This high voltage oscillator with a neon lamp was found in a 1969 documentation. The circuit is synchronized by pulses of 1 kHz. The power voltage is 160 V.
This interesting capacitive water level sensor was found in Popular Electronics. The circuit can be...
LTC7841 PolyPhase® Synchronized Boost Controllers Mouser Announces Analog Devices LTC7841...
This circuit was fond in an old publication of the years 1950. The transistors are germanium types and...