Doorbells and Voltage drop

[Nigel62]

Hi All

First posting to the forum so I hope that I've posted in the correct place.

I'm looking to install a doorbell at my home in France. The distance between the bell push and the location of the bell/chime is about 40 m. I originally wanted a battery operated unit but I've been warned that, because of the distance involved, the voltage drop will be too high to operate the bell. I've also been told that this would apply to a transformer operated unit as well. Wireless units don't operate (past experience) due to the thickness of the house walls/configuration of line of sight.

Can anyone please advise me of a suitable solution, as when it comes to voltage drops I quickly need to reach for the nearest alcoholic beverage!!

Many thanks guys.

 

[Pete999]

Get a wireless bell

 

[Lucien Nunes]

Using heavier cable and/or higher battery or transformer voltage will solve this. The drop will depend on the current demand of the bell. 40m of 1 mm² has a resistance of about 1.5 ohms. So the source needs to be increased by about 1.5V for every amp of current used by the bell. If using skinny cable of say 0.25mm² (four times the resistance) you would need to add four times the extra voltage, or 6V per amp of bell current. Just run it in 1.0 and will probably be fine as-is.

 

[Pete999]

https://www.google.co.uk/search?q=w...hannel=sb&gws_rd=cr&ei=vMM2VIbaKY6M7Abem4HIDw

 

[Octopus]

Take a look at Friedland UK's site and see what they say!

 

[UKMeterman]

You might find that you can use the push to control the coil of a small relay, the contacts of the relay wired in place of the push.

 

[tazz]

The voltage range over modern doorchimes, is anything from 3v to 10v. With most electronic chimes containing regulators, 1-1.5v volt drop is not going to make a difference.

 

[Knobhead]

No volt drop

 

[7029 dave]

Get a wireless bell

With you pete, that's some length. lol

 

[Guest77]

With you pete, that's some length. lol

I got one which works at around 40 mtrs, I have had the reciever at the top of my garden before and it rings, the only set back with these are the pushes IMO, they seem to break easy, not visually but something inside, I seem to have to change the push every couple of years and before you ask it is not the battery in it lol

 

[trev]

There's these things called mobile phones you know lads.
Visiteur- Bonjour Franque, Est tu dans la maison?
Franque - Mais oui, pour quoi?
Visiteur- Ouvré la porte. Sacré bleu!
See, easy. No volt drop, no wires.
That'll be a £375 call out fee please

 

[Jurassic Sparks]

Nigel
that is soem big house
40 metres
perhaps a butler would be the thing !!
had a similiar problem a few years back, we got round it by using a 240v bell push ( quite a chunky thing with a Neon) this clicked a relay in the main house and I used that to trigger soem door bells linked to a tranny ( the electric sort not a cross dresser)
regards jurassic Sparks
both old and stupid !

 

[Nigel62]

Using heavier cable and/or higher battery or transformer voltage will solve this. The drop will depend on the current demand of the bell. 40m of 1 mm² has a resistance of about 1.5 ohms. So the source needs to be increased by about 1.5V for every amp of current used by the bell. If using skinny cable of say 0.25mm² (four times the resistance) you would need to add four times the extra voltage, or 6V per amp of bell current. Just run it in 1.0 and will probably be fine as-is.

Thanks Lucien. So if I've understood correctly, if on a short run of say 5 m a 6V (1A) battery operated bell worked with normal bell wire, for my 40 m run I'd need to up the voltage to 7.5V (minimum) and use 1.0 mm2 cable?

 

[Nigel62]

Nigel
that is soem big house
40 metres
perhaps a butler would be the thing !!
had a similiar problem a few years back, we got round it by using a 240v bell push ( quite a chunky thing with a Neon) this clicked a relay in the main house and I used that to trigger soem door bells linked to a tranny ( the electric sort not a cross dresser)
regards jurassic Sparks
both old and stupid !

Thanks Jurassic. Actually we had a butler a few years back...only joking. Not sure about relays. In case I can't get an easier (for me) option to work could you point me towards a suitable one and explain how to wire it up please?

 

[UKMeterman]

Hi,
The loop resistance will be about 15 ohms, so you need something like Buy Solid State Relays Solid state relay, SPST-NO, 5 A, panel Schneider Electric 70S2-01-A-05-S online from RS for next day delivery. if you want the standard 6V battery ding dong. Ask the customer what kind of bell they would like and how many.