This circuit is from an old Japanese publication of 1962. The circuit uses two batteries, one for the filaments of the tubes and the other one of high voltage for the plate circuits.
Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and...
Two NAND gates are used in the configuration shown here to perform as a monostable triggered by...
Found in a 1980s American documentation, this circuit is based on the common CMOS series...