We found this circuit in an Electronic Design. The main integrated circuit is the 4017. The frequencies are determined by the RC circuits as well as the duration of the generated pulse train.
This sophisticated comparator, which may have didactic or practical purposes, was found in a 1980s...
This circuit can supply output voltages from 50 to 250 V regulated under a current of 25 mA at 50 V...
This shield was found on an old EDN. The MOSFET can be of any type according to the controlled...