Found in Unitrode documentation from the 1980s, this circuit makes use of PUTs, currently common components. The circuit must be powered with voltages around 15 V.
This symmetrical configuration uses two operational amplifiers to obtain the rectification of a...
This circuit was obtained from an Auguist 1974 Everyday Electronics magazine. The circuit is still...
Found in a 1967 Ferranti documentation, this regulator makes use of an operational amplifier of the...