This regulator or voltage reference consists of a variable zener diode. We found it in the June 1984 issue of Radio Electronics magazine. The output current is low.
We found this circuit in a 1990 documentation. The operational amplifiers are type 741 and the LED is...
We found this circuit on an Elektor from the 90s. The frequency is given by capacitor C1. The...
Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be...