This regulator can use BD'136 as the main transistor and as a reference next to a BC548 zener. The circuit provides a voltage of 9V from 12 to power devices that use batteries.
This circuit was found in an American documentation from the 60's. The transistors are from the...
This oscillator is indicated for the adjustment of FI of FM radios, having its frequency...
This configuration triggers an external circuit or simply an LED for time given by R1 and C1 (T =...