This circuit is an Automatic Cut off Switch for Egg boiler. It connect the mains voltage when you press the push button for 1 second, then disconnect the mains when the thermal switch inside the egg boiler cuts off.
You have to wrap several turn of wire to increase the sensitivity of the current transformer.
Parts list:
Current transformer 2000:1
Solid state relay 2A or more (depends on your load)
LED
Capacitor 220uF 16V
Momentary push button switch 3A 250V
Plastic box enclosure
Circuit:
Watch this video for more details: