I just noticed the Dukes has a 2 amp fuse rating, so use a L7812CV which is rated for 1.5 amps ($0.39 from jameco.com).  Same heatsink will work.

Bill,

Just use a 12 volt voltage regulator and a small heat sink.  It costs $0.35 from Jameco.com (part 7812T)  and the heat sink is $0.99 (part 326713).  The voltage regulators can handle up to 35 volts and put out 12 volts at 1 amp, more than enough for the dukes system.

Does anyone have a 28v dukes outflow valve that will trade for a 12 volt   Dukes wants 4000 for the conversion Bill Maddox