D1, D2, C1, and C2 form a half wave bridge voltage doubler. R1 and R5 discharge the capacitors when the unit is unplugged. R2 serves as the ballast, limiting current in the tube, while R3 and R4 provide current to heat the cathodes. Running the tube from DC can't be good for it under the best of circumstances but I would hope these typically last longer than this one did.
- posted
14 years ago