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 common emitter amplifier with 43 dB gain was found in the August 1970 issue of Radio...
The diagram below is an application of the Texas Instruments TPS25221 to an ISM controlled power...
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...