Transformer WS1 DC Adapter 120 volt / 15 volt pn V3186-06 ( replaced V3186-05 ) for Clack WS1 Valve and other "brands" that use the Clack type of valve under their private label.New = Clack started sending valves with a 15 volt DC transformer after 2017.
And this DC transformer ONLY works with newer Valves / newer Control Boards ( since 2017 ).
HOWEVER... the AC 12 volt transformer ( V3186 ) will operate both Old and New style control boards.
So, this transformer ( AC 12 volt V3186 ) remains the Recommended Replacement for Clack power supply.
When in doubt -- order the AC version and not this DC version ( unless you are positive that is what you have now / are replacing ).