In 1972 I started working at the local transformer factory as an intern. Good training but rough otherwise.

During the first year I did things like transformer winding, potting, machine repairs etc. Definitely a grim setting.

 

In the second year I worked my way into the design group and started working on DC-DC power and switching power supplies. To start with I worked on variants of the NV series encapsulated power supplies. At first I did the schematic design only, but in later models I also deigned the magnetics. The early units were characterized by: Simple single mu-metal transformer, voltage feedback, oscillator with a center tap push pull arrangement. Linear output regulators for each output channel. Later I designed some slightly more complex converters. The most interesting used a combination of current and voltage feedback. This led to a combination of very low idle current and transistor drive proportional with load. NV Data Sheet