Current

[turbo22]

I need to generate about 100 mA from a 60 Hz source by driving a GFCI grounded-neutral current transformer (in reverse). Neglecting transformer losses, if I use a 250 turn primary and drive it with 400 uA, theoretically, I should be able to extract 100 mA from a single turn secondary (a single conductor through the center of the CT). My burden on the secondary will be about 1200 ohms. Unfortunately, this won't work as witnessed by my SPICE model and breadboard evaluations. Obviously, I'm overlooking something important such as power out = power in (neglecting losses) in which case my primary side voltage should be Vsec x 250 = 30kV! Yikes! (And the 400 uA may not provide enough magnetizing force to generate the necessary magnetic flux).

I know this can be done once the CT, driving signal, and burden are matched correctly. Has anyone done this and would like to share the secret? I will personally see to it that Santa leaves you something special under the tree this Christmas...

 

[IRstuff]

I think you already answered your own question.

Since there is no free lunch, all your output power must come from the input side and your calculation looks about right. This is no different than the power company's step down transformers that provide your main power, where they start with something like 345 kV.

Since your input and output voltages are the same, you need to have a 1:1 transformer

TTFN

 

[electricuwe]

Using a current transformer in reverse is standard practice for supplying high currents for tests on relays, meters and current transformers. But this only works if the load connected to the single turn side has a very low impedance !