Doc here,

imp:
Agreed with Vicrod, It must be some kind of step up transformer driven by some type of "Chopper" Transistors, with a duty cycle..If I were to guess, Be interesting to "Peek" inside..Current output must be limited (as small as that looks).
Lot of money for +3 volts..
Have you looked into an 18 volt battery pricing? Less parts to fail..
Doc

imp: