This powerful motor control was found in a Philips publication from 1970. The components are from that time and the circuit was designed for the 220/240 V power grid.
This circuit with power MOSFETs was found in a 1980s Siliconix documentation. Equivalent MOSFETs...
This electrochemical circuit monitors the conductivity of the oil indicating when to change it. The...
This circuit, from a 1978 publication, emits a modulated signal when the fine sensor is...