This Power supply sources from 500 to 1,000 mA according the transformar and was found in a publication of the year 1958. The diodes can be now the 1N4004 and the transistor should be mounted on a heatsink.
This time base circuit for the oscilloscope was obtained from an Electronics Now from the 90s. The...
This relay time delay circuit was found in the October 1993 issue of Electronics Now magazine. The timing...
RF or even switching transistors like the 2N2222 can be used in this circuit. The capacitors are ceramic...