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Pulling chime off doorbell circuit

IVB

Senior Member
I'm sure this is old-hat for many of you, i'm a newbie with the Elk stuff so i'm still discovering how powerful this thing is.

I was learning the ElkRP software tonight by mucking with my doorbell & the Elk Doorbell ring detector when I woke up my 2yr old with the incessant dinging. Wife didn't get bugged as she was working on some stuff, and just looked at me and said "you woke her up, you get her. Can you do something about that doorbell btw? It's seriously loud". [the doorbell is a non-elk thing, just some cheap $10 POS i picked up at HD].

So, that got to thinking - I need some easy way to have a "quiet - kids are sleeping" mode and a "loud - kids are awake" mode.

I've got the Elk doorbell ring detector, which takes the normally open doorbell circuit and when the button is pushed, tells me. I could just take the chime off that circuit, create a different circuit with some form of contact closure, hook that up to an output off the Elk, and put the chime & also tap into the same transformer there.

In quiet mode, the Elk wouldn't complete the contact closure, but i could have it do something else. [ie flash lights]. In awake mode, it would close the circuit.

I could use either CQC, Elk Keypad, or any other input device to switch from quiet mode to awake mode.

Anything wrong with that plan? Any issues with using that same 16v/15w transformer for both circuits?
 

Chakara

Active Member
I didn't quite get your 4th paragraph, however I think you can do what you want. I'd eliminate the "$10 POS" entirely....

I think doorbells work with a switch, lamp and resistor in parrallel. If I'm right you could do something like this:

doorbell.jpg


Then program rules for announcements / lamps / whatever based on whatever you want for when the button is pushed.

You guys think that would work as that is what I'm thinking for mine? What value is in the switch itself and what do you recomend for the current control resistor?
 

MrGibbage

Active Member
(Ever so slight thread hijack, but you got me thinking)

Do I need to have my builder do something special to ensure that my Elk can detect my doorbell? Is it easy enough to add a doorbeel detector to an existing circuit? What would you do to make the setup as easy as possible?
 

IVB

Senior Member
MrG: As long as you got a wired doorbell, the Elk detector is pretty simple to add. You just put the board somewhere along that run, and then run 2 wires back to the Elk main board.

Chakara: Your path would result in the device always going off upon doorbell ring. What I want to do is create a "quiet" mode and a "noisy" mode where I sound the doorbell or not. Of course, as I type this, I just realized that with the Elk, I can setup rules as to whether to send signal to an output or not. I've only just started reading up on the rules section, but I *think* it would look like:
Whenever Doorbell button pushed AND mode=naptime THEN flash the strobe.
Whenever Doorbell button pushed AND mode=noisy THEN sound chime THEN flash strobe.

I need to research how to do the mode thingey, all that sounds logical.
 

Chakara

Active Member
It's probably not clear on my drawing, my my interntion is to remove the $10 POS doorbell and replace it with a resistor. Then do exactally as you said and let the Elk become the doorbell. Hopefully some of the smarter people on here can help out with what value that resistor might be....
 

upstatemike

Senior Member
As I understand it, the Elk device goes in series with the doorbell and detects current drawn through it. Doesn't that mean anything that silences the doorbel also interupts current flow and prevents detection?

My approach was to replace the doorbell with a double pole relay. One set of contacts feeds the original doorbell and the other signals the automation system. I can interupt the doorbel to silence it but maintain input to the HA system.
 

IVB

Senior Member
Slowly absorbing what you both are saying, but yes, i think that double-pole relay was what i was badly trying to say. Is that an Elk product or a generic product?
 

upstatemike

Senior Member
The answer depends on whether you have lighted doorbell buttons or not. The lights work by drawing a little power through the doorbell coil to light the light. Because it is a fraction of the current needed to ring the bell, it works great but a relay will have a different coil resistance and lower trigger threshold so the light might be a problem.

The clean and sure solution is this:

Buy a cheap dorbell at home depot for under $10. Disable it mechanically by removing the plunger so it has the same electrical characteristics as a working doorbell but makes no sound.

Put this unit near your panel and rewire your doorbells so the buttons ring this disabled unit instead of the real one. Keep the Elk 930 doorbell detector in the circuit just as it is now. This gives you lighted doorbell buttons that trigger the Elk module but do not make any sound.

Use the Elk 930 doorbell detector(s) to activate a pair of Elk 912B relays. If you are using 2 930 detectors for front and back doors you will need a pair of relays for each door.

You now have 2 sets of dry contacts that close when the doorbell buttons are pushed. One set of contacts for each door are used to operate the real doorbell. You can enable or disable (silence) this doorbell by using a relay from your contoller. (There are a number of different options for wiring this).

The other set of contacts from each door can be used to signal your controller that the doorbell button was pushed so you can have a voice announcement or whatever.
 

MrGibbage

Active Member
Still trying to figure out if I should pre-wire my doorbell. I'm a pretty technical-savy person, and can find my way around a wiring diagram quite well, but I think that if I were to try and hook up something electrical to an existing doorbell circuit, that I couldn't do it and run the wires to my wiring closet without keeping it looking neat and professional and finished (and keep the wife happy). I guess I could go to the door bell itself (not the switch), connect the wires, push them back into the wall, fish for them and then hook it up to the Elk, but that sounds like a lot of work. Since I am building the house now, would it make sense to pre-wire something?
 

upstatemike

Senior Member
CORRECTION

I just noticed that the Elk 930 Doorbell detector can only sink about 40mA (lame) so it will not drive a pair of ELK 912B relays @ 35mA apiece.

Instead of the 2 Elk 912B relays for each door substitute 1 Alarm Controls 8007 relay. These devices only draw about 12mA and have 2 sets of contacts so you only need 1 relay per door.
 

upstatemike

Senior Member
MrGibbage said:
Still trying to figure out if I should pre-wire my doorbell. I'm a pretty technical-savy person, and can find my way around a wiring diagram quite well, but I think that if I were to try and hook up something electrical to an existing doorbell circuit, that I couldn't do it and run the wires to my wiring closet without keeping it looking neat and professional and finished (and keep the wife happy). I guess I could go to the door bell itself (not the switch), connect the wires, push them back into the wall, fish for them and then hook it up to the Elk, but that sounds like a lot of work. Since I am building the house now, would it make sense to pre-wire something?
Have your builder home run the doorbell buttons and the chime back to your wiring closet and tell him that is where you want the doorbell transformer located. He can then wire it normally and you will have access to everything in case you want to change it in the future.
 

toymaster458

Active Member
Wouldn't this work just as well?

doorbellmuter.jpg


The M1 would still detect the doorbell and control which bell would be rang a long with keeping the button light. Then if the M1 is off for any reason the normal door bell would still work.
 

IVB

Senior Member
Mike/toymaster: I don't actually have a lighted doorbell - very rustic Resto Hardware thing. Is that what's driving the dummy bell in your posts?
 

toymaster458

Active Member
There is another way it could be wired up for non lighted doorbell buttons but the way I have it, the doorbell will default to non-muted if the M1 was turned off or removed for any reason.
 

upstatemike

Senior Member
That plus you need current flow for the 930 to detect even when in silent mode. Toymaster's solution is simpler and nicer than what I was describing.

You could also use 12V from your panel to have the doorbell buttons operate relays directly and have the relay contacts ring the doorbell and provide a closure to your panel but since you already have the 930s I would lean towards Toymasters suggestion.
 
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