This simple low power triplicator was found in 90’s American documentation. The diodes can be general purpose types and the frequency is determined by the RC network of the 555.
A bridge with greater sensitivity and, therefore, lower consumption for the microcontroller...
LTC7841 PolyPhase® Synchronized Boost Controllers Mouser Announces Analog Devices LTC7841...
This sinusoidal oscillator was found in Radio Electronics in 1989. It uses a 741, but other...