Found in a Popular Electronics from the 1990s, this circuit is a 1-digit counter that advances under the command of S2. The circuit can be expanded to more digits.
This VHF receiver with three transistors and loudspeaker listening was found in European...
This sensor was published in Radio Electronics magazine in April 1962. The two-transistor circuit...
This circuit consists of a monostable multivibrator using the LM3900 transconductance operational...