This 5 V power supply for TTL, Shields and microcontrollers is old, and the components can be replaced by modern equivalents. Transistor Q1 can be a TIP31 and Q2 can be a BD135.
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...