Add an Old door bell to HAAS

Hardware
1

Hi,

I’m thinking to work a new small projet. The Goal is to convert an old door bell.

Currently It’s compose of :

  • a button
  • a hager N212/SU212 (the bell working with 8-12v ~)
  • a Legrand 04220 transformer (220v ~ to 8v~)

My first idea is to get the 12v ~ on the Bell, add a diode bridge and command a relay 12v.
Relay with be set to ON when it rings.
I still do know how, but I will connect the relay to an ESP-12 and push status in MQTT.

My Second idea is to detect the close circuit when the button is pushed, but I don’t know how I can make this.

Any idea is welcome.
Thx for your help.

1 Like
2

How about like how I did it?

http://www.cribbstechnologies.com/index.php/home-automation/mqtt-integrated-doorbell/

I’m planning on using an AC-DC buck converter to power the project so it can run off of post-transformer voltage

3

Thx for your sharing !

Hum, it seems really interesting. I think it’s one of the best way I’ve seen for now.
I have to check if the transistor is needed, it’s something I have to order :slight_smile:

Power from AC is a good idea too, I think I can convert to DC with diode bridge, then use a 7805 or/and a LM1117 to power ESP and Relay.

4

I think the Keyes relay has a transistor built in. I’m using a Chinese knockoff