Aphiliac,
Let me refresh what you were reading.
On December 9, 2016 at 15:40, Ernie Gilman said...
I've considered powering a Doorbird from the old-timey doorbell wires in the house, and in fact the instructions say you can do this.
I said nothing about using the doorbell transformer, because the Doorbird instructions tell you that you have to remove the doorbell transformer and put the Doorbird supply in its place. (At least that's what I remember.) Now that I've said that, back to my quote:
There's no mention of taking the actual doorbell out of the circuit if you replace the doorbell transformer with the Doorbird transformer.
I could be wrong. Again, that's what I remember reading.
It could work with the doorbell still in the circuit, if the Doorbird's current requirement is low enough.
See, the question is, since the Doorbird instructions don't tell you to remove (and short together the wires of) the old doorbell, are doorbells so low in resistance that the Doorbird will work with a doorbell in series with the Doorbird?
Is that any clearer? It's what I intended. Sorry if I left out detail, which, of course, always makes posts longer....