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 version of the Pierce oscillator with the 2N3904 was found in the January 1994 issue of...
This circuit sources a Constant current to a load. The current is determined by R2. In the...
This is a very simple atomic radiation detector circuit using a Geiger-Muller tube. The circuit was...