Two different battery operated door bells on one doorbell sw

[NickB_99]

Hello all,

I bought a Friedland battery operated doorbell from wickes. It takes 3x AA batteries. Wired it up to doorbell switch and works fine.

However, it can't be heard in the hall near the front door. So I bought another cheapie battery operated doorbell (a Byron one from screw fix) which requires 1x 9v battery. I went for this as it came with spare wire and a new switch if I needed one.
When wired to the switch this one works fine in isolation also.

However, I was thinking I could just use a little chock-block to switch both bells at the same time. Single pair from the switch, and a pair running to each doorbell. A 'Y' if that helps.
In this configuration, only the Byron one works. If I disconnect the battery from the Byron, then the Friedland one works again.
Hoping for some help :-S

 

[footprints]

Well you are joining a 9v battery to a 5.5 volt one, that might cause problems, but just maybe the polarity is different on each bell you could try reversing one set of wires at the y junction.

Reversing the polarity always works in sci-fi movies

But then I ain't a sparks

No doubt you will get better advise like NO NO NO! you will fry the 5.5v bell!! from somebody that knows what he is doing later but that's my thought.

 

[OwainDIYer]

Start by two bells that use the same voltage, and use one set of batteries to run both.

Easiest is to use two chimes such as
http://www.tlc-direct.co.uk/Products/VE107.html

and wire up as

View media item 50324

 

[NickB_99]

Footprints - good idea, but tried and it didn't improve things.

Will have a go at matching ones.

Thanks for the replies.

 

[winston1]

Maybe a diode in series with each bell will help.

 

[JohnW2]

Maybe a diode in series with each bell will help.

To be clear, the diodes would have to be between one side of the common switch and each of the two bells (the other side of the switch going to both bells). If batteries were functionally 'the same way around' in both bells and the diodes the correspondingly right way around (and man enough for the current involved), then that ought to work. If it wasn't late at night, I'd draw a diagram

Kind Regards, John

 

[davelx]

Maybe a diode in series with each bell will help.

To be clear, the diodes would have to be between one side of the common switch and each of the two bells (the other side of the switch going to both bells). If batteries were functionally 'the same way around' in both bells and the diodes the correspondingly right way around (and man enough for the current involved), then that ought to work. If it wasn't late at night, I'd draw a diagram

Kind Regards, John

I'd just use a double pole relay to keep the two bells' circuits separate.

 

[JohnW2]

I'd just use a double pole relay to keep the two bells' circuits separate.

Yes, that's another approach. It wouldn't necessarily even need to be a DP relay - if the coil were fed from the switched supply to one of the bells, you'd just need SP contacts to work the other one.

However, I do agree that, per OwainDIYer, the neatest solution is probably to use two identical (or, at least, same voltage!) bells with just one switch and one set of batteries.

Kind Regards, John

 

[bernardgreen]

Running two bells from a single battery and a standard door push button can result in a short life time for the push button due to the high current it is switching and a double dose of back EMF from the two bells. ( assuming they are bells with coils and not electronic ones )

The relay idea is a good one. and allows for two different types of bell ( voltage wise ) to be used

 

[JohnW2]

Running two bells from a single battery and a standard door push button can result in a short life time for the push button due to the high current it is switching and a double dose of back EMF from the two bells. ( assuming they are bells with coils and not electronic ones )

True in theory - but, unless one were running a very busy brothel or suchlike, I very much doubt that you'd see any problems for very many years with a pair of domestic bells!

Kind Regards, John

 

[footprints]

Running two bells from a single battery and a standard door push button can result in a short life time for the push button due to the high current it is switching and a double dose of back EMF from the two bells. ( assuming they are bells with coils and not electronic ones )

True in theory - but, unless one were running a very busy brothel or suchlike, I very much doubt that you'd see any problems for very many years with a pair of domestic bells!

Kind Regards, John

 

[EFLImpudence]

What's a brothel?

Is where they make soup?

 

[JohnW2]

What's a brothel? Is where they make soup?

Possibly

Kind Regards, John

 

[endecotp]

Maybe a diode in series with each bell will help.

I think you just need one diode, in series with the lower-voltage bell.

I.e.:

- Connect the two negative wires together, and connect to one side of the button.
- Connect the positive wire from the higher-voltage bell directly to the other side of the button.
- Connect the positive wire from the lower-voltage bell to the button via a diode.

Ideally you should use a Schottky diode because of its lower voltage drop. Buy 10 for a pound on ebay.

This does all depend on the bells not having any electronics in them.

 

[bernardgreen]

If both the bells are "ding dong" ( ding when button pressed and dong when it is released ) and are the same type then connecting bells, batteries and push in series will work.


X----Bell A-----Batt A+ --------Bell B-------- Batt B+---------Push-----X

where X connects to X to complete the loop.

The order is not important.