Gunrunnerjohn makes a regulator with constant voltage that would work with this.
https://hennings-trains.shopli...regulator-2-pcs.html
So far I haven't had any trouble with using AC power on this.
Tom,
Slight correction, and meant with the best of intentions: Constant current.
Light output from LED's is proportional to current, not voltage. So @gunrunnerjohn's regulator is a current regulator, not a voltage regulator. Think of it as a transformer (power pack) that puts out an adjustable current when you turn the throttle, instead of an adjustable voltage.
To most of us, adjusting current to control something is quite foreign, because almost everything is controlled by voltage -- except for LED's.
Mike