Doorbell Transformer for 3 bells??

[Lester Lecky]

Hi all

I'm sure its been asked before but i'm looking to convert an existing Mains doorbell system with 1 bell so that it has 3 bells. The system only has a 1amp transformer. I was wondering if anyone knew where i can source a 2A or 3A 8V transformer to supply the 3 bells?? I know Byron do a 2A (7781) and friedland (E3554SN) but can't find anyone who sells them locally. Do you know any suppliers who sell these bigger transformers (or alternatives) off the shelf??

All helpful comments most appreciated?

---------- Post Auto-Merged at 18:10 ---------- Previous post was made at 17:57 ----------

Unless of course there is someway to incorporate another 1A transformer off the same bell-push but not sure this would work - Having 2 transformer outputs interconnected via one bell-push?

 

[alpha spark]

Can you not get a 12 volt psu some white fire alarm sounders that have dill switches and change the sounds so each bell has its own sound we do this a lot in shop fitting when front door back door and counters all need a different sound I know it costs a lot more than door bell transformers but least it's another option

 

[Evans Electric]

Order one in then Lester or try RS .

What is the current for 3 X doorbells @ 8V . Never really thought about it .

 

[Lester Lecky]

Thanks for suggestion. Job is on a tight budget so may not be an option. Different sounds not required - just "ding dongs" in 3 parts of a house. Would a 12V PSU be suitable for 8V doorbell system? If so how big are the ones you are talking about - there's limited space on existing system - product suggestions/links?

Thanks Again Alpha Spark

 

[alpha spark]

http://www.cts-direct.net/rgl-cp12204-12v-dc-2-amp-cw-4-x-05-outputs-psu?language=en&currency=GBP&gclid=CO6Eg5ev_rECFYcPfAodFWwAPw

So u want all 3 bells to ring of one bell push

 

[Lester Lecky]

Thanks Evan Electrics. I imagine/estimate each doorbell is about 0.5 - 0.7 A amp?? They are just typical Byron & Siemens doorbell ringers (Usually take 4 C type batteries etc)

 

[alpha spark]

Or possibly use a relay

Let the push power the coil !

 

[Evans Electric]

I'm only guessing but I'd say an standard Friedland would power 3 X Ding-Dongs without any problem , probably using the 12V terms . Ding-Dongs use a little solenoid . Give it a try .

 

[Lester Lecky]

Yes i want all three "Ding dongs" to go at the same time so home owner can hear bell in various parts of house.

Tried rigging up the extra 2 bells onto existing 1A byron tranny and it did not like it - not enough juice it seems for the 3 solenoids - just about did two bells! Hence my thinking of a bigger Tanny!

Has a standard Friedland got both 8V & 12V output options then Evans Elec?? Still not sure if enough current ouput though?

Thought of a relay, but the 3 bells still need supplies - one 1A trany not enough it seems

Thanks for all replies

 

[alpha spark]

Use 3 trannies 1 for each bell via a relay so when push is pressed it sets of all 3 bells

 

[Lester Lecky]

Hi Alpha

Yep understand 3 trannys required. But converting exiting system. Just wanted to piggy back off existing bell rather than run extra cables to each bell. But still a good suggestion thank you. I'm hoping a bigger tranny will do the job - thats the hope but struggling to source one and be sure it will do the job. My usual local wholesalers not interested. May have to try CEF or someone - hoped to get one of the shelf rather than order one in especially with carriage charges etc - customer don't want to spend more than about

 

[Evans Electric]

Yes , depending on model , Friedlands often have 4V---8---12V . Think you'd best get an RS one ,

 

[husky2013]

eibmarkt.com - Bell transformer 4V/8V/12V - GT 3174

maybe this will help, they do several variants.

hth x

 

[NozSpark]

If you have trouble getting a 3A transformer then you could parallel up 3 x 1A ones,,,, but can the cable take it (current and volt drop)???

 

[Lester Lecky]

Wondering if you can get problems with wiring up transformers in parrallel? I have read that unless perfectly balanced on output they can feed in to each other and overheat? Just a thought?

I may stick to plan A and continue to search for a 2Amp tranny locally and hope that has enough juice to power the 3 ding dongs.

I have very limited physical space so a transformer in an enclosure as previously suggested may not physical possible.

Think i'm gonna try rigging up 2x1A trannys in parallel temporarily to see if 2A will be enough for the 3 bells. if so then track down a 2A tranny!!!

The 3 bells are going to be supplied in parallel using 6 core alarm cable - 3 cores per connection to help with volt drop - i.e. thicker wires overall than bell wire. Only doorbell wire will be still bellwire - may have to upgrade that if possible.

Fingers crossed!!

 

[roys]

Not sure on this idea but how about a switch mode power supply as used by laptops, they are small compact and a decent current output on them.

 

[Apache]

Thanks Evan Electrics. I imagine/estimate each doorbell is about 0.5 - 0.7 A amp?? They are just typical Byron & Siemens doorbell ringers (Usually take 4 C type batteries etc)

Ok, so 6V gives you enough for two but not enough current for 3 bells. Up that to 12V and you half the current so you should be fine? No?

 

[Lester Lecky]

Update. Introducing a second tranny in parallel - worked! There was enough Current to ring the 3 bells satisfactorily. Disconnected now as not sure if trannys would overheat due to concerns pre-mentioned.

I also sourced a 2A bell tranny (now ordered) and so will install that and hopefully all will be good.

Thanks for all comments and helpful posts. Plan A will hopefully be the successful one!

 

[Doc Hudson]

Surely not that complicated to get a suitably rated PSU from Maplins or similar outlet and do a few ohms-law calcs?

Doc H