Another version of CDU? They comes in handy for track switches and some other accessories like Works better with some "Vintage" RR cars and such also uses push button to active whatever effect. Remote cars unloading, things loading a RR car, etc. The CDU prevents the switch and related "blinking out" the rest of layout when activated.
An Option, Just use an old Laptop "Brick" as the base PSU.
Dell HP and others been using Auto Switch 120/240VAC 60/50 Hz output 19V DC "Bricks" for decades that are UL and other Safety/RFI Certified. (Switcher PSU need FCC etc Certs.) If You don't have one now, can find them easy at Flea Markets and more Cheap or Free. Plus "Newer" Ones are every Efficient to meet EPA Energy Star and same in other Countries and won't get warm or hot like one make in 90's and back.
If have a dead Laptop and related can use the power plug from them so you don't even need to cut the plug on the PSU. This way you don't Void the PSU UL etc. In Turn if you have problems on 120/240 side of things, Insurance and other groups can't say you made X thing "Wrong" and refuse to pay or worse.