GFCI Plugs for Vintage TV???

[Bill R]

Originally Posted by markthefixer

The hot and neutral wires wrap through a toroid transformer core and constitute the primary of the transformer. Then they go to a PAIR of relay contacts hooked up to a spring loaded disconnect mechanism. The other side of the relay is the outlet plug. Meanwhile back at the transformer, the secondary has a gazillion windings, making it very sensitive. When the current going OUT the hot wire is EXACTLY balanced by the current going BACK through the neutral, there is NO magnetism induced in the transformer. When an inbalance occurs, then that sensitive secondary with the gazillion turns gets energized. Then an integrated circuit (usually) powered by the line (before the relay) senses the voltage and energizes a coil that trips the spring loaded disconnect mechanism on the relay , sort of like a mousetrap.
The hot and neutral open up immediately. No ground is needed.

.

Thanks for the explanation.