Anyone know how to make a latching circuit with fire alarms and light switches ? I’m making a homemade fire alarm control panel. (I can also buy anything else that’s needed)
I know NewAgeServerAlarm once made a simple relay-based panel that he called the “5001-DC”, not sure where the schematic for it might be found today though (it was on his website but that’s been dead for years).
Relays, connect the positive terminal to the common terminal, and then connect a positive supply to NO and trip supply to the Positive terminal. Now whenever power is sent through the trip supply it switches the relay to the NO state and that sends the power from the supply to the common terminal and then the positive terminal keeping it on. If you want to turn it off just disconnect both supplys momentarily.