120vac to 24vac transformer for sprinkler/irrigation solenoids - lightweight solutions?
my soldering iron runs at 26VAC  and to install a 12V timer I used a bridge rectifier and a LM2596HV buck module. (which cost a about a buck)  they have adjustable output voltage so you could turn it down to 5v to for your relay controller.







simulate this circuit &ndash; Schematic created using CircuitLab