voltage drop thru doorbell button

[GerryB]

Always learning here. So a lengthy run or multiple chimes like a 3-family house a 30va tranformer would be the way to go.

 

[kwired]

I seem to remember that some door bell buttons had the light in series and if the light burned out, the door bell would not work.

That would account for a sizable voltage drop if that is the kind of switch being used.

How is that possible to make work? to have a lighted button the switch needs to be closed if in series. It would work if you desired the button to light when the chime sounds - but will have a voltage drop across the light and through the chime to consider in the design, let alone VD over conductor length.

You are forgetting that according to the OP the same 100' of wire with the leads twisted together at the button location produced 25V at the chime.
(Unless that was measured with the chime disconnected, maybe?)

I kind of thought he hinted that it possibly was with no load when he was reading 25 volts, but this has not been clarified either.

You do not increase the voltage with 2 chimes but rather you increase the VA. When we have 2 chimes I use a 16v 30va trany and it works fine. I suspect people use the tri tap trany where the 30va tap is 24V.

Something like this

Increasing source volts may very well get you by in many cases, though a higher VA rated transformer is the correct thing to do. You will as mentioned burn out more lamps in lighted buttons though.

 

[James L]

Increasing source volts may very well get you by in many cases, though a higher VA rated transformer is the correct thing to do. You will as mentioned burn out more lamps in lighted buttons though.

Especially if the voltage drops to 19, then yes - a 24 volt transformer would work.

I'm not sure what the chime draws, but I would suspect somewhere around 10-12 VA . Two chimes would be in the neighborhood of 1.5 amps

With enough conductor length, I could see voltage dropping to 19 with the button pushed.


But you're right, increasing transformer VA is best.

 

[Electric-Light]

Interesting. Why 16V? What is the use of the 8v winding? I get that you can select either 16 or 24, but the way it's labeled suggests there's a use for 8v on its own as well.

 

[GoldDigger]

Interesting. Why 16V? What is the use of the 8v winding? I get that you can select either 16 or 24, but the way it's labeled suggests there's a use for 8v on its own as well.

I suspect that it is there only because otherwise people would ask "What would I get between those two terminals?"
If you are going to label, you might as well go all the way, and it might even be a UL requirement for all I know.