Found in a Motorola's 1968 documentation, this circuit operates at 16.5 kHz. The output is 5 A. The transistors are from the era, admitting modern equivalents.
Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to...
This circuit has appeared several times on this site in different applications. This is from 1997...
This setting appears other times in this section from other sources. This is from an 80's American...