(Yet another) HV power supply using the Tentlabs MEC
(Photos are hyperlinked to higher resolution images - just click on them).
I designed this power supply board to power the high voltages for use in a SE amp using the rare 4304CB / VT-62 / or 834 triode. It can be used in many other applications as well. It can generate a high voltage B+, a voltage of 1/2 the B+ (useful for a screen grid or driver supply), plus one other rail that is typically used for a negative voltage, but can be used as a positive supply as well.
The board as I used it generates voltage of 450V, 225V, and -100V. It does this using a center tapped HV winding plus a second isolated winding for the negative supply. Instead of big chokes I used Tentlabs MEC-200 electronic chokes. These things are awesome... you can order them directly from the Tentlabs online shop. (Note that it seems the MEC-100 has been replaced with the MEC-200).
Here's the schematic (or download a PDF file of it):
Pretty straightforward...
I installed 4.7 ohm resistors at R1 and R2. I don't think they are needed but it was easier than a wire :)
I powered this from a custom transformer that provided 360 VCT and 87V. With that I got about 450V (load is 100mA), 245V (load is about 20mA), and -100V (load is about 20mA).
Here's the PCB layout:
...and the bare board:
Here is the parts list (BOM, bill of materials) in .XLS and .PDF forms.