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300V AC/DC Variable Power Supply

This 300V AC/DC variable PSU is designed for our vacuum-tube, MOSFET and some IGBT related experiments. This PSU consist with 0-300V Variac (variable auto-transformer), 700VA isolation transformer, which is described in previous blog post and high voltage AC-DC converter. Because of the size and weight of these equipment’s we build this PSU as three separate units.

Complete view of 300V AC/DC variable power supply unit.

This PSU is capable to supply 20V - 300V 2.3A (max.) output in either AC or DC form. This PSU use high voltage and because of that, all the proper construction and precautions are necessary to take. Improper wiring or construction may leads to lethal electrical shock and/or fire. If you are not familiar with high-voltage practices do not attempt this project at home.

Schematic of this PSU is available to download at google drive.

Comments

Anonymous said…
Nice project.

However, unless I am reading it incorrectly, according to the schematic the metallic cases are not connected to a proper earth/safety ground at all.

This is quite hazardous when putting things in sheet-metal enclosures. I generally don't bother for small/low voltage PSU's and things I build that are powered off of 24V or less, but 300V /2.3A is plenty enough to warrant at least grounding the case.
In this project all the enclosures are made with 0.5 inch MDF boards and paint with "metallic" color.

As per the schematic AC/DC output terminals are isolated from ground to prevent any ground-loops.

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