This circuit is from a 1977 Signetics integrated circuit manual. The output transistors can be BD136 and BD237 and the symmetrical supply can be from 6 to 12 V. The voltage gain is 10.
Found in Linear Technology documentation from the 90s, this circuit uses an operational amplifier...
This simple circuit that interrupts the supply of a 12 V load in the event of an overvoltage was found in...
The circuit shown is from National Semiconductor, having been found in the 1994 Linear Application...