Detect the activation of a bell's door switch

[BiDoU]

Hi,

I want to detect when someone press the button of bell's door.
Maybe with a AC relay it's possible to do it? What is the best to detect it ? The transformer has 120V on side and on the other it's 18 VAC...

I uploaded what the circuit of the bell's door like...

 

[gerty]

Your circuit will work for as long as the button is pressed, as soon as the button is released the relay will drop out.. Is that what you want ?

 

[Sebi]

When the AC relay not available...

 

[BiDoU]

Your circuit will work for as long as the button is pressed, as soon as the button is released the relay will drop out.. Is that what you want ?

Yes, the contact of relay will activate a input of a microcontroller...

 

[BiDoU]

When the AC relay not available...

Thank you, I didn't know that I have just to put a bridge rectifiers to use a DC Relay.

 

[Sebi]

For microcontroller interfacing more elegant an optocoupler...

 

[BiDoU]

For microcontroller interfacing more elegant an optocoupler...

Ok thank you !