How many Transformers do I need?

I have 3 video doorbells (for 2020 release). I’m tired of charging them so often, so I’m hardworking them. Do I need a transfer for all 3 doorbells, or can I use 1 transformer to power all 3? Also, if 1 transformer will power all 3 doorbells, do I need a separate resistor for each doorbell, or just 1 total? Thanks in advance!

Hi @bilco82. You do not need a resistor for the Ring Video Doorbell 2020 Release. This Help Center article here has a few diagrams that might help. I would suggest using a 16V 30VA transformer, which can be found here.