Brand new to forum, so hope I'm not breaking any rules by posting this. I did search the forums and the google machine for the last few days to try and get some knowledge transfer happening. I have my first arduino on order, including beginners starter kit, and looking forward to working with it when it gets here.
I also apologize in advance for the 'wordiness' below... I just couldn't think of how to explain it any more concisely.
Ultimately my goal is to add functionality to my existing 1950's-style lighting automation by introducing the arduino in order to set simple on/off lighting schedules and webpage interface to control via phones/tablet/computer.
I just moved into this house. It was built in the 50's, and it has TouchPlate low-voltage wiring to SPST latching relays for controlling the lights. The light switches on the walls have low-voltage wiring running to panels in the basement, connecting to the low-voltage side of about 40 relays; low-voltage side of the relays is powered by a 30Vdc transverter; the high voltage to the lights comes into these panels and connects to the high-voltage side of the relays. Since it's kinda cool now to have a panel in the master bedroom that can turn on/off all these lights, I'm sure it was way cool back when. You can find a basic picture-pdf of the setup at this touchplate website: http://touchplate.com/wp-content/uploads/2013/12/touchplate-old-system.pdf
My research of the relays tells me they need at least a 28.5Vdc pulse to switch on/off.
I'm not looking for 'the answers' so much as direction on which options I should consider to power the arduino and use it to control these relays.
I'm hoping it's possible to power the arduino from the existing Transverter, since it's sitting there installed anyway.
From what I've read, it looks like I should consider Transisters, MOSFETs, H-bridges, and/or additional relays to drive the 28.5Vdc pulse needed to switch the TouchPlate relays.
Since I'm not running motors, but simply supplying enough power to switch these latching relays, do I need to worry about protecting the arduino circuity when switching lights off?
Thanks in advance for any pointers/tips/comments to help my knowledge gathering. I'm sure I'll spend plenty of time with the kids when the arduino arrives just showing them how to get LED's to blink!