Hi, I am looking to design a circuit board that will take the 9v DC signal from a smoke detector which will trigger a 1-60sec timer which will then trigger a relay turning off and on an MVHR system(240AC), I am unsure about the transformer properties and bridge rectifier properties to make this work as I have little to no experience with electronics, Any suggestions would be great. (I am using software called Circuit Wizard 3 to design the circuit)