LED circuit

I'm not sure i understand when this LED is on and when its off.

Could someone explain it to me please?

Thank you.

The mains voltage is AC that swings positive then negative over and over.
The LED works from DC so the rectifier diode rectifies the mains voltage so it produces only humps of positive voltage.
The LED lights each half cycle of the mains that is a positive voltage.

alphacat said:

I'm not sure i understand when this LED is on and when its off.

Click to expand...

The LED is normally on when power is applied. If one of the fuses fails (either the thermal fuse or the line fuse), the LED is off.

Thank you fellows.

Doesnt it take a relatively high power rated resistor for that?