This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The maximum current is 170 mA. and the integrated circuit is the MAX655 from Maxim.
We found this circuit in a 90s Electronic Design. The frequency is given by the network R C1, C2....
Recommended by 90s a Radio Electronics, this unit uses a transformer with a 70 V x 5 A secondary,...
This “Half adder” circuit uses NAND gates from a 7400. The power supply must be 5 V. ...