The DM311 chip, so versatile.
Under the main page for Week 7A the story of how this chip works:
The DM311 chip in the centre of the photograph. The inductor adjacent to it has the feedback winding for the Start circuit and later power to chip circuit. Two nice looking optocouplers are also seen here to the left of the DM311.
Mostly cannibalised PSU from an old throw out computer.
The Toroidal chokes salvaged were:
20µH (smallest toroid in centre)
700µH (yellow core centre of board)
13.5mH (primary and secondary) rear of board
11.5mH (primary and secondary – looked same as choke above but thicker windings) rear of board
The large bifilar wound inductor was not extracted.