This is an interesting configuration of the LM317 voltage regulator found in an EDN from the 90s. The circuit uses an optical coupler and is intended to supply constant current to a sensor resistor.
This circuit was found in the October 1994 issue of Electronics Now magazine. The 40446 IC is a...
Found in a 1967 EEE, this circuit generates a constant amplitude signal, stabilized by a zener...
This circuit is from the November 1974 issue of Radio Electronics magazine. The capacitor...