This power supply for model railroad was found in a February 1961 Radio Electronics Magazine. The transistor must be mounted on a heatsink and the transformer is a 1,5A secondary winding.
This simple lie detector was found in Popular Electronics. Transistors are commonly used. The...
This one-transistor alarm can be used with much more sensors than the two shown by the figure....
This circuit was obtained in a 1975 documentation. The maximum frequency depends on the diodes and the...