LED Power Supply Design Recommendation
You are producing a regulated 17V voltage. You could use an inexpensive non-isolated buck regulator to produce 3.3V from that. If it was 100% efficient, 3.3V @1A would draw 200mA from the 17V supply. 

It's possible, but not guaranteed, that you might do better by picking a somewhat lower voltage than 17V to regulate down, in which case you could add a second winding to the transformer, wound so as to minimize leakage inductance, and use that semi-regulated supply to run the buck regulator. That probably won't change the efficiency by much, but it might reduce the cost if you can use a lower voltage chip and a smaller inductor.