I wanted to do some high voltage experiments which leads to the need of a high voltage transformer. It seemed to make sense to build the case from aluminium and fill the whole thing with oil. The core is a rather big ferrite core with 5 or 6 primary windings and somewhere around 1500 secondary windings.

The transformer is driven by a MOSFET full bridge. The MOSFETs are connected to a PWM circuit via a gate drive transformer. Frequency and duty cycle are variable (the driver takes care of the dead time).