Multiple doorbells - need a bigger transformer!

[OwainDIYer]

Can I use this for example?
http://www.tlc-direct.co.uk/Products/SK661406.html

RF - thanks for the detailed wiring info for the relay - can you just confirm that by using the relay (which is effectively the 'switch', yes?) I could use a normal 2A rated doorbell push and bell wire for each of the bells? I would need a transformer with output enough for 4 bells though?

Hmm -just re-read that and I'm not sure now... enough current is still required to operate the bells which if they are looped off each other would larger cable not be required? Think I'm a bit confused...

With the relay you have the bell transformer(s) (or battery(ies)) close to the bells, so voltage drop is minimised.

I think the plain piezo buzzers sound rather unattractive and I would suggest something like a
http://uk.rs-online.com/web/p/sounder/1967487/

connected up to give a 'yodel' tone. Power is 12 V DC at approx 25 mA and they panel mount so you could drill a blanking plate to match the other electrical accessories.

Alternatively use a relay from the bell push to run mains powered fire-bells.

 

[sparkybird]

Morning all!

And yes I can confirm that I'm a female... last time I checked anyway..

Just to recap

The is is a domestic property and for that reason the wiring/installation needs to be tidy with as much of it hidden (eg transformers) and wired not using mains cable.

The house is next door to a school with automatic gates and the client has tried several different wireless doorbells but has had interference problems with them all, so want's a wired solution

The relay idea - I now understand - the relay only helps with the switching and I'd need to fit a transformer at each bell - not something I really want to do as it involves trying to find somewhere to hide them on each floor, plus supplying each with 230V is going to be a PITA. Ditto mains pwered bells/sounders

The piezo sounders....
Owain - yes i was thinking of a two tone version as I think it'll be more suitable for domestic.

John - the buzzers all appear to be DC and as I understood it all bell transformer are AC - so can't see how that would work?

I need to find a way of mounting them neatly and ideally would be white to blend in :

How about fixing this to a blank plate, fitted to a shallow surface mount box, so I could do all the connections inside the box??
http://www.maplin.co.uk/3-tone-piezo-buzzer-4835
It's powered at 12v DC - so one of these would be OK - buzzers wired in series
http://www.tlc-direct.co.uk/Products/SK159278.html
Or one of these as I originally suggested
http://www.tlc-direct.co.uk/Products/SK661406.html

Or this one looks like it is surface mount.. but maybe a bit overkill for what is essentially a doorbell for a house
http://uk.rs-online.com/web/p/sounder/6173716/

Thanks again for all your input

SB

John - I know at least 10 female electricians, so maybe the're not that thin on the ground....

 

[OwainDIYer]

That little Maplin one I would fit to the inside of a blanking plate with a little hole to let the sound out. They may not work in series with each other.

The RS one is probably overkill but you could shove some cotton wool in it if it's too loud. With 10 tones you are more likely to find one acceptable to the customer (suggest demonstrating any purchases to the customer before fitting).

However I think a large part of the problem is volt drop on the cable. Decend Friedland Underdomes should work fine and give sufficient volume for a fair sized house - I lived in a 3-storey house and we had 1 underdome and could hear it everywhere. 3 should run in parallel off an 8V 1A bell transformer.

 

[JohnW2]

John - the buzzers all appear to be DC and as I understood it all bell transformer are AC - so can't see how that would work?

Whoops, yes, I wasn't thinking. However, there's no lack of 8-12V DC power supplies around, such as the one you suggested. Sorry for having confused the issue. As for the noise it makes, you can get piezo sounders in all flavours - buzzers, two-tone, multitone, sirens or even ones which play tunes.

John John - I know at least 10 female electricians, so maybe the're not that thin on the ground....

That's interesting (and makes sense). It must just be by chance that I've come across so few!

Kind Regards, John.

 

[sparkybird]

Owain - good tip about fitting the buzzer in the box - I guess I could contact Maplin and ask how they can be wired for more than 1 buzzer. The idea of using these piezo buzzers was the volt drop would not be such a problem - nor the rating of the bell push (2A). I'd definitely try one before committing!

I need to fit 4 bells on 3 floors of the house, so not sure if 4 would run off the 1A tranny, pus of course there's the volt drop issue. It was previously suggested that I could contact the bell manufacturer to find out what current they actually use ie if it's 0.25A then 4 could work OK...

John - we all seem to work in domestic, so maybe if this isn't your patch then that's why you've not spotted us!

SB

 

[JohnW2]

I guess I could contact Maplin and ask how they can be wired for more than 1 buzzer. The idea of using these piezo buzzers was the volt drop would not be such a problem - nor the rating of the bell push (2A). I'd definitely try one before committing!

You seem to still be thinking ("ask Maplin....") of wiring piezos in series, but I don't really see why. If you wire them in parallel, then there are no questions to ask - you just need to get a DC power supply of an appropriate voltage (and most piezos tolerate a wide range of voltages - like the one I linked to).

John - we all seem to work in domestic, so maybe if this isn't your patch then that's why you've not spotted us!

I don't really have 'a patch' as far as electrical work is concerned, so I only come across, or hear about, electricians by chance. However, as I said, it's just that I've come across many females in 'traditionally male' trades (e.g. plumbing, car mechanics, even construction), and have worked with many female engineers, but only very rarely have encountered female electricians - as I said, presumably just chance.

Kind Regards, John.

 

[big-all]

the more i think off it its very unlikely that 3 if not 2 bells will be more than enough for a 4 story house
after all how many 2 story houses need 2 bells

i recon if you fit 4 you will be called back after a few days to reduce the noise as"they are far noisier "than they thought

 

[Taylortwocities]

and have worked with many female engineers, but only very rarely have encountered female electricians - as I said, presumably just chance.

A couple for you to choose from...

Untitled

• Taylortwocities
• 4 Sep 2011
• 3

Untitled

• Taylortwocities
• 4 Sep 2011
• 1

Please state your preference, and the reasons why...

 

[JohnW2]

Please state your preference, and the reasons why...

The first one, I think - not so much for the 'obvious' reasons but, rather, because without additional data, I don't think I would be certain that the second one is female!

Kind Regards, John.

 

[sparkybird]

No, she is - she's smiling!

 

[JohnW2]

No, she is - she's smiling!

Hmmm - men have been known to smile as well, in appropriate circumstances Mind you, in favour of what you say, she does look a bit over-dressed (PPE-wise) for running a cable under floorboards!

Kind Regards. John.

 

[sparkybird]

Big - all

I agree and have just suggested to the client that we try with 2 or 3 under dome bells and see how he gets on

Thanks for all the input from everyone - it's been really useful and I've learnt a lot

SB (a bird)

 

[mattylad]

If the run was long and the actual bell current low I'd go for the higher voltage transformer setup at the bell button and make individual step down regulators for each one, a 7812 should suffice.

 

[DetlefSchmitz]

Depends what you're actually replying to, but 7812s aren't fond of a.c.

 

[ban-all-sheds]

The first one, I think - not so much for the 'obvious' reasons but, rather, because without additional data, I don't think I would be certain that the second one is female!

#2 doesn't look competent - cables in notches like that.

Still - she's obviously expecting to meet you, John - the gloves, goggles and hard hat are in case you come across her, you filthy brute.