led doorbell switch

The LED is across the switch contacts. When the button is not pressed, the LED (and its series resistor) allow a small current to flow from the transformer and through the doorbell coil. Not enough current to move the doorbell striker, but enough to illuminate the LED.

When you press the door bell button, the LED will be shorted out, so it won't illuminate, and full current will flow to ring the chime.

Thanks for that, just thought there should be a return in order for the led to light.

KevinW said:

Thanks for that, just thought there should be a return in order for the led to light.

Click to expand...

As For The Popcorn stated, there is a return. It's just through the load (doorbell.)

Ok, thanks Chris, I have it now.