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Heater / Filament Supply using Vicor modules

This is a power supply board that I designed for my 520B amplifiers, and also used in "Gossamer" (RAF VT-62 amps).

The supply has a power-up delay section that delays the application of AC power to the B+ supply, and two DC filament / heater supplies that use Vicor DC/DC modules.  The AC front end (rectifier) uses a Vicor AC input module.

Here's the schematic (download a readable PDF):

I am a fan of Vicor modules.  But they are insanely expensive.  The only way I would do this is to locate appropriate modules on eBay. I found some 300VDC in, 6.5V 7A small modules (VI-711555B) for cheap on eBay, and 5V and 10V VI-Jxx modules, as well as a FARM1C22 AC input module, for reasonable prices (maybe $50 each).  So I designed around them.

The output voltage of Vicor modules can be trimmed over a fairly wide range, so the 6.5V module is set for 6.3V for driver tubes, and the 10V module is set for 5V (for the 530B) or 7.5V (for the VT-62).

The Vicor DC/DC modules have some nice features.  They run at very high switching frequency, so noise isn't a problem.

The PCB layout looks like this (download a PDF):


The modules are mounted to the back side of the PCB, so they can be bolted to a chassis to act as a heatsink.


As of now I do not plan to sell these PCBs, as it's a bit of a, uh, unique thing.  If you really want to build this and are willing to source the modules, make your own parts list, etc. contact me.