This circuit was found in an Electronic World of 1968. The circuit uses power transistors of the time. The transistors are for 25 W of dissipation.
We found this circuit in a 1974 technical documentation. The circuit can be made with BC549...
The operational amplifier of this configuration from the 70s is the 741 in its Motorola version from...
This circuit is used to test PNP or NPN transistors giving the status indication through LEDs. The...