Small power regulator PCB, with AC inputs and DC output.
The LT3042 has a very nice way to set the output voltage. Instead of using an internal voltage reference and an external voltage devider, a constant current is driven through a user settable resistance, which is then the reference voltage!
U_out = 100uA * R1||R2
e.g. with R1||R2 = 50kΩ, U_out = 5V