This simple 1-transistor audio preamplifier appeared in the June 1968 Radio Electronics magazine. The transistor is a general-purpose type of the time. The gain is 14 dB.
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...