This benchtop power supply with various output voltages from 1.5 to 12 V was found in Radio Electronics magazine from August 1960. The circuit uses power transistors of the time.
For fans of sequential systems, here is another one found in a 1983 publication. Two CMOS...
This circuit, already explored in other applications on this site, allows using a high impedance...
In fact, it is a RF field indicator with an operational amplifier equivalent to the 741. This...